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Introduction to Aspen Plus Based on Aspen Plus® 10

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					Aspen Technology, Inc.

Reach Your

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Introduction to Aspen Plus
®

Based on Aspen Plus® 10
May 1998
® 2010年1月4日星期一 ®

Introduction to Aspen Plus

Slide 1
©1997 AspenTech. All rights reserved. ©1997 AspenTech. All rights reserved.

Course Agenda - Day 1
1. 2. 3. Introduction - General Simulation Concepts The User Interface - Graphical Flowsheet Definition Basic Input - Getting Around the Graphical User Interface

4.
5.

Unit Operation Models - Overview of Available Unit Operations
RadFrac - Multistage Separation Model

6.
7.
®

Reactor Models - Overview of Available Reactor Types
Cyclohexane Production Workshop
2010年1月4日星期一 Introduction to Aspen Plus Slide 2
©1997 AspenTech. All rights reserved.

Course Agenda - Day 2
8. Physical Properties - Overview of Thermodynamic Models, Basic Property Analysis and Reporting

9.

Accessing Variables - Making References to Flowsheet Variables

10. Sensitivity Analysis - Studying Relationships Between Process Variables 11. Design Specifications - Meeting Process Objectives 12. Fortran Blocks - Use of In-Line Fortran 13. Windows Interoperability - Transferring Data to and from Other Windows Programs
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Course Agenda - Day 3
14. Heater and HeatX - Heaters and Heat Exchangers

15. Pressure Changers - Pumps, Compressors, Pipes and Valves
16. Flowsheet Convergence - Convergence Blocks, Tear Streams and Flowsheet Sequences 17. Full-Scale Plant Modeling Workshop - Simulate a Methanol Plant

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Introduction to Aspen Plus

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©1997 AspenTech. All rights reserved.

Reach Your

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Introduction
Objective: Introduce general flowsheet simulation concepts and Aspen Plus features

Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

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Introduction • What is flowsheet simulation?
Use of a computer program to quantitatively model the characteristic equations of a chemical process

• Uses underlying physical relationships - Mass and energy balance - Equilibrium relationships - Rate correlations (reaction and mass/heat transfer) • Predicts - Stream flowrates, compositions, and properties - Operating conditions - Equipment sizes
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Advantages of Simulation • Reduces plant design time - Allows designer to quickly test various plant
configurations

•

Helps improve current process - Answers “what if” questions - Determines optimal process conditions within given constraints - Assists in locating the constraining parts of a process (debottlenecking)

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Introduction to Aspen Plus

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General Simulation Problem
What is the composition of stream PRODUCT?
RECYCLE REACTOR COOL FEED REAC-OUT COOL-OUT SEP

PRODUCT

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Introduction to Aspen Plus

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Approaches to Flowsheet Simulation • Sequential Modular - Aspen Plus is a sequential modular simulation program. - Each unit operation block is solved in a certain
sequence.

• Equation Oriented - Aspen Custom Modeler (formerly SPEEDUP) is an equation oriented simulation program. - All equations are solved simultaneously. • Combination - Aspen Dynamics (formerly DynaPLUS) uses the
Aspen Plus sequential modular approach to initialize the steady state simulation and the Aspen Custom Modeler (formerly SPEEDUP) equation oriented approach to solve the dynamic simulation.
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Introduction to Aspen Plus

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Good Flowsheeting Practice
• Build large flowsheets a few blocks at a time. - This facilitates troubleshooting if errors occur. • Ensure flowsheet inputs are reasonable. • Check that results are consistent and realistic.

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Introduction to Aspen Plus

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Important Features of Aspen Plus • Rigorous Electrolyte Simulation • Solids Handling • Petroleum Handling • Data Regression • Data Fit • Optimization • User Routines

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Reach Your

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The User Interface
Objective: Become comfortable and familiar with the Aspen Plus graphical user interface

Aspen Plus References: • User Guide, Chapter 1, The User Interface • User Guide, Chapter 2, Creating a Simulation Model • User Guide, Chapter 4, Defining the Flowsheet
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

12

The User Interface
Run ID Title Bar Menu Bar Next Button Tool Bar

Select Mode button

Model Library

Model Menu Tabs

Status Area Process Flowsheet Window

Reference: Aspen Plus User Guide, Chapter 1, The User Interface
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The User Interface (Continued) • Using the mouse - Left button click
- Select object/field

- Right button click - Double left click

- Bring up menu for selected object/field, or inlet/outlet - Open Data Browser object sheet

Reference: Aspen Plus User Guide, Chapter 1, The User Interface
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Introduction to Aspen Plus

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Graphic Flowsheet Operations • To place a block on the flowsheet:
1. Click on a model category tab in the Model Library. 2. Select a unit operation model. Click the drop-down arrow to select an icon for the model. 3. Click on the model and drag it to the flowsheet where you want to place the block, then release the mouse button.

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Graphic Flowsheet Operations (Continued) • To place a stream on the flowsheet:
1. Click on the STREAMS icon in the Model Library. 2. If you want to select a different stream type (Material, Heat or Work), click the down arrow next to the icon and choose a different type. 3. Click a highlighted port to make the connection. 4. Repeat step 3 to connect the other end of the stream. 5. To place one end of the stream as either a process flowsheet feed or product, click a blank part of the Process Flowsheet window. 6. Click the right mouse button to stop creating streams.

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Graphic Flowsheet Operations (Continued) • To display an Input form for a Block or a Stream in the Data
Browser: 1. Double click the left mouse button on the object of interest.

• To Rename, Delete, Change the icon, provide input or view
results for a block or stream: 1. Select object (Block or Stream) by clicking on it with the left mouse button. 2. Click the right mouse button while the pointer is over the selected object icon to bring up the menu for that object. 3. Choose appropriate menu item.
Reference: Aspen Plus User Guide, Chapter 4, Defining the Flowsheet
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Introduction to Aspen Plus

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Cumene Flowsheet Definition
RECYCLE REACTOR COOL FEED REAC-OUT COOL-OUT SEP

Flash2 Model
PRODUCT

RStoic Model

Heater Model

Filename: CUMENE.BKP

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Benzene Flowsheet Definition Workshop
Objective: Create a graphical flowsheet

-

Choose the appropriate icons for the blocks. Rename the blocks and streams.
VAP1

COOL
FL1 FEED COOL

VAP2

Flash2 Model

Heater Model

FL2 LIQ1

Flash2 Model

When finished, save in backup format (Run-ID.BKP). filename: BENZENE.BKP
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LIQ2 Slide 19
©1997 AspenTech. All rights reserved.

Introduction to Aspen Plus

Reach Your

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Basic Input
Objective: Introduce the basic input required to run an Aspen Plus simulation
Aspen Plus References: • User Guide, Chapter 3, Using Help • User Guide, Chapter 5, Global Information for Calculations • User Guide, Chapter 6, Specifying Components • User Guide, Chapter 7, Physical Property Methods • User Guide, Chapter 9, Specifying Streams • User Guide, Chapter 10, Unit Operation Models • User Guide, Chapter 11, Running Your Simulation
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The User Interface • Pulldown Menus - Used to specify program options and commands • Toolbar - Allows direct access to certain popular functions - Can be moved, hidden, or revealed • Data Browser - Used to navigate the forms - Can be moved, resized, minimized, maximized or
closed

• Forms - Used to enter data and view results for the simulation - Can be comprised of a number of sheets
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The User Interface (Continued) • Object Manager - Allows manipulation of discrete objects of information - Objects can be created, edited, renamed, deleted,
hidden, and revealed (Copy and paste of objects will be possible in Version 10.1)

• Next - Checks if the current form is complete and skips to
next form which requires input

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The Data Browser
Go back
Parent button Units Go forward Previous sheet

Next sheet
Comments Status Next

Menu tree

Status area

Description area

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Help • Help Topics - Contents - Used to browse through the
documentation. The User Guides and Reference Manuals are all included in the help.
the Using Aspen Plus book.

• All of the information in the User Guides is found under

- Index - Used to search for help on a topic using the
index entries Find - Used to search for a help on a topic that includes any word or words

• “What‟s This?” Help - Select “What‟s This?” from the Help menu and then
click on any area to get help for that item.
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Functionality of Forms • When you select a field on a form (click left mouse button
in the field), the prompt area at the bottom of the window gives you information about that field.

• Click the drop-down arrow in a field to bring up a list of
possible input values for that field. - Typing a letter will bring up the next selection on the list that begins with that letter.

• The Tab key will take you to the next field on a form.

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Basic Input • The minimum required inputs (in addition to the
graphical flowsheet) to run a simulation are: - Setup - Components - Properties - Streams - Blocks

• These inputs are all found in folders within the Data
Browser.

• These input folders can be located quickly using the
Data menu or the Data Browser buttons on the toolbar.
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Status Indicators
Symbol Status
Input for the form is incomplete Input for the form is complete No input for the form has been entered. It is optional. Results for the form exist. Results for the form exist, but there were calculation errors. Results for the form exist, but there were calculation warnings. Results for the form exist, but input has changed since the results were generated.

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Introduction to Aspen Plus

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Setup
Most of the commonly used Setup information is entered on the Setup Specifications Global sheet:

• Flowsheet title to be used on reports • Run type • Input and output units • Valid phases (e.g. vapor-liquid or vapor-liquid-liquid) • Ambient pressure
Stream report options are located on the Setup Report Options Stream sheet.
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Setup Specifications Form

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Setup Run Types
Run Type
Flowsheet Standard ASPEN PLUS flowsheet run including sensitivity studies and optimization. Flowsheet runs can contain property estimation, assay data analysis, and/or property analysis calculations. Assay Data Analysis Data Regression A standalone Assay Data Analysis and pseudocomponent generation run Use Assay Data Analysis to analyze assay data when you do not want to perform a flowsheet simulation in the same run. A standalone Data Regression run Use Data Regression to fit physical property model parameters required by ASPEN PLUS to measured pure component, VLE, LLE, and other mixture data. Data Regression can contain property estimation and property analysis calculations. ASPEN PLUS cannot perform data regression in a Flowsheet run. PROPERTIES PLUS setup run Use PROPERTIES PLUS to prepare a property package for use with Aspen Custom Modeler (formerly SPEEDUP) or ADVENT, with third-party commercial engineering programs, or with your company's in-house programs. You must be licensed to use PROPERTIES PLUS. A standalone Property Analysis run Use Property Analysis to generate property tables, PT-envelopes, residue curve maps, and other property reports when you do not want to perform a flowsheet simulation in the same run. Property Analysis can contain property estimation and assay data analysis calculations. Standalone Property Constant Estimation run Use Property Estimation to estimate property parameters when you do not want to perform a flowsheet simulation in the same run.

PROPERTIES PLUS

Property Analysis

Property Estimation

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Setup Units • Units in Aspen Plus can be defined at 3 different levels:
1.
2. 3.

Global Level (“Input Data” & “Output Results” fields on the Setup Specifications Global sheet) Object level (“Units” field in the top of any input form of an object such as a block or stream Field Level

•

Users can create their own units sets using the Setup Units Sets Object Manager. Units can be copied from an existing set and then modified.

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Components • Use the Components Specifications form to specify all the
components required for the simulation.

• If available, physical property parameters for each
component are retrieved from databanks.

• Pure component databanks contain parameters such as
molecular weight, critical properties, etc. The databank search order is specified on the Databanks sheet.

• The Find button can be used to search for components by
component name, formula, component class, molecular weight, boiling point, or CAS number.

• The Electrolyte Wizard can be used to set up an
electrolyte simulation.
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Components Specifications Form

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Entering Components • The Component ID is used to identify the component in
simulation inputs and results.

• Each Component ID can be associated with a databank
component as either: - Formula: Chemical formula of component e.g., C6H6 (Note that a suffix is added to formulas when there are isomers. E.g. C2H6O-2) - Component Name: Full name of component e.g., BENZENE

• Databank components can be searched for using the Find
button. - Search using component name, formula, component class, molecular weight, boiling point, or CAS number. - All components containing specified items will be listed.
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Find

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Pure Component Databanks
Databank Contents
PURE10 AQUEOUS SOLIDS Data from the Design Institute for Physical Property Data (DIPPR) and AspenTech Pure component parameters for ionic and molecular species in aqueous solution Pure component parameters for strong electrolytes, salts, and other solids

Use
Primary component databank in ASPEN PLUS Simulations containing electrolytes Simulations containing electrolytes and solids Solids, electrolytes, and metallurgy applications For upward compatibility

INORGANIC Thermochemical properties for inorganic components in vapor, liquid and solid states PURE93 Data from the Design Institute for Physical Property Data (DIPPR) and AspenTech delivered with ASPEN PLUS 9.3 Data from the Design Institute for Physical Property Data (DIPPR) and AspenTech delivered with ASPEN PLUS 8.5-6 Databank delivered with ASPEN PLUS 8.5-6

PURE856

For upward compatibility

ASPENPCD

For upward compatibility

Parameters missing from the first selected databank will be searched for in subsequent selected databanks.
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Properties • Use the Properties Specifications form to specify the
physical property methods to be used in the simulation.

• Property methods are a collection of models and methods
used to describe pure component and mixture behavior.

• Choosing the right physical properties is critical for
obtaining reliable simulation results.

• Selecting a Process Type will narrow the number of
methods available.

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Properties Specifications Form

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Streams • Use Stream Input forms to specify the feed stream
conditions and composition.

• To specify stream conditions enter two of the following: - Temperature - Pressure - Vapor Fraction • To specify stream composition enter either: - Total stream flow and component fractions - Individual component flows • Specifications for streams that are not feeds to the
flowsheet are used as estimates.
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Streams Input Form

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Blocks • Each Block Input or Block Setup form specifies
operating conditions and equipment specifications for the unit operation model.

• Some unit operation models require additional
specification forms

• All unit operation models have optional information
forms (e.g. BlockOptions form).

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Block Form

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Starting the Run • Select Control Panel from the View menu or press the Next
button to be prompted. - The simulation can be executed when all required forms are complete. - The Next button will take you to any incomplete forms.

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Control Panel
The Control Panel consists of: - A message window showing the progress of the simulation by displaying the most recent messages from the calculations - A status area showing the hierarchy and order of simulation blocks and convergence loops executed - A toolbar which you can use to control the simulation
Run Step Stop Reinitialize Results
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Start or continue calculations Step through the flowsheet one block at a time Pause simulation calculations Purge simulation results Check simulation results
Introduction to Aspen Plus Slide 44
©1997 AspenTech. All rights reserved.

Reviewing Results • History file or Control Panel Messages - Contains any generated errors or warnings - Select History or Control Panel on the View menu to
display the History file or the Control Panel

• Stream Results - Contains stream conditions and compositions
the Data Browser and select the Results form)

• For all streams (/Data/Results Summary/Streams) • For individual streams (bring up the stream folder in

• Block Results - Contains calculated block operating conditions (bring
up the block folder in the Data Browser and select the Results form)
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Cumene Production Conditions
RECYCLE REACTOR COOL FEED

T = 220 F P = 36 psi Benzene: 40 lbmol/hr Propylene: 40 lbmol/hr

REAC-OUT

COOL-OUT

SEP

P = 1 atm Q = 0 Btu/hr

Q = 0 Btu/hr Pdrop = 0 psi

T = 130 F Pdrop = 0.1 psi
PRODUCT

C6H6 + C3H6 = C9H12 Benzene Propylene Cumene (Isopropylbenzene) 90% Conversion of Propylene

Use the RK-SOAVE Property Method Filename: CUMENE.BKP
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Benzene Flowsheet Conditions Workshop
Objective: Add the process and feed stream conditions to a flowsheet.

-

Starting with the flowsheet created in the Benzene Flowsheet Definition Workshop (saved as BENZENE.BKP), add the process and feed stream conditions as shown on the next page.

Questions: 1. What is the heat duty of the block “COOL”? _________ 2. What is the temperature in the second flash block “FL2”? _________ Note: Answers for all of the workshops are located in the very back of the course notes in Appendix C.
Introduction to Aspen Plus Slide 47
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
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Benzene Flowsheet Conditions Workshop
VAP1

COOL FL1 FEED COOL

T = 100 F P = 500 psi
FL2 LIQ1

VAP2

Feed
T = 1000 F P = 550 psi

T = 200 F

P = 1 atm Q=0

Pdrop = 0

Hydrogen: 405 lbmol/hr
Methane: 95 lbmol/hr Benzene: 95 lbmol/hr Toluene: 5 lbmol/hr
LIQ2

Use the PENG-ROB Property Method
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When finished, save as filename: BENZENE.BKP
Slide 48
©1997 AspenTech. All rights reserved.

Introduction to Aspen Plus

Reach Your

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Unit Operation Models
Objective: Review major types of unit operation models

Aspen Plus References: • User Guide, Chapter 10, Unit Operation Models • Reference Manual, Volume 1, Unit Operation Models
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

49

Unit Operation Model Types • Mixers/Splitters • Separators • Heat Exchangers • Columns • Reactors • Pressure Changers • Manipulators • Solids • User Models
Reference: The use of specific models is best described by on-line help and the documentation. • Aspen Plus Reference Manual, Volume 1, Unit Operation Models
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Mixers/Splitters
Model
Mixer

Description
Stream mixer

Purpose
Combine multiple streams into one stream Split stream flows Split substream flows

Use
Mixing tees, stream mixing operations, adding heat streams, adding work streams Stream splitters, bleed valves Solid stream splitters, bleed valves

FSplit SSplit

Stream splitter Substream splitter

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Separators
Model Description Purpose
Flash2 Flash3 Two-outlet flash Determine thermal and phase conditions Three-outlet flash Determine thermal and phase conditions Determine thermal and phase conditions Separate inlet stream components into outlet streams Separate inlet stream components into two outlet streams

Use
Flashes, evaporators, knockout drums, single stage separators Decanters, single stage separators with two liquid phases Decanters, single stage separators with two liquid phases and no vapor phase Component separation operations such as distillation and absorption when the details of the separation are unknown or unimportant Component separation operations such as distillation and absorption when the details of the separation are unknown or unimportant

Decanter Liquid-liquid decanter Sep Component separator

Sep2

Two-outlet component separator

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Heat Exchangers
Model
Heater

Description Purpose
Heater or cooler Determines thermal and phase conditions Two-stream heat exchanger Multistream heat exchanger Interface to BJAC Hetran program Interface to BJAC Aerotran program Exchange heat between two streams Exchange heat between any number of streams Design and simulate shell and tube heat exchangers Design and simulate air-cooled heat exchangers

Use
Heaters, coolers, valves. Pumps and compressors when work-related results are not needed. Two-stream heat exchangers. Rating shell and tube heat exchangers when geometry is known. Multiple hot and cold stream heat exchangers. Two-stream heat exchangers. LNG exchangers. Shell and tube heat exchangers with a wide variety of configurations. Air-cooled heat exchangers with a wide variety of configurations. Model economizers and the convection section of fired heaters.

HeatX

MHeatX

Hetran*

Aerotran*

*
®

Requires separate license
2010年1月4日星期一 Introduction to Aspen Plus Slide 53
©1997 AspenTech. All rights reserved.

Columns - Shortcut
Model
DSTWU

Description

Purpose

Use

Shortcut distillation Determine minimum RR, Columns with one feed and design minimum stages, and either two product streams actual RR or actual stages by Winn-UnderwoodGilliland method. Shortcut distillation Determine separation rating based on RR, stages, and D:F ratio using Edmister method. Shortcut distillation Determine product for petroleum composition and flow, fractionation stages per section, duty using fractionation indices. Columns with one feed and two product streams

Distl

SCFrac

Complex columns, such as crude units and vacuum towers

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Columns - Rigorous
Model
RadFrac

Description Purpose
Rigorous fractionation Rigorous fractionation for complex columns

Use

Rigorous rating and design for single Distillation, absorbers, strippers, columns extractive and azeotropic distillation, reactive distillation Rigorous rating and design for multiple columns of any complexity Heat integrated columns, air separators, absorber/stripper combinations, ethylene primary fractionator/quench tower combinations, petroleum refining Preflash tower, atmospheric crude unit, vacuum unit, catalytic cracker or coker fractionator, vacuum lube fractionator, ethylene fractionator and quench towers Ordinary azeotropic batch distillation, 3phase, and reactive batch distillation

MultiFrac

PetroFrac

Petroleum refining Rigorous rating and design for fractionation petroleum refining applications

BatchFrac*+ RateFrac*

Rigorous batch distillation Rate-based distillation Liquid-liquid extraction

Rigorous rating calculations for single batch columns

Rigorous rating and design for single Distillation columns, absorbers, strippers, and multiple columns. Based on reactive systems, heat integrated units, nonequilibrium calculations petroleum applications Rigorous rating for liquid-liquid extraction columns Liquid-liquid extraction

Extract

*
®

Requires separate license + Input language only in Version 10.0
2010年1月4日星期一 Introduction to Aspen Plus Slide 55
©1997 AspenTech. All rights reserved.

Reactors
Model
RStoic

Description
Stoichiometric reactor Yield reactor

Purpose
Stoichiometric reactor with specified reaction extent or conversion

Use
Reactors where the kinetics are unknown or unimportant but stoichiometry and extent are known

RYield

Reactor with specified yield Reactors where the stoichiometry and kinetics are unknown or unimportant but yield distribution is known Chemical and phase equilibrium by stoichiometric calculations Chemical and phase equilibrium by Gibbs energy minimization Continuous stirred tank reactor Plug flow reactor Single- and two-phase chemical equilibrium and simultaneous phase equilibrium Chemical and/or simultaneous phase and chemical equilibrium. Includes solid phase equilibrium. One, two, or three-phase stirred tank reactors with kinetics reactions in the vapor or liquid One, two, or three-phase plug flow reactors with kinetic reactions in any phase. Plug flow reactions with external coolant. Batch and semi-batch reactors where the reaction kinetics are known

REquil

Equilibrium reactor

RGibbs

Equilibrium reactor

RCSTR RPlug

Continuous stirred tank reactor Plug flow reactor

RBatch

Batch reactor

Batch or semi-batch reactor

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Pressure Changers
Model Description Purpose
Pump Pump or hydraulic turbine Compressor or turbine Change stream pressure when the pressure, power requirement or performance curve is known Change stream pressure when the pressure, power requirement or performance curve is known Change stream pressure across multiple stages with intercoolers. Allows for liquid knockout streams from intercoolers Determine pressure drop or valve coefficient (CV)

Use
Pumps and hydraulic turbines

Compr

Polytropic compressors, polytropic positive displacement compressors, isentropic compressors, isentropic turbines. Multistage polytropic compressors, polytropic positive compressors, isentropic compressors, isentropic turbines. Multi-phase, adiabatic flow in ball, globe and butterfly valves Multi-phase, one dimensional, steady-state and fully developed pipeline flow with fittings Multi-phase, one dimensional, steady-state and fully developed pipeline flow
Slide 57
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MCompr Multistage compressor or turbine Valve Pipe Control valve

Single-segment Determine pressure drop and pipe heat transfer in single-segment pipe or annular space Multi-segment pipe Determine pressure drop and heat transfer in multi-segment pipe or annular space
Introduction to Aspen Plus

Pipeline

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Manipulators
Model
Mult Dupl

Description

Purpose

Use
Multiply streams for scale-up or scale-down Duplicate streams to look at different scenarios in the same flowsheet Link sections or blocks that use different stream classes

Stream multiplier Multiply stream flows by a user supplied factor Stream duplicator Stream class changer Copy a stream to any number of outlets Change stream class

ClChng

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Slide 58
©1997 AspenTech. All rights reserved.

Solids
Model
Crystallizer Crusher Screen FabFl Cyclone VScrub ESP HyCyc CFuge Filter SWash CCD

Description
Continuous Crystallizer Crushers Screens Fabric filters Cyclones Venturi scrubbers Dry electrostatic precipitators Hydrocyclones Centrifuge filters Rotary vacuum filters Single-stage solids washer Counter-current decanter

Uses
Mixed suspension, mixed product removal (MSMPR) crystallizeer used for the production of a single solid product Gyratory/jaw crusher, cage mill breaker, and single or multiple roll crushers Solids-solids separation using screens Gas-solids separation using fabric filters Gas-solids separation using cyclones Gas-solids separation using venturi scrubbers Gas-solids separation using dry electrostatic precipitators Liquid-solids separation using hydrocyclones Liquid-solids separation using centrifuge filters Liquid-solids separation using continuous rotary vacuum filters Single-stage solids washer Multistage washer or a counter-current decanter
Introduction to Aspen Plus Slide 59
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
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Reach Your

Potential

True

RadFrac
Objective: Discuss the minimum input required for the RadFrac fractionation model, and the use of design specifications and stage efficiencies

Aspen Plus References: • Reference Manual, Volume 1, Unit Operation Models, Chapter 4
Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

60

RadFrac: Rigorous Multistage Separation • Two or three phase simulation of: - Ordinary distillation - Absorption, reboiled absorption - Stripping, reboiled stripping - Azeotropic distillation - Reactive distillation • Configuration options: - Any number of feeds - Any number of side draws - Total liquid draw off and pumparounds - Any number of heaters - Any number of decanters
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Introduction to Aspen Plus

Slide 61
©1997 AspenTech. All rights reserved.

RadFrac Flowsheet Connectivity
Vapor distillate (DV)

Top-Stage or Condenser Heat Duty (Q1) Material (any number) Heat Pumparound Heat Heat (any number) Bottom Stage or Reboiler Heat Duty (QN)

1

Reflux L1 + LW

Heat (optional) Liquid distillate (DL) Water distillate (DW) (opt) D=DL+DV DV:D=DV/D RR=L1/D RW=LW/DW Products (any number)

Decanters Product Return

Boil-up (VN) Nstage

Heat (optional)

Bottoms (B) BR=VN/B

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Introduction to Aspen Plus

Slide 62
©1997 AspenTech. All rights reserved.

RadFrac Setup Configuration

• Specify: - Number of stages - Condenser and reboiler configuration - Two column operating specifications - Valid phases - Convergence
2010年1月4日星期一 Introduction to Aspen Plus
®

Slide 63
©1997 AspenTech. All rights reserved.

RadFrac Setup Streams

• Specify: - Feed stage location - Feed stream convention (see Help)
ABOVE-STAGE: Vapor from feed goes to stage above feed stage Liquid goes to feed stage ON-STAGE: Vapor & Liquid from feed go to specified feed stage
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Introduction to Aspen Plus

Slide 64
©1997 AspenTech. All rights reserved.

RadFrac Setup Pressure

• Specify one of: - Column pressure profile - Top/Bottom pressure - Section pressure drop
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Introduction to Aspen Plus

Slide 65
©1997 AspenTech. All rights reserved.

Methanol-Water RadFrac Column
OVHD RadFrac specifications Total Condenser

FEED
T = 65 C P = 1 bar

COLUMN

Kettle Reboiler
9 Stages Reflux Ratio = 1 Distillate to feed ratio = 0.5 Column pressure = 1 bar Feed stage = 6

BTMS Water: 100 lbmol/hr Methanol: 100 lbmol/hr

Use the NRTL-RK Property Method

Filename: RAD-EX.BKP

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Introduction to Aspen Plus

Slide 66
©1997 AspenTech. All rights reserved.

RadFrac Options • To set up an absorber with no condenser or reboiler, set
condenser and reboiler to none on the RadFrac Setup Configuration sheet.

• Either Vaporization or Murphree efficiencies on either a
stage or component basis can be specified on the RadFrac Efficiencies form.

• Tray and packed column design and rating is possible. • A Second liquid phase may be modeled if the user selects
Vapor-liquid-liquid as Valid phases.

• Reboiler and condenser heat curves can be generated.
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Introduction to Aspen Plus

Slide 67
©1997 AspenTech. All rights reserved.

Plot Wizard •
Use Plot Wizard (on the Plot menu) to quickly generate plots of results of a simulation. You can use Plot Wizard for displaying results for the following operations:

-

Physical property analysis Data regression analysis Profiles for all separation models RadFrac, MultiFrac, PetroFrac and RateFrac

• • •
®

Click the object of interest in the Data Browser to generate plots for that particular object. The wizard guides you in the basic operations for generating a plot. Click on the Next button to continue. Click on the Finish button to generate a plot with default settings.
Introduction to Aspen Plus Slide 68
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

1

Block RADFRAC (RadFrac) Profiles Compositions Y (mole frac) METHANOL Y (mole frac) WATER

0.1 0.2 0.3 0.4 0.5

0.6 0.7 0.8 0.9

1

2

3

4

5 Stage

6

7

8

9

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Introduction to Aspen Plus

Slide 69
©1997 AspenTech. All rights reserved.

Plot Wizard Demonstration •
Use the plot wizard on the column to create a plot of the vapor phase compositions throughout the column.
1
Block COLUMN: Vapor Composition Prof iles
WATER METHANOL

Y (mole frac) 0.25 0.5 0.75
1 2

3

4

5 Stage

6

7

8

9

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Introduction to Aspen Plus

Slide 70
©1997 AspenTech. All rights reserved.

RadFrac DesignSpecs and Vary • Design specifications can be specified and executed
inside the RadFrac block using the DesignSpecs and Vary forms.

• One or more RadFrac inputs can be manipulated to
achieve specifications on one or more RadFrac performance parameters.

• The number of specs should, in general, be equal to the
number of varies.

• The DesignSpecs and Varys in a RadFrac are solved in a

“Middle loop.” If you get an error message saying that the middle loop was not converged, check the DesignSpecs and Varys you have entered.
Introduction to Aspen Plus Slide 71
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
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RadFrac Convergence Problems
If a RadFrac column fails to converge, doing one or more of the following could help: 1. Check that physical property issues (choice of Property Method, parameter availability, etc.) are properly addressed. 2. Ensure that column operating conditions are feasible.

3. If the column err/tol is decreasing fairly consistently, increase the maximum iterations on the RadFrac Convergence Basic sheet.

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Introduction to Aspen Plus

Slide 72
©1997 AspenTech. All rights reserved.

RadFrac Convergence Problems (Continued)
4. Provide temperature estimates for some stages in the column using the RadFrac Estimates Temperature sheet (useful for absorbers). 5. Provide composition estimates for some stages in the column using the RadFrac Estimates Liquid Composition and Vapor Composition sheet (useful for highly non-ideal systems). 6. Experiment with different convergence methods on the RadFrac Setup Configuration sheet. >> When a column does not converge, it is usually beneficial to Reinitialize after making changes.
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Introduction to Aspen Plus

Slide 73
©1997 AspenTech. All rights reserved.

RadFrac Workshop
Part A:

•

Perform a rating calculation of a Methanol tower using the following data: Feed to column: 63.2 wt% Water 36.8 wt% Methanol Total flow of 120,000 lb/hr Pressure 18 psia, saturated liquid
Column specification: 38 trays (40 stages) Feed tray = 23 (stage 24) Total condenser Top stage pressure = 16.1 psia Pressure drop per stage = 0.1 psi Distillate flowrate = 1245 lbmol/hr Molar reflux ratio = 1.3

Use NRTL-RK Property Method
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Introduction to Aspen Plus

Slide 74
©1997 AspenTech. All rights reserved.

RadFrac Workshop (Continued)
Part B:

•

Set up design specifications within the column so the following two objectives are met:

•

99.95 wt% methanol in the distillate 99.90 wt% water in the bottoms

To achieve these specifications, you can vary the distillate rate (8001700 lbmol/hr) and the reflux ratio (0.8-2). Make sure stream compositions are reported as mass fractions before running the problem. Note the condenser and reboiler duties: Condenser Duty Reboiler Duty
2010年1月4日星期一

:_________ :_________
Slide 75
©1997 AspenTech. All rights reserved.

Introduction to Aspen Plus

®

RadFrac Workshop (Continued)
Part C:

•
•

Perform the same design calculation after specifying a 65% Murphree efficiency for each tray. Assume the condenser and reboiler have stage efficiencies of 90%.
How do these efficiencies affect the condenser and reboiler duties of the column?

Part D:

•

Perform a tray sizing calculation for the entire column, given that Bubble Cap trays are used.
(When finished, save as filename: RADFRAC.BKP)
2010年1月4日星期一 Introduction to Aspen Plus Slide 76
©1997 AspenTech. All rights reserved.

®

Reach Your

Potential

True

Reactor Models
Objective: Introduce the various classes of reactor models available, and examine in some detail at least one reactor from each class

Aspen Plus References:

• Reference Manual, Volume 1, Unit Operation Models, Chapter 7
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

77

Reactor Overview
Reactors

Balance Based RYield RStoic

Equilibrium Based REquil RGibbs

Kinetics Based RCSTR RPlug RBatch

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 78
©1997 AspenTech. All rights reserved.

Balanced Based Reactors • RYield - Requires a mass balance only, not an atom balance - Is used to simulate reactors in which inlets to the
reactor are not completely known but outlets are (e.g. to simulate a furnace)
1000 lb/hr Coal IN

RYield

70 lb/hr H2O 20 lb/hr CO2 60 lb/hr CO 250 lb/hr tar 600 lb/hr char OUT

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 79
©1997 AspenTech. All rights reserved.

Balanced Based Reactors (Continued) • RStoic - Requires both an atom and a mass balance - Used in situations where both the equilibrium data and

-

the kinetics are either unknown or unimportant Can specify or calculate heat of reaction at a reference temperature and pressure
C, O2 IN RStoic

2 CO + O2 --> 2 CO2 C + O2 --> CO2 2 C + O2 --> 2 CO
C, O2, CO, CO2 OUT

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 80
©1997 AspenTech. All rights reserved.

Equilibrium Based Reactors • GENERAL - Do not take reaction kinetics into account - Solve similar problems, but problem specifications are different Individual reactions can be at a restricted equilibrium

• REquil - Computes combined chemical and phase equilibrium by solving reaction equilibrium equations Cannot do a 3-phase flash Useful when there are many components, a few known reactions, and when relatively few components take part in the reactions

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Introduction to Aspen Plus

Slide 81
©1997 AspenTech. All rights reserved.

Equilibrium Based Reactors (Continued) • RGibbs - Unknown Reactions
This feature is quite useful when reactions occurring are not known or are high in number due to many components participating in the reactions. Gibbs Energy Minimization A Gibbs free energy minimization is done to determine the product composition at which the Gibbs free energy of the products is at a minimum Solid Equilibrium RGibbs is the only Aspen Plus block that will deal with solid-liquid-gas phase equilibrium.
Introduction to Aspen Plus Slide 82
©1997 AspenTech. All rights reserved.

-

-

2010年1月4日星期一
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Kinetic Reactors • Kinetic reactors are RCSTR, RPlug and RBatch. • Reaction kinetics are taken into account, and hence must
be specified.

• Kinetics can be specified using one of the built-in models, or with a user subroutine. The current built-in models are - Power Law - Langmuir-Hinshelwood-Hougen-Watson (LHHW) • A catalyst for a reaction can have a reaction coefficient of
zero.

• Reactions are specified using a Reaction ID.
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Introduction to Aspen Plus

Slide 83
©1997 AspenTech. All rights reserved.

Using a Reaction ID • Reaction IDs are setup as objects, separate from the
reactor, and then referenced within the reactor(s).

• A single Reaction ID can be referenced in any number of
kinetic reactors (RCSTR, RPlug and RBatch.)

• To set up a Reaction ID, go to the Reactions Reactions
Object Manager

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Introduction to Aspen Plus

Slide 84
©1997 AspenTech. All rights reserved.

Power-law Rate Expression
rate  k *  [concentrationi ]exponent i

 Activation Energy  k  ( Pre  exponential Factor) T exp     RT
n

i

Example:

   2 A  3B   C  2 D  k2
k1

Forward reaction: (Assuming the reaction is 2nd order in A and 3rd order in B) coefficients: A: -2 B: -3 C: 1 D: 2 exponents: A: 2 B: 3 C: 0 D: 0 Reverse reaction: (Assuming the reaction is 1st order in C and 2nd order in D) coefficients: C: -1 D: -2 A: 2 B: 3 exponents: C: 1 D: 2 A: 0 B: 0
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 85
©1997 AspenTech. All rights reserved.

Heats of Reaction • Heats of reaction need not be provided for reactions. • Heats of reaction are typically calculated as the difference
between inlet and outlet enthalpies for the reactor (see Appendix A).

• If you have a heat of reaction value that does not match
the value calculated by Aspen Plus, you can adjust the heats of formation (DHFORM) of one or more components to make the heats of reaction match.

• Heats of reaction can also be calculated or specified at a
reference temperature and pressure in an RStoic reactor.

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Introduction to Aspen Plus

Slide 86
©1997 AspenTech. All rights reserved.

Reactor Workshop
Objective: Compare the use of different reactor types to model one reaction.
Reactor Conditions: Temperature = 70 C Pressure = 1 atm
Stoichiometry: Ethanol + Acetic Acid <--> Ethyl Acetate + Water

Kinetic Parameters: Forward Reaction: Pre-exp. Factor = 1.9 x 108, Act. Energy = 5.95 x 107 J/kmol Reverse Reaction: Pre-exp. Factor = 5.0 x 107,Act. Energy = 5.95 x 107 J/kmo
Reactions are first order with respect to each of the reactants in the reaction (second order overall). Reactions occur in the liquid phase. Hint: Check that each reactor is considering both Vapor and Liquid as Valid phases.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 87
©1997 AspenTech. All rights reserved.

Reactor Workshop (Continued)
Use the NRTL-RK property method
P-STOIC F-STOIC RSTOIC

70 % conversion of ethanol

FEED Feed: Temp = 70 C DUPL Pres = 1 atm Water: 8.892 kmol/hr Ethanol: 186.59 kmol/hr Acetic Acid: 192.6 kmol/hr

F-GIBBS

P-GIBBS

RGIBBS

F-PLUG RPLUG

P-PLUG

F-CSTR

Length = 2 meters Diameter = 0.3 meters
P-CSTR

When finished, save as filename: REACTORS.BKP
2010年1月4日星期一
®

RCSTR

Volume = 0.14 Cu. M.
Slide 88
©1997 AspenTech. All rights reserved.

Introduction to Aspen Plus

Reach Your

Potential

True

Cyclohexane Production Workshop

Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

89

Cyclohexane Production Workshop
Objective: Create a flowsheet to model a cyclohexane production process
Cyclohexane can be produced by the hydrogenation of benzene in the following reaction:

C6H6 Benzene

+

3 H2 Hydrogen

=

C6H12 Cyclohexane

The benzene and hydrogen feeds are combined with recycle hydrogen and cyclohexane before entering a fixed bed catalytic reactor. Assume a benzene conversion of 99.8%.
The reactor effluent is cooled and the light gases separated from the product stream. Part of the light gas stream is fed back to the reactor as recycle hydrogen. The liquid product stream from the separator is fed to a distillation column to further remove any dissolved light gases and to stabilize the end product. A portion of the cyclohexane product is recycled to the reactor to aid in temperature control.
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 90
©1997 AspenTech. All rights reserved.

Cyclohexane Production Workshop
C6H6 + 3 H2 = C6H12 Benzene Hydrogen Cyclohexane
PURGE
Total flow = 330 kmol/hr T = 50 C P = 25 bar Molefrac H2 = 0.975 N2 = 0.005 CH4 = 0.02 92% flow to stream H2RCY

H2RCY

VFLOW

H2IN

VAP FEED-MIX RXIN
T = 150C P = 23 bar

REACT HP-SEP RXOUT
T = 200 C Pdrop = 1 bar Benzene conv = 0.998 T = 50 C Pdrop = 0.5 bar

Specify cyclohexane mole recovery of 0.9999 by varying Mole-B from 97 to 101 kmol/hr

LTENDS
Stages = 12 Reflux ratio = 1.2 Bottoms rate = 99 kmol/hr Partial Condenser with vapor distillate only P = 15 bar Feed stage = 8

BZIN
T = 40 C P = 1 bar Benzene flow = 100 kmol/hr

CHRCY LFLOW

COLFD
30% flow to stream CHRCY

PRODUCT

Use the RK-SOAVE property method

COLUMN

When finished, save as filename: CYCLOHEX.BKP
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 91
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

Physical Properties
Objectives:
Introduce the ideas of property methods and physical property parameters Identify issues involved in the choice of a property method Cover the use of Property Analysis for reporting physical properties
Aspen Plus References: • User Guide, Chapter 7, Physical Property Methods • User Guide, Chapter 8, Physical Property Parameters and Data • User Guide, Chapter 29, Analyzing Properties
Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

92

Case Study - Acetone Recovery • Correct choice of physical property models and accurate
physical property parameters are essential for obtaining accurate simulation results.
OVHD FEED

COLUMN

5000 lbmol/hr 10 mole % acetone 90 mole % water

BTMS

Specification: 99.5 mole % acetone recovery

Ideal Approach
Predicted number of stages required Approximate cost in dollars
2010年1月4日星期一
®

Equation of State Approach
7 390,000

Activity Coefficient Model Approach
42 880,000
Slide 93
©1997 AspenTech. All rights reserved.

11 520,000

Introduction to Aspen Plus

How to Establish Physical Properties
Choose a Property Method

Check Parameters/Obtain Additional Parameters

Confirm Results

Create the Flowsheet

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 94
©1997 AspenTech. All rights reserved.

Property Methods • A Property Method is a collection of models and methods
used to calculate physical properties.

• Property Methods containing commonly used
thermodynamic models are provided in Aspen Plus.

• Users can modify existing Property Methods or create
new ones.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 95
©1997 AspenTech. All rights reserved.

Physical Property Models
Approaches to representing physical properties of components Physical Property Models

Ideal

Equation of State (EOS) Models

Activity Coefficient Models

Special Models

• Choice of model types depends on degree of non-ideal
behavior and operating conditions.
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 96
©1997 AspenTech. All rights reserved.

Ideal vs. Non-Ideal Behavior • What do we mean by ideal behavior? y - Ideal Gas law and Raoult‟s law x • Which systems behave as ideal? - Non-polar components of similar size and shape • What controls degree of non-ideality? - Molecular interactions
e.g. Polarity, size and shape of the molecules

• How can we study the degree of non-ideality of a system? - Property plots (e.g. TXY & XY)
y
x
2010年1月4日星期一
®

y
x
Slide 97
©1997 AspenTech. All rights reserved.

Introduction to Aspen Plus

Comparison of EOS and Activity Models
EOS Models
Limited in ability to represent non-ideal liquids Fewer binary parameters required Parameters extrapolate reasonably with temperature Consistent in critical region

Activity Coefficient Models
Can represent highly non-ideal liquids Many binary parameters required Binary parameters are highly temperature dependent Inconsistent in critical region

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Introduction to Aspen Plus

Slide 98
©1997 AspenTech. All rights reserved.

Common Option-Sets • Equation of State Property Methods - PENG-ROB - RK-SOAVE • Activity Coefficient Property Methods - NRTL - UNIFAC - UNIQUAC - WILSON

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Introduction to Aspen Plus

Slide 99
©1997 AspenTech. All rights reserved.

Henry's Law • Henry's Law is only used with ideal and activity coefficient
models.

• It is used to determine the amount of a supercritical
component or light gas in the liquid phase.

• Any supercritical components or light gases (CO2, N2,
etc.) should be declared as Henry's components (Components Henry Comps Selection sheet).

• The Henry's components list ID should be entered on
Properties Specifications Global sheet in the Henry Components field.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 100
©1997 AspenTech. All rights reserved.

Choosing a Property Method - Review
Do you have any polar components in your system?

N
Use EOS Model Y

Y
Are the operating conditions near the critical region of the mixture? N Do you have light gases or supercritical components in your system?

Reference: Aspen Plus User Guide, Chapter 7, Physical Property Methods, gives similar, more detailed guidelines for choosing a Property Method.
2010年1月4日星期一
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Y Use activity coefficient model with Henry‟s Law
Introduction to Aspen Plus

N Use activity coefficient model
Slide 101
©1997 AspenTech. All rights reserved.

Choosing a Property Method - Example
System
Propane, Ethane, Butane Benzene, Water Acetone, Water

Model Type
EOS Activity Coefficient Activity Coefficient

Property Method
RK-SOAVE, PENG-ROB NRTL-RK, UNIQUAC NRTL-RK, WILSON

Choose an appropriate Property Method for the following systems of components at ambient conditions.
System
ethanol, water benzene, toluene acetone, water, carbon dioxide water, cyclohexane ethane and propanol
2010年1月4日星期一
®

Property Method

Introduction to Aspen Plus

Slide 102
©1997 AspenTech. All rights reserved.

How to Establish Physical Properties
Choose a Property Method

Check Parameters/Obtain Additional Parameters

Confirm Results

Create the Flowsheet

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Introduction to Aspen Plus

Slide 103
©1997 AspenTech. All rights reserved.

Pure Component Parameters • Represent attributes of a single component • Input in the Properties Parameters Pure Component
folder.

• Stored in databanks such as PURE10, ASPENPCD,
SOLIDS, etc. (The selected databanks are listed on the Components Specifications Databanks sheet.)

• Parameters retrieved into the Graphical User Interface by
selecting Retrieve Parameter Results from the tools menu.

• Examples - Scalar: MW for molecular weight - Temperature-Dependent: PLXANT for parameters in
the extended Antoine vapor pressure model
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 104
©1997 AspenTech. All rights reserved.

Binary Parameters • Used to describe interactions between two components • Input in the Properties Parameters Binary Interaction
folder

• Stored in binary databanks such as VLE-IG, LLE-ASPEN • Parameter values from the databanks can be viewed on
the input forms in the Graphical User Interface.

• Parameter forms that include data from the databanks
must be viewed before the flowsheet is complete.

• Examples - Scalar: RKTKIJ for the Rackett model - Temperature-Dependent: NRTL for parameters in the
NRTL model
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 105
©1997 AspenTech. All rights reserved.

Reporting Physical Property Parameters
Follow this procedure to obtain a report file containing values of ALL pure component and binary parameters for ALL components used in a simulation: 1. On the Setup Report Options Property sheet, select All physical property parameters used (in SI units) or select Property parameters‟ descriptions, equations, and sources of data. 2. After running the simulation, export a report (*.rep) file (Select Export from the File menu). 3. Edit the .rep file using any text editor. (From the Graphical User Interface, you can choose Report from the View menu.) The parameters are listed under the heading PARAMETER VALUES in the physical properties section of the report file.
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 106
©1997 AspenTech. All rights reserved.

PARAMS and PARAM-PLUS Reports • The PARAM-PLUS report is not as compact as the
PARAMS report; however it has a few advantages:
PARAMS
Parameters are reported in SI units, and the units of the parameters are not printed.

PARAM-PLUS
Parameters are reported in output-units, and the units of the parameters are printed.

Only Aspen Plus abbreviations for Aspen Plus abbreviation along the parameter names are printed. with a description is printed Output is fairly compact. Output is quite long. Equations for temperaturedependent parameters are listed. Source of parameter is given (i.e. databank name or user input).

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 107
©1997 AspenTech. All rights reserved.

How to Establish Physical Properties
Choose a Property Method

Check Parameters/Obtain Additional Parameters

Confirm Results

Create the Flowsheet

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 108
©1997 AspenTech. All rights reserved.

Property Analysis • Used to generate simple property diagrams to validate
physical property models and data

• • • •
®

Diagram Types: - Pure component, e.g. Vapor pressure vs. temperature - Binary, e.g. TXY, PXY - Ternary residue maps Additional binary plots are available under the Plot Wizard button on result form containing raw data. When using a binary analysis to check for liquid-liquid phase separation, remember to choose Vapor-LiquidLiquid as Valid phases. Property analysis input and results can be saved as a form for later reference and use.
2010年1月4日星期一 Introduction to Aspen Plus Slide 109
©1997 AspenTech. All rights reserved.

Property Analysis - Common Plots
Ideal XY Plot:
y-x diagram for METHANOL / PROPANOL

XY Plot Showing Azeotrope:
y-x diagram for ETHANOL / TOLUENE

(PRES = 14.69595 PSI)

(PRES = 14.69595 PSI)

0

0.2 0.4 0.6 0.8 1 LIQUID MOLEFRAC METHANOL

0

0.2 0.4 0.6 0.8 1 LIQUID MOLEFRAC ETHANOL

XY Plot Showing 2 liquid phases:
y-x diagram for TOLUENE / WATER

(PRES = 14.69595 PSI)

0

0.2 0.4 0.6 0.8 1 LIQUID MOLEFRAC TOLUENE

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 110
©1997 AspenTech. All rights reserved.

How to Establish Physical Properties
Choose a Property Method

Check Parameters/Obtain Additional Parameters

Confirm Results

Create the Flowsheet

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 111
©1997 AspenTech. All rights reserved.

Establishing Physical Properties - Review
1. Choose Property Method - Select a Property Method based on - Components present in simulation - Operating conditions in simulation - Available data or parameters for the components 2. Check Parameters - Determine parameters available in Aspen Plus databanks

3. Obtain Additional Parameters (if necessary) - Parameters that are needed can be obtained from - Literature searches - Regression of experimental data (Data Regression) - Property Constant Estimation (Property Estimation)
4. Confirm Results - Verify choice of Property Method and physical property data using - Physical Property Analysis
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Introduction to Aspen Plus

Slide 112
©1997 AspenTech. All rights reserved.

Property Sets • A property set (Prop-Set) is a way of accessing a
collection, or set, of properties as an object with a usergiven name. Only the name of the property set is referenced when using the properties in an application.

• Use property sets to report thermodynamic, transport, and
other property values.

• Current property set applications include: - Design specifications, Fortran blocks, sensitivity - Stream reports - Physical property tables (Property Analysis) - Tray properties (RadFrac, MultiFrac, etc.) - Heating/cooling curves (Flash2, MHeatX, etc.)
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Properties included in Prop-Sets • Properties commonly included in property sets include: - VFRAC - Molar vapor fraction of a stream - BETA - Fraction of liquid in a second liquid phase - CPMX - Constant pressure heat capacity for a mixture - MUMX - Viscosity for a mixture • Available properties include: - Thermodynamic properties of components in a mixture - Pure component thermodynamic properties - Transport properties - Electrolyte properties - Petroleum-related properties
Reference: Reference Manual, Volume 3, Physical Property Data, Chapter 4 has a complete list of properties that can be included in a property set.
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Specifying Property Sets • Use the Properties Prop-Sets form to specify properties in
a property set.

• The Search button can be used to search for a property. • All specified qualifiers apply to each property specified,
where applicable.

• Users can define new properties on the Properties
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Advanced User-Properties form by providing a Fortran subroutine.
Introduction to Aspen Plus Slide 115
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Predefined Property Sets
Some simulation Templates contain predefined property sets. The following table lists predefined property sets and the types of properties they contain for the General Template:
Predefined Property Set
HXDESIGN THERMAL TXPORT VLE VLLE

Types of Properties
Heat exchanger design Mixture thermal (HMX, CPMX, KMX) Transport Vapor-liquid equilibrium (PHIMX, GAMMA, PL) Vapor-liquid-liquid equilibrium

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Stream Results Options

• On the Setup Report Options Stream sheet, use: - Flow Basis and Fraction Basis check-boxes to specify how stream composition is reported - Property Sets button to specify names of property
sets containing additional properties to be reported for each stream
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Definition of Terms • Property Method - Set of property models and methods
used to calculate the properties required for a simulation

•

Property - Calculated physical property value such as mixture enthalpy

•
• •

Property Model - Equation or equations used to calculate a physical property
Property Parameter - Constant used in a property model Property Set (Prop-Set) - A method of accessing properties so that they can be used or tabulated elsewhere

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Physical Properties Workshop
Objective: Simulate a two-liquid phase settling tank and investigate the physical properties of the system.
A refinery has a settling tank that they use to decant off the water from a mixture of water and a heavy oil. The inlet stream to the tank also contains some carbon-dioxide and nitrogen. The tank and feed are at ambient temperature and pressure (70o F, 1atm), and have the following flow rates of the various components: Water Oil CO2 N2 515 lb/hr 4322 lb/hr 751 lb/hr 43 lb/hr

Use the compound n-decane to represent the oil. It is known that water and oil form two liquid phases under the conditions in the tank.
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Physical Properties Workshop (Continued)
1. Choose an appropriate Property Method to represent this system. Check to see that the required binary physical property parameters are available.

2. Using the property analysis feature, verify that the chosen physical property model and the available parameters predict the formation of 2 liquid phases.
3. Set up a simulation to model the settling tank. Use a Flash3 block to represent the tank. 4. Modify the stream report to include the constant pressure heat capacity (CPMX) for each phase (V, L1 and L2), and the fraction of liquid in a second liquid phase (BETA), for all streams. 5. Retrieve the physical property parameters used in the simulation and determine the critical temperature for carbon dioxide and water. TC(carbon dioxide) = _______; TC(water) = _______
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Physical Properties Workshop (Continued)
Optional Part: Objective: Generate a table of compositions and vapor pressure for each liquid phase (L1 and L2) at different temperatures for a mixture of water and oil.

• •

In addition to the interactive Analysis commands under the Tools menu, you also can create a Property Analysis manually, using forms. Manually generated Properties Analyses are created using the Properties Analysis Object Manager.

•
•

Manually created Property Analyses can be executed at the end of a flowsheet simulation or as a stand-alone run using a Run-Type of Property Analysis.
A manually generated Generic Property Analysis is similar to the interactive Analysis commands, however it is more flexible regarding input and reporting. Detailed instruction are on the following slide.
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Physical Properties Workshop (Continued)
Problem Specifications: 1. Create a Generic type property analysis. 2. Generate points along a flash curve. 3. Define component flows of 50 mole water and 50 mole oil. 4. Set Valid phases to Vapor-liquid-liquid. 5. Vary the temperature from 50 to 400 F.

6. Use a vapor fraction of zero.
7. Tabulate a new property set that includes:

a. Mole fraction of water and oil in the 1st and 2nd liquid phases
b. Mole flow of water and oil in the 1st and 2nd liquid phases c. Beta - the fraction of the 1st liquid to the total liquid d. Pure component vapor pressures of water and oil
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Reach Your

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Accessing Variables
Objective: Become familiar with referencing flowsheet variables
Aspen Plus References: User Guide, Chapter 18, Accessing Flowsheet Variables

•

Related Topics: • User Guide, Chapter 20, Sensitivity • User Guide, Chapter 21, Design Specifications • User Guide, Chapter 19, Fortran Blocks and In-Line Fortran • User Guide, Chapter 22, Optimization • User Guide, Chapter 23, Fitting a Simulation Model to Data
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Why Access Variables?
OVHD

FEED

COLUMN

BTMS

•

What is the effect of the reflux ratio of the column on the purity (mole fraction of component B) of the distillate?

•

To perform this analysis, references must be made to 2 flowsheet quantities, i.e. 2 flowsheet variables must be accessed: 1. The reflux ratio of the column 2. The mole fraction of component B in the stream OVHD
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Accessing Variables • An accessed variable is a reference to a particular
flowsheet quantity, e.g. temperature of a stream or duty of a block.

• Accessed variables can be read from, written to, or both. • Flowsheet result variables (calculated quantities) should
not be overwritten or varied.

• The concept of accessing variables is used in sensitivity
analyses, design-specs, in-line Fortran, optimization etc.

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Variable Categories
Variable Category
Blocks Streams

Type of Variable
Block variables and vectors Stream variables and vectors. Both non-component variables and component dependent flow and composition variables can be accessed. Parameters, balance block and pressure relief variables Property parameters Reactions and chemistry variables Costing variables

Model Utility Property Reactions Costing

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Variable Definition Dialog Box • • • •
When completing a Define sheet, such as on a Fortran, Design specification or Sensitivity form, specify the variables on the Variable Definition dialog box. You cannot modify the variables on the Define sheet itself. On the Variable Definition dialog box, select the variable category and Aspen Plus will display the other fields necessary to complete the variable definition. If you are editing an existing variable and want to change the variable name, click the right mouse button on the Variable Name field. On the popup menu, click Rename.
Introduction to Aspen Plus Slide 127
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Notes
1. If the Mass-Frac, Mole-Frac or StdVol-Frac of a component in a stream is accessed, it should not be modified. To modify the composition of a stream, access and modify the Mass-Flow, Mole-Flow or StdVol-Flow of the desired component. 2. If duty is specified for a block, that duty can be read and written using the variable DUTY for that block. If the duty for a block is calculated during simulation, it should be read using the variable QCALC. 3. PRES is the specified pressure or pressure drop, and PDROP is pressure drop used in calculating pressure profile in heating or cooling curves. 4. Only streams that are feeds to the flowsheet should be varied or modified directly.
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Sensitivity Analysis
Objective: Introduce the use of sensitivity analysis to study relationships between process variables

Aspen Plus References: • User Guide, Chapter 20, Sensitivity Related Topics: • User Guide, Chapter 18, Accessing Flowsheet Variables • User Guide, Chapter 19, Fortran Blocks and In-Line Fortran
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Sensitivity Analysis • Allows user to study the effect of changes in input
variables on process outputs.

• Results can be viewed by looking at the Results form in
the folder for the Sensitivity block.

• Results may be graphed to easily visualize relationships
between different variables.

• Changes made to a flowsheet input quantity in a
sensitivity block do not affect the simulation. The sensitivity study is run independently of the base-case simulation.

• Located under /Data/Model Analysis Tools/Sensitivity
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Sensitivity Analysis Example
RECYCLE REACTOR COOL FEED REAC-OUT COOL-OUT SEP

Filename: CUMENE-S.BKP
PRODUCT

What is the effect of cooler outlet temperature on the purity of the product stream?

• What is the manipulated (varied) variable?
cooler outlet temperature

• What is the measured (sampled) variable?
purity (mole fraction) of cumene in product stream
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Sensitivity Analysis Results
1
Sens itivity S-1 Results Summary

CUMENE PRODUCT PURITY 0.9 0.95
100

150 200 250 VARY 1 COOL PARAM TEMP F

300

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Uses of Sensitivity Analysis • Studying the effect of changes in input variables on
process (model) outputs

• Graphically representing the effects of input variables • Verifying that a solution to a design specification is
feasible

• Rudimentary optimization • Studying time varying variables using a quasi-steadystate approach

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Steps for Using Sensitivity Analysis
1. Specify measured (sampled) variable(s) - These are quantities calculated during the simulation to be used in step 4 (Sensitivity Input Define sheet). 2. Specify manipulated (varied) variable(s) - These are the flowsheet variables to be varied (Sensitivity Input Vary sheet). 3. Specify range(s) for manipulated (varied) variable(s) - Variation for manipulated variable can be specified either as equidistant points within an interval or as a list of values for the variable (Sensitivity Input Vary sheet). 4. Specify quantities to calculate and tabulate - Tabulated quantities can be any valid Fortran expression containing variables defined in step 1 (Sensitivity Input Tabulate sheet).
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Plotting
1. Select the column containing the X-axis variable and then select X-Axis Variable from the Plot menu.

2. Select the column containing the Y-axis variable and then select Y-Axis Variable from the Plot menu.
3. (Optional) Select the column containing the parametric variable and then select Parametric Variable from the Plot menu. 4. Select Display Plot from the Plot menu.

» To select a column, click on the heading of the column
with the left mouse button.
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Notes
1. Only quantities that have been input to the flowsheet should be varied or manipulated. 2. Multiple inputs can be varied. 3. The simulation is run for every combination of manipulated (varied) variables.

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Sensitivity Analysis Workshop
Objective: Use a sensitivity analysis to study the effect of the recycle flowrate on the reactor duty in the cyclohexane flowsheet
Part A: Using the cyclohexane production flowsheet Workshop (saved as CYCLOHEX.BKP), plot the variation of reactor duty (block REACT) as the recycle split fraction in LFLOW is varied from 0.1 to 0.4.
Optional Part B: In addition to the fraction split off as recycle (Part A), vary the conversion of benzene in the reactor from 0.9 to 1.0. Tabulate the reactor duty and construct a parametric plot showing the dependence of reactor duty on the fraction split off as recycle and conversion of benzene. Note: Both of these studies (parts A and B) should be set up within the same sensitivity analysis block. When finished, save as filename: SENS.BKP.
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Design Specifications
Objective: Introduce the use of design specifications to meet process design requirements

Aspen Plus References: • User Guide, Chapter 21, Design Specifications Related Topics: • User Guide, Chapter 18, Accessing Flowsheet Variables • User Guide, Chapter 19, Fortran Blocks and In-Line Fortran • User Guide, Chapter 17, Convergence
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Design Specifications • Similar to a feedback controller • Allows user to set the value of a calculated flowsheet
quantity to a particular value

• Objective is achieved by manipulating a specified input
variable

• No results associated directly with a design specification • Located under /Data/Flowsheeting Options/Design Specs

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Design Specification Example
RECYCLE
REACTOR COOL FEED REAC-OUT COOL-OUT SEP

Filename: CUMENE-D.BKP
PRODUCT

What should the cooler outlet temperature be to achieve a cumene product purity of 98 mole percent?

•

What is the manipulated (varied) variable? cooler outlet temperature

•
•
®

What is the measured (sampled) variable? mole fraction of cumene in stream PRODUCT
What is the specification (target) to be achieved? mole fraction of cumene in stream PRODUCT = 0.98
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Steps for Using Design Specifications
1. Identify measured (sampled) variables These are flowsheet quantities, usually calculated quantities, to be included in the objective function (Design Spec Define sheet). 2. Specify objective function (Spec) and goal (Target) This is the equation that the specification attempts to satisfy (Design Spec Spec sheet). The units of the variable used in the objective function are the units for that type of variable as specified by the Units Set declared for the design specification. 3. Set tolerance for objective function The specification is said to be converged if the objective function equation is satisfied to within this tolerance (Design Spec Spec sheet).
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Steps for Using Design Specifications (Continued)
4. Specify manipulated (varied) variable This is the variable whose value the specification changes in order to satisfy the objective function equation (Design Spec Vary sheet). 5. Specify range of manipulated (varied) variable These are the lower and upper bounds of the interval within which Aspen Plus will vary the manipulated variable (Design Spec Vary sheet). The units of the limits for the varied variable are the units for that type of variable as specified by the Units Set declared for the design specification.

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Notes
1. Only quantities that have been input to the flowsheet should be manipulated.

2. The calculations performed by a design specification are iterative. Providing a good estimate for the manipulated variable will help the design specification converge in fewer iterations. This is especially important for large flowsheets with several interrelated design specifications.
3. The results of a design specification can be found under Data/Convergence/Convergence, by opening the appropriate solver block, and choosing the Results form. Alternatively, the final values of the manipulated and/or sampled variables can be viewed directly on the appropriate Stream/Block results forms.
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Notes (Continued)
4. If a design-spec does not converge:

a. Check to see that the manipulated variable is not at its lower or upper bound.
b. Verify that a solution exists within the bounds specified for the manipulated variable, perhaps by performing a sensitivity analysis. c. Check to ensure that the manipulated variable does indeed affect the value of the sampled variables. d. Try providing a better starting estimate for the value of the manipulated variable.

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Notes (Continued)
e. Try changing the characteristics of the convergence block associated with the design-spec (step size, number of iterations, algorithm, etc.) f. Try narrowing the bounds of the manipulated variable or loosening the tolerance on the objective function to help convergence. g. Make sure that the objective function does not have a flat region within the range of the manipulated variable.

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Design Specification Workshop
Objective: Use a design specification in the cyclohexane flowsheet to fix the heat load on the reactor by varying the recycle flowrate.
The cyclohexane production flowsheet workshop (saved as CYCLOHEX.BKP) is a model of an existing plant. The cooling system around the reactor can handle a maximum operating load of 4.7 MMkcal/hr. Determine the amount of cyclohexane recycle necessary to keep the cooling load on the reactor to this amount. Note: The heat convention used in Aspen Plus is that heat input to a block is positive, and heat removed from a block is negative.

When finished, save as filename: DES-SPEC.BKP
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Fortran Blocks
Objective: Introduce usage of Fortran blocks in Aspen Plus
Aspen Plus References: • User Guide, Chapter 19, Fortran Blocks and In-Line Fortran
Related Topics: • User Guide, Chapter 20, Sensitivity • User Guide, Chapter 21, Design Specifications • User Guide, Chapter 18, Accessing Flowsheet Variables • User Guide, Chapter 22, Optimization
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Fortran Blocks • Allows user to write Fortran to be executed by Aspen Plus • Simple Fortran can be translated by Aspen Plus and does
not need to be compiled.

• A Fortran compiler must be present on the machine where
the Aspen Plus engine is running to compile more complex Fortran code.

• Results of the execution of a Fortran block must be
viewed by directly examining the values of the variables modified by the Fortran block.

• Located under /Data/Flowsheeting Options/Fortran
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Fortran Block Example
Use of a Fortran block to set the pressure drop across a Heater block.
RECYCLE REACTOR COOL FEED REAC-OUT COOL-OUT SEP

V

DELTA-P

PRODUCT

Fortran Block DELTA-P = -10-9 * V2

Filename: CUMENE-F.BKP

Pressure drop across heater is proportional to square of volumetric flow into heater.
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Fortran Block Example (Continued) • Which flowsheet variables must be accessed?
Volumetric flow of stream REAC-OUT
This can be accessed in two different ways: 1. Mass flow and mass density of stream REAC-OUT 2. A prop-set containing volumetric flow of a mixture

Pressure drop across block COOL

• When should the Fortran block be executed?
Before block COOL

• Which variables are read and which are written?
Volumetric flow is read Pressure drop is written
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Uses of Fortran Blocks • Feed-forward control (setting flowsheet inputs based on
upstream calculated values)

• Calling external subroutines

• Input / output to and from external files
• Writing to Control Panel, History File, or Report File • Custom reports
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Steps for Using Fortran Blocks
1. Access flowsheet variables to be used within Fortran - All flowsheet quantities that must be either read from or written to, must be identified (Fortran Input Define sheet). 2. Write Fortran - Includes both non-executable (COMMON, EQUIVALENCE, etc) Fortran (Fortran Input Declarations sheet) and executable Fortran (Fortran Input Fortran sheet) to achieve desired result.

3. Specify location of Fortran block in execution sequence (Fortran Input Sequence sheet) - Specify directly, or - Specify with read and write variables
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Notes
1. Only quantities that have been input to the flowsheet should be overwritten. 2. The rules for writing In-Line Fortran are as follows: a. The Fortran code must begin in column 7 or later.

b. Comment lines must have the letter “C” or a “ ; ” in the first column. c. Column two must be blank.
3. Variable names should not begin with lZ or ZZ.

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Notes (Continued)
4. On the Fortran Input Sequence sheet, the preferred way to specify where the Fortran block should be executed is to list the read and write variables. 5. When using the Fortran WRITE statement, you can use the predefined unit number NTERM to write to the control panel. For example, write(NTERM,*) „Feed Flowrate = „,flow

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Fortran Workshop
Objective: Use a Fortran Block to maintain the methane:water ratio in the feed to a reactor.
In a methane reformer, hydrogen gas is produced by reacting methane with water, generating carbon monoxide as a by-product. The reaction taking place is the following: The feed to the reformer consists of pure methane and water streams. These are mixed and heated prior to being fed to the reformer. The conversion of methane is 99.5%, and the molar ratio of methane to water in the feed is 1:4. Create a flowsheet as shown in the diagram on the following slide. Set up a Sensitivity block and plot a graph showing the variation of reactor duty as the methane flowrate in the feed is varied from 100 to 500 lbmol/hr. Note: The methane:water ratio in the feed must be maintained constant for each Sensitivity case. (Hint: This can be achieved using a Fortran Block.)
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Fortran Workshop (Continued)
CH4 + H2O = 3 H2 + CO

Methane Water Hydrogen Carbon Monoxide

Temperature = 150 F Pressure = 900 psi

CH4

MIX RXIN

REFORMER

Temperature = 70 F Pressure = 15 psi

H2O
Temperature = 1100 F Pressure = 850 psi

RXOUT
Temperature = 1450 F Pressure Drop = 20 psi CH4 conversion = 0.995

Use the Peng-Robinson Property Method When finished, save as filename: Fortran.BKP
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Windows Interoperability
Objective: Introduce the use of windows interoperability to transfer data easily to and from other Windows programs.

Aspen Plus References: • User Guide, Chapter 37, Working with Other Windows Programs • User Guide, Chapter 38, Using the Aspen Plus ActiveX Automation Server
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Windows Interoperability •
Copying and pasting simulation data into spreadsheets or reports

•
• • •

Copying and pasting flowsheet graphics and plots into reports
Creating active links between Aspen Plus and other Windows applications OLE embedding OLE automation

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Windows Interoperability - Examples • Copy simulation results such as column profiles and
stream results - into a spreadsheet for further analysis - into a word processor for reports and documentation - into a design program - into a database for case storage and management

• • •
®

Copy flowsheet graphics and plots - into a word processor for reports - into a slide making program for presentations Copy tabular data from spreadsheets into Aspen Plus for Data Regression, Data-Fit, etc. Copy plots or tables into the Process Flowsheet Window
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Benefits of Windows Interoperability •
Benefits of Copy/Paste/Paste Link - Live data links can be established that update these applications as the process model is changed to automatically propagate results of engineering changes. - The benefits to the engineer are quick and error-free data transfer and consistent engineering results throughout the engineering work process.

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Steps for Using Copy and Paste
1. Select Select the data fields or the graphical objects. - Multiple fields of data or objects can be selected by holding down the CTRL key while clicking the mouse on the fields. - Columns of data can be selected by clicking the column heading, or an entire grid can be selected by clicking on the top left cell. 2. Copy Choose Copy from the Edit menu or type CTRL-C. 3. Paste Click the mouse in the input field where you want the information and choose Paste from the Edit menu or click CTRL-V.
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Copy and Paste Workshop 1
Objective: Use copy and paste to copy and paste the stage temperatures into a spreadsheet.

• Use the Cyclohexane flowsheet workshop (saved as
CYCLOHEX.BKP)

• Copy the temperature profile from COLUMN into a
spreadsheet.

• Generate a plot of the temperature using the plot wizard
and copy and paste the plot into the spreadsheet.

• Save the spreadsheet as CYCLOHEX-result.xls
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Copy and Paste Workshop 2
Objective: Use copy and paste to copy the stream results to a stream input form.

• Use the Cyclohexane flowsheet workshop (saved as
CYCLOHEX.BKP)

• Copy the stream results from stream CHRCY into the
input form.

- Copy the compositions, the temperature and the
pressure separately.

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Creating Active Links • •
When copying and pasting information, you can create active links between input or results fields in Aspen Plus and other applications such as Word and Excel. The links update these applications as the process model is modified to automatically propagate results of engineering changes.

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OLE Embedding • •
What is OLE embedding? - Applications can be used within applications. Uses of OLE embedding - OLE server: Aspen Plus flowsheet graphics can be embedded into a report document, or stream data into a CAD drawing. The simulation model is actually contained in the document, and could be delivered directly with that document. - OLE container: Other windows applications can be embedded within the Aspen Plus simulation.

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OLE Embedding (Continued) •
Benefits of OLE embedding - OLE server: If the recipient of an engineering report, for example, wanted to review the model assumptions, he could access and run the embedded Aspen Plus model directly from the report document. - OLE container: For example, Excel spreadsheets and plots could be used to enhance Aspen Plus flowsheet graphics.

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Steps for Creating Active Links
1. Open both applications. 2. Select the data (or object) that you want to paste and link. 3. Choose Copy from the Edit menu. 4. In the location where you want to paste the link, choose Paste Special from the Edit menu. 5. In the Paste Special dialog box, click the Paste Link radio button.

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Paste Link Demonstration
Objective: Create an active link from Aspen Plus Results into a spreadsheet.

• • • • •
®

Start with the cumene flowsheet demonstration.
Open a spreadsheet and create a cell with the temperature for the cooler in it.

Copy and paste the link into the Aspen Plus flowsheet.
Copy and paste a link with the flow and composition of cumene in the product stream into the spreadsheet.

Change the temperature in the spreadsheet and then rerun the flowsheet. Notice the changes.
Introduction to Aspen Plus Slide 168
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Paste Link Workshop
Objective: Create an active link from Aspen Plus Results into a spreadsheet

•
• • •

Use the Cyclohexane flowsheet workshop (saved as CYCLOHEX.BKP) Copy the Condenser and Reboiler duty results from the RadFrac COLUMN Summary sheet. Use Copy with Format and copy the value, the label and the units. Paste the results into the CYCLOHEX-results.xls spreadsheet as a link. Use Paste Special and choose Link. Change the Reflux ratio in the column to 1 and rerun the flowsheet. Check the spreadsheet to see that the results have changed there also. Notice that the temperature profile results have not changed since they were not pasted as a link.
2010年1月4日星期一 Introduction to Aspen Plus Slide 169
©1997 AspenTech. All rights reserved.

®

Saving Files with Active Links •
Be sure to save both the link source file and the link container file.

•
•

If you save the link source with a different name, you must save the link container after saving the link source.
If you have active links in both directions between the two applications and you change the name of both files, you must do three Save operations: - Save the first application with a new name. - Save the second application with a new name. - Save the first application again.
Introduction to Aspen Plus Slide 170
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
®

Running Files with Active Links •
When you open the link source file, there is nothing special that you need to do.

•
•

When you open the link container file, you will usually see a dialog box asking you if you want to re-establish the links. You can select Yes or No.
To make a link source application visible: - Select Links, from the Edit menu in Aspen Plus. - In the Links dialog box, select the source file and click Open Source. (Note: The Process Flowsheet must be the active window. Links is not an option on the Edit menu if the Data Browser is active.)
Introduction to Aspen Plus Slide 171
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
®

Embedding Objects in the Flowsheet •
You can embed other applications as objects into the Process Flowsheet window.

• •
•

You can do this in two ways: - Using Copy and Paste - Using the Insert dialog box You can edit the object embedded in the flowsheet by double clicking on the object to edit it inside Aspen Plus.
You can also move, resize or attach the object to a block or stream in the flowsheet.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 172
©1997 AspenTech. All rights reserved.

OLE Automation • •
What is OLE automation? - Other programs such as Visual Basic or C++ can be used to control a simulation. Uses of OLE automation - Visual Basic or C++ can be written to access and control process models using a documented interface syntax. - A custom application can be built on top of process models.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 173
©1997 AspenTech. All rights reserved.

OLE Automation (Continued) •
Benefits of OLE automation - A model developer in the Process Engineering department could develop a customized Excel interface to an Aspen Plus model for plant operators, using the Visual Basic for Applications (VBA) macro language.

- A customer might write a top-level C++ program that • pulls data from a process model • uses that data to automatically generate custom
spec sheets • populates a process engineering database • launches a third-party design program
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 174
©1997 AspenTech. All rights reserved.

OLE Automation Demonstration •
Example 1 - Simple run and reinit button are used in the butanol flowsheet. - Files: butanol-demo.xls and butanol.bkp Example 2 - More elaborate Visual Basic code is used to create a general heat exchanger spreadsheet that can access the heat exchangers in any Aspen Plus flowsheet. - Files: olespecsheet.xls and heatx2.bkp

•

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 175
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

Heater and HeatX
Objective: Introduction to the use of the Heater and HeatX unit operation models

Aspen Plus References: • User Guide, Chapter 12, Unit Operation Models
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

176

Working with Heater
The Heater block mixes multiple inlet streams to produce a single outlet stream at a specified thermodynamic state. You can use Heater to represent: - Heaters - Coolers

- Valves - Pumps and Compressors (whenever work-related
results are not needed)

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 177
©1997 AspenTech. All rights reserved.

Heater Input Specifications
Allowed combinations:

•

Pressure (or Pressure drop) and one of: - Outlet temperature - Heat duty or inlet heat stream - Vapor fraction - Temperature change - Degrees of subcooling or superheating Outlet Temperature or Temperature change and one of: - Pressure - Heat Duty - Vapor fraction
Introduction to Aspen Plus Slide 178
©1997 AspenTech. All rights reserved.

•

2010年1月4日星期一
®

Heater Input Specifications (Continued)
For single phase use Pressure (drop) and one of: - Outlet temperature

- Heat duty or inlet heat stream - Temperature change
Vapor fraction of 1 means dew point condition, 0 means bubble point

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 179
©1997 AspenTech. All rights reserved.

Working with HeatX
HeatX can model shell and tube exchanger types like: - Counter current and co-current

- Segmental baffle TEMA E, F, G, H, J and X shells - Rod baffle TEMA E and F shells - Bare and low-finned tubes
HeatX performs: - Full zone analysis - Heat transfer and pressure drop calculations - Sensible heat, nucleate boiling, condensation film coefficient calculations - Built-in or user specified correlations
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 180
©1997 AspenTech. All rights reserved.

Working with HeatX (Continued)
HeatX cannot:

• • •

Perform design calculations Perform mechanical vibration analysis Estimate fouling factors

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 181
©1997 AspenTech. All rights reserved.

Working with HeatX (Continued)
When specifying HeatX, consider:

• • •

Rigorous/detailed calculations or simple/shortcut methods What type of specification How to calculate - Log-mean temperature difference - Heat transfer coefficient - Pressure drop What equipment / geometry specifications are available
Introduction to Aspen Plus Slide 182
©1997 AspenTech. All rights reserved.

•
®

2010年1月4日星期一

HeatX Input Specifications
Select one of the following specifications:

• • •

Heat transfer area or Geometry Exchanger duty For hot or cold outlet stream: - Temperature - Temperature change - Temperature approach - Degrees of superheating / subcooling

- Vapor fraction
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 183
©1997 AspenTech. All rights reserved.

HeatX versus Heater
Consider the following:

• • •

Use HeatX when both sides are relevant. Use Heater when one side (utility) is irrelevant. Use two heaters (coupled by heat stream, Fortran block or design spec) to avoid flowsheet complexity created by HeatX.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 184
©1997 AspenTech. All rights reserved.

Two Heaters versus One HeatX

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 185
©1997 AspenTech. All rights reserved.

Heat Curves
HeatX and Heater are able to calculate Heat Curves (Hcurves).

Tables can be generated for various independent variables (typically duty or temperature) for any property that Aspen Plus can generate.
These tables can be printed, plotted, or exported for use with other heat exchanger design software.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 186
©1997 AspenTech. All rights reserved.

Heat Curves Tabular Results

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 187
©1997 AspenTech. All rights reserved.

Heat Curve Plot

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 188
©1997 AspenTech. All rights reserved.

HeatX Workshop
Objective: Compare the simulation of a heat exchanger that uses water to cool a hydrocarbon mixture using three methods: a shortcut HeatX, a rigorous HeatX and two Heaters connected with a Heat stream.

•

Hydrocarbon stream - Temperature: 200 C - Pressure: 4 bar - Flowrate: 10000 kg/hr - Composition: 50 wt% benzene, 20% styrene, 20% ethylbenzene and 10% water Cooling water - Temperature: 20 C - Pressure: 10 bar - Flow rate: 50000 kg/hr - Composition: 100% water
2010年1月4日星期一 Introduction to Aspen Plus Slide 189
©1997 AspenTech. All rights reserved.

•

®

HeatX Workshop (Continued)

Use the RK-Soave Property Method for the hydrocarbon streams. Use the Steam Tables for the cooling water streams. When finished, save as filename: Heatx.BKP
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 190
©1997 AspenTech. All rights reserved.

HeatX Workshop (Continued)
•
Shortcut HeatX simulation: - Hydrocarbon stream exit has a vapor fraction of 0.1 - No pressure drop in either stream

•
•

Two Heaters simulation: - Use the same specifications as the shortcut HeatX simulation
Rigorous HeatX simulation: - Hydrocarbons in shell leave with a vapor fraction of 0.1 - Shell diameter 1 m, 4 tube passes - 600 bare tubes, 6 m length, pitch 31 mm, 21 mm ID, 25 mm OD - All nozzles 100 mm - 5 baffles, 15% cut - Create heat curves containing all info required for thermal design.
2010年1月4日星期一 Introduction to Aspen Plus Slide 191
©1997 AspenTech. All rights reserved.

®

Reach Your

Potential

True

Pressure Changers
Objective: Introduce the unit operation models used to change pressure: pumps, compressors, and models for calculating pressure change through pipes and valves.

Aspen Plus References: • User Guide, Chapter 12, Unit Operation Models
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

192

Working with the Pump Model • • • • •
The Pump block can be used to simulate: - Pumps

- Hydraulic turbines
Power requirement is calculated or input. A Heater model can be used for pressure change calculations only. Pump is designed to handle a single liquid phase. Vapor-liquid or vapor-liquid-liquid calculations can be specified to determine outlet stream conditions.
Introduction to Aspen Plus Slide 193
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
®

Pump Performance Curves •
Rating can be done by specifying scalar parameters or a pump performance curve.

•

Specify: - Dimensional curves

- Dimensionless curves:

• Head versus flow • Power versus flow

• Head coefficient versus flow coefficient

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 194
©1997 AspenTech. All rights reserved.

Working with the Compr Model •
The Compr block can be used to simulate: - Polytropic centrifugal compressor - Polytropic positive displacement compressor - Isentropic compressor - Isentropic turbine Power requirement is calculated or input.

• • • •
®

A Heater model can be used for pressure change calculations only.
Compr is designed to handle both single and multiple phase calculations. Compr can calculate compressor shaft speed.
Introduction to Aspen Plus Slide 195
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Compressor Performance Curves •
Rating can be done by specifying a compressor performance curve.

•

Specify: - Dimensional curves

- Dimensionless curves: •

• Head versus flow • Power versus flow

• Head coefficient versus flow coefficient

Compr cannot handle performance curves for a turbine.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 196
©1997 AspenTech. All rights reserved.

Work Streams •
Any number of inlet work streams can be specified for pumps and compressors.

•
•

One outlet work stream can be specified for the net work load from pumps or compressors.
The net work load is the sum of the inlet work streams minus the actual (calculated) work.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 197
©1997 AspenTech. All rights reserved.

Working with the Valve Model • •
The Valve block can be used to simulate: - Control valves - Pressure changers Valve relates the pressure drop across a valve to the valve flow coefficient. Valve assumes the flow is adiabatic. Valve determines the thermal and phase condition of the outlet stream.

• • •
®

Valve can perform single or multiple phase calculations.

2010年1月4日星期一

Introduction to Aspen Plus

Slide 198
©1997 AspenTech. All rights reserved.

Working with the Valve Model (Cont.) • •
The effect of head loss from pipe fittings can be included. There are three types of calculations: - Adiabatic flash for specified outlet pressure (pressure changer) - Calculate valve flow coefficient for specified outlet pressure (design) - Calculate outlet pressure for specified valve (rating) Valve can check for choked flow.

• •

Cavitation index can be calculated.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 199
©1997 AspenTech. All rights reserved.

Working with the Pipe Model •
The Pipe block calculates the pressure drop and heat transfer in a single pipe segment.

•
• • •

The Pipeline block can be used for a multiple-segment pipe.
Entrance effects are not modeled.

Pipe can perform single or multiple phase calculations.
If the inlet pressure is known, Pipe calculates the outlet pressure.

•
®

If the outlet pressure is known, Pipe calculates the inlet pressure and updates the state variables of the inlet stream.
Introduction to Aspen Plus Slide 200
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Pressure Changers Workshop
Objective: Add pressure changer unit operations to the Cyclohexane flowsheet.

•

Start with the Cyclohexane Workshop flowsheet (CYCLOHEX.BKP)

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 201
©1997 AspenTech. All rights reserved.

Pressure Changers Workshop (Cont.)
Isentropic 4 bar pressure change 20 bar outlet pressure Globe valve V810 equal percent flow 1.5-in size

Performance Curve Head Flow [m] [cum/hr] 40 2 250 5 300 10 300 20

Carbon Steel Schedule 40 1-in diameter 25-m length

26 bar outlet pressure Filename: ENGUNITS.BKP

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 202
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

Flowsheet Convergence
Objective: Introduce the idea of convergence blocks, tear streams and flowsheet sequences
Aspen Plus References: • User Guide, Chapter 17, Convergence Related Topics: • User Guide, Chapter 20, Sensitivity • User Guide, Chapter 21, Design Specifications • User Guide, Chapter 19, Fortran Blocks and In-Line Fortran • User Guide, Chapter 22, Optimization Plus Introduction to Aspen
®

©1997 AspenTech. All rights reserved.

203

Convergence Blocks • Every design specification and tear stream has an
associated convergence block.

• Convergence blocks determine how guesses for a tear

stream or design specification manipulated variable are updated from iteration to iteration.

• Aspen Plus-defined convergence block names begin with the character “$.” - User defined convergence block names must not begin
with the character “$.”

• To determine the convergence blocks defined by Aspen
Plus, look under the “Flowsheet Analysis” section in the Control Panel messages.

• User convergence blocks can be specified under
/Data/Convergence/Convergence...
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 204
©1997 AspenTech. All rights reserved.

Convergence Block Types
•
Different types of convergence blocks are used for different purposes:
To converge tear streams:

•
®

• WEGSTEIN • DIRECT • BROYDEN • NEWTON To converge design specifications: • SECANT • BROYDEN • NEWTON To converge design specifications and tear streams: • BROYDEN • NEWTON For optimization: • SQP • COMPLEX
Global convergence options can be specified on the Convergence ConvOptions Defaults form.
2010年1月4日星期一 Introduction to Aspen Plus Slide 205
©1997 AspenTech. All rights reserved.

Flowsheet Sequence • To determine the flowsheet sequence calculated by

Aspen Plus, look under the “COMPUTATION ORDER FOR THE FLOWSHEET” section in the Control Panel, or on the left-hand pane of the Control Panel window.
Convergence Sequence form.

• User-determined sequences can be specified on the • User-specified sequences can be either full or partial.

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 206
©1997 AspenTech. All rights reserved.

Tear Streams • Which are the recycle streams? • Which are the possible tear streams?
S7 B1
MIXER

S1

S2

B2
MIXER

S3

B3
FSPLIT

S4

B4
FSPLIT

S5

• A tear stream is one for which Aspen Plus makes an initial
guess, and iteratively updates the guess until two consecutive guesses are within a specified tolerance.

S6

• Tear streams are related to, but not the same as recycle
streams.
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 207
©1997 AspenTech. All rights reserved.

Tear Streams (Continued) • To determine the tear streams chosen by Aspen Plus,

look under the “Flowsheet Analysis” section in the Control Panel. Convergence Tear form.

• User-determined tear streams can be specified on the • Providing estimates for tear streams can facilitate or
speed up flowsheet convergence (highly recommended, otherwise the default is zero).

• If you enter information for a stream that is in a “loop,”
Aspen Plus will automatically try to choose that stream to be a tear stream.
2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 208
©1997 AspenTech. All rights reserved.

Convergence Workshop
Objective: Converge this flowsheet.
100 lbmol/hr T=165 F P=15 psia

T=70 F P=35 psia 50 lbmol/hr Ethylene Glycol FEED
GLYCOL

COLUMN

XH20 = 0.4 XMethanol = 0.3 XEthanol = 0.3

DIST

PREHEATR
BOT-COOL

Area = 65 sqft
FEED-HT

VAPOR

PREFLASH
DP=0 Q=0 LIQ

NSTAGES=10 Mole-RR=5 D:F=0.2 P=1 atm FEEDS ON STAGE 5 DV:D=0

BOT

Use NRTL-RK Property Method

When finished, save as filename: CONVERGE.BKP

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 209
©1997 AspenTech. All rights reserved.

Convergence Workshop (Continued)
Hints for Convergence Workshop:

Questions to ask yourself: - What messages are displayed in the control panel? - Why do some of the blocks show zero flow? - What is the Aspen Plus-generated execution sequence for the flowsheet? - Which stream does Aspen Plus choose as a tear stream? - What are other possible tear streams?
Recommendation: Give initial estimates for a tear stream. - Of the three possible tear streams you could choose, which do you know the most about? (Note: If you enter information for a stream that is in a “loop,” Aspen Plus will automatically choose that stream to be a tear stream and set up a convergence block for it.)

2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 210
©1997 AspenTech. All rights reserved.

Convergence Workshop (Continued)
Questions to ask yourself: - Does the flowsheet converge after entering initial estimates for the tear stream? - If not, why not? (see control panel) - How is the err/tol value behaving, and what is its value at the end of the run? - Does it appear that increasing the number of convergence iterations will help? - What else can be tried to improve this convergence? Recommendation: Try a different convergence algorithm (e.g. Direct, Broyden, or Newton). Note: You can either manually create a convergence block to converge the tear stream of your choice, or you can change the default convergence method for all tear streams on the Convergence ConvOptions Defaults DefaultMethods sheet.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 211
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

Full-Scale Plant Modeling Workshop
Objective: Practice and apply many of the techniques used in this course and learn how to best approach modeling projects

Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

212

General Guidelines • ???

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 213
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Objective: Model a methanol plant. The process being modeled is a methanol plant. The basic feed streams to the plant are Natural Gas, Carbon Dioxide (assumed to be taken from a nearby Ammonia Plant) and Water. The aim is to achieve the methanol production rate of approximately 62,000kg/hr, at a purity of at least 99.95 % wt.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 214
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Front-end Section
Carbon Dioxide Stream – CO2 • Temperature = 43 C • Pressure = 1.4 bar • Flow = 24823 kg/hr • Mole Fraction - CO2 - 0.9253 - H2 - 0.0094 - H2O - 0.0606 - CH4 - 0.0019 - N2 - 0.0028 Natural Gas Stream - NATGAS • Temperature = 26 C • Pressure = 21.7 bar • Flow = 29952 kg/hr • Mole Fraction - CO2 - 0.0059 - CH4 - 0.9539 - N2 - 0.0008 - C2H4 - 0.0391 - C3H8 - 0.0003 2010年1月4日星期一
®

Air to Burner - AIR • Temperature = 366 C • Pressure = 1 atm • Flow = 281946 kg/hr Fuel to Burner - FUEL • Flow = 9436 kg/hr • Conditions and composition are the same as for the natural gas stream Circulation Water - H2OCIRC • Pure water stream • Flow = 410000 kg/hr • Temperature = 195 C • Pressure = 26 bar Makeup Steam - MKUPST • Stream of pure steam • Flow = 40000 kg/hr • Pressure = 26 bar • Vapor Fraction = 1 Introduction to Aspen Plus Slide 215
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Carbon Dioxide Compressor - CO2COMP • Discharge Pressure = 27.5 bar • Compressor Type = 2 stage Natural Gas Compressor - CH4COMP • Discharge Pressure = 27.5 bar • Compressor Type = single stage Reformer Process Side Feed Stream Pre-Heater - FEEDHTR • Exit Temperature = 560 C Saturation Column - SATURATE • RadFrac Block with 1.5 inch metal pall ring packing. • Estimated HETP = 10 x 1.5 inches = 381 mm • Height of Packing = 15 meters • No condenser and no reboiler. Reformer Reactor - REFORMER • Consists of two parts: the Furnace portion and the Steam Reforming portion • Exit Temperature of the Steam Reforming portion = 860 C • Pressure = 18 bar

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 216
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Heat Recovery Section

•

This section consists of a series of heat exchangers and flash vessels used to recover the available energy and water in the Reformed Gas stream. FL1 • Pressure Drop = 0 bar • Heat Duty = 0 MMkcal/hr FL2 • Exit Pressure = 17.7 bar • Heat Duty = 0 MMkcal/hr FL3 • Exit Pressure = 17.4 bar • Heat Duty = 0 MMkcal/hr SYNCOM • Two Stage Polytropic compressor • Discharge Pressure = 82.5 bar • Intercooler Exit Temperature = 40 C

BOILER • Exit temperature = 166 C • Exit Pressure = 18 bar
COOL1 • Exit temperature = 136 C • Exit Pressure = 18 bar COOL2 • Exit temperature = 104 C • Exit Pressure = 19 bar COOL3 • Exit temperature = 85 C • Pressure Drop = 0.1 bar COOL4 • Exit temperature = 40 C • Exit Pressure = 17.6 bar 2010年1月4日星期一
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Introduction to Aspen Plus

Slide 217
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Methanol Synthesis Loop Section
Methanol Reactor - MEOHRXR • Tube cooled reactor • Exit Temperature from the tubes = 240 C • No pressure drop across the reactor • Reactions  CO + H2O <-> CO2 + H2  CO2 + 3H2 <-> CH3OH + H2O  2CH3OH <-> DIMETHYLETHER + H2O  4CO + 8H2 <-> N-BUTANOL + 3H2O  3CO + 5H2 <-> ACETONE + 2H2O E121 • Exit Temperature - 150 C • Exit Pressure - 81 bar E122 • Cold Side Exit Temperature - 120 C E223 • Exit Temperature - 60 C • Exit Pressure - 77.3 bar E124 • Exit Temperature - 45 C • Exit Pressure - 75.6 bar 2010年1月4日星期一
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(Equilibrium) (+15 C Temperature Approach) (Molar extent 0.2kmol/hr) (Molar extent 0.8kmol/hr) (Molar extent 0.3kmol/hr) FL4 • Exit Pressure = 75.6 bar • Heat Duty = 0 MMkcal/hr CIRC • Single stage compressor • Discharge Pressure = 83 bar • Discharge Temperature = 55 C SLPIT1 • Split Fraction = 0.8 to stream 403E SLPIT2 • Stream PURGE = 9000 kg/hr

Introduction to Aspen Plus

Slide 218
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Distillation Section
FL5 • Exit Pressure • Heat Duty M4 5 bar 0 MMkcal/hr

•

For water addition to the crude methanol

Topping Column - TOPPING • Number of Stages = 51 (including condenser and reboiler) • Condenser Type = Partial Vapor/Liquid • Feed stage = 14 • Distillate has both liquid and vapor streams • Distillate rate = 1400 kg/hr • Pressure profile: stage 1 = 1.5 bar and stage 51 = 1.8 bar • Distillate vapor fraction = 99 mol% • Stage 2 heat duty = -7 Mmkcal/hr • Stage 51 heat duty Specified by the heat stream • Reboiler heat duty is provided via a heat stream from a heater block • Valve trays • The column has two condensers. To represent the liquid flow connections a pumparound can be used between stage 1 and 3. 2010年1月4日星期一
®

Introduction to Aspen Plus

Slide 219
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Distillation Section (Continued)
Refining Column - REFINING • Number of Stages = 95 (including condenser and reboiler) • Condenser Type = Total • Distillate Rate = 1 kg/hr • Feed stage = 60 • Liquid Product sidedraw from Stage 4 @ 62000 kg/hr (Stream name – PRODUCT) • Liquid Product sidedraw from Stage 83 @ 550 kg/hr (Stream name – FUSELOIL) • Reflux rate = 188765 kg/hr • Pressure profile: stage 1= 1.5bar and stage 95=2bar • Reboiler heat duty is provided via a conventional reboiler supplemented by a heat strea from a heater block to stage 95 • Valve trays

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 220
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Design Specifications

• • • •

To meet environmental regulations, the bottoms stream must contain no more than 100ppm by weight of methanol as this stream is to be dumped to a nearby river. Adjust the make-up steam MKUPST flow to achieve a desired steam to methane molar ratio of 2.8 in the Reformer feed REFFEED. Adjust the air flow to achieve 2%(vol.) of oxygen in the FLUEGAS stream. Adjust the make-up water flow (stream MKWATER) to the CRUDE stream to achieve a stream composition of 23 wt.% of water in the stream feeding the Topping column (stream TOPFEED) to achieve 100 ppm methanol in the Refining column BTMS stream.

Optional

•

Use Rigorous HeatX Specifications for E122  Rigorous/Countercurrent/Heat Transfer coefficient based on Geometry  Hot side – Tube; Cold side – Shell  Pressure drop on both sides is 0.0 bar  Shell diameter – 1.87m ; TEMA Type - E  Tubes – Bare (Single Pass)  Nominal size – 0.75 in ; BWG – 16 ; Carbon Steel  Total number of tubes – 2651  Length – 15.118m  Triangular tube pitch – 26.8mm  Number of Baffles – 7 ; Baffle Cut – 0.15  Diameter of all nozzles – 0.6m 2010年1月4日星期一 Introduction to Aspen Plus Slide 221
©1997 AspenTech. All rights reserved.

®

Full-Scale Plant Modeling Workshop
Hints

• •

To improve convergence it may be necessary to use Broyden to converge the tear streams Use an appropriate equation of state for the portions of the flowsheet involving gases and use an activity coefficient model for the sections where non-ideal liquids may be present.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 222
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 223
©1997 AspenTech. All rights reserved.

Full-Scale Plant Modeling Workshop
Air Fuel FURNACE MEOHRXR

SYNCOMP COOL4 FL3 COOL2 COOL3 MKUPST M2 FEEDHTR COOL1

SPLIT1 E121 MIX2 CIRC E122 FL4 E223 E124 SPLIT2

FL2

BOILER FL1 H2OCIRC CO2 CO2COMP REFORMER SATURATE

FL5

NATGAS CH4COMP REFINING

TOPPING

M4

MKWATER

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Introduction to Aspen Plus

Slide 224
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Reach Your

Potential

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Additional Topics

Introduction to Aspen Plus
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©1997 AspenTech. All rights reserved.

225

Reach Your

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Maintaining Aspen Plus Simulations
Objective: Introduce how to store simulations and retrieve them from your computer environment

Aspen Plus References: • User Guide, Chapter 15, Managing Your Files
Introduction to Aspen Plus
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©1997 AspenTech. All rights reserved.

226

File Formats in Aspen Plus
File Type Extension
Document Backup Template Input *.apw *.bkp *.apt *.inp

Format Description
Binary ASCII ASCII Text Text Text ASCII Binary File containing simulation input and results and intermediate convergence information Archive file containing simulation input and results Template containing default inputs Simulation input Calculation history shown in the Control Panel Detailed calculation history and diagnostic messages Simulation results File containing arrays and intermediate convergence information used in the simulation calculations Simulation report

Run Message *.cpm History Summary Problem Definition Report *.his *.sum *.appdf

*.rep

Text

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Introduction to Aspen Plus

Slide 227
©1997 AspenTech. All rights reserved.

File Type Characteristics • •
Binary files - machine specific, not transferable - not readable, not printable ASCII files - not machine specific, transferable - contain no control characters, “readable” - not intended to be printed Text files - not machine specific, transferable - readable, can be edited - intended to be printed
Introduction to Aspen Plus Slide 228
©1997 AspenTech. All rights reserved.

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How to Store a Simulation
Three ways to store simulations:

Document (*.apw) Simulation definition Yes Convergence info Yes Results Yes Graphics Yes User readable No Open/save speed High Space requirements High

Backup (*.bkp) Yes No Yes Yes No Low Low

Input (*.inp) Yes No No Yes/No Yes Lowest Lowest

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Introduction to Aspen Plus

Slide 229
©1997 AspenTech. All rights reserved.

Template Files
Template files are used to set your personal preferences:

• • • • • • • • • •
®

Units of measurement

Property sets for stream reports
Composition basis Stream report format

Global flow basis for input specifications
Setting Free-Water option Selection for Stream-Class Property Method (Required) Component list Other application-specific defaults
Introduction to Aspen Plus Slide 230
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Reach Your

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Customizing the Look of Your Flowsheet
Objective: Introduce several ways of annotating your flowsheet to create informative Process Flow Diagrams.

Aspen Plus References: • User Guide, Chapter 14, Annotating Your Flowsheet Related Topics: • User Guide, Chapter 37, Working with Other Windows Programs
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

231

Customizing the Process Flow Diagram • Add annotations
Text Graphics Tables

• •

Add OLE objects
Add a titlebox Add plots or diagrams

Display global data
Stream flowrate, pressure and temperature Heat stream duty Work stream power Block duty and power

•
®

Use PFD mode
Change flowsheet connectivity
Introduction to Aspen Plus Slide 232
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Viewing • Use the View menu to select the elements that you wish
to view: - PFD Mode - Global Data - Annotation - OLE Objects

• All of the elements can be turned on and off
independently.

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Introduction to Aspen Plus

Slide 233
©1997 AspenTech. All rights reserved.

Adding Annotation • •
Use the Draw Toolbar to add text and graphics. (Select Toolbar… from the View menu to select the Draw Toolbar if it is not visible.) To create a stream table, click on the Stream Table button on the Results Summary Streams Material sheet.

•

Annotation objects can be attached to flowsheet elements such as streams or blocks.

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Introduction to Aspen Plus

Slide 234
©1997 AspenTech. All rights reserved.

Example of a Stream Table
Heat and Material Balance Table Stream ID Temperature Pressure Vapor Frac Mole Flow Mass Flow Volume Flow Enthalpy Mole Flow BENZENE PROPYLEN CUMENE Mole Frac BENZENE PROPYLEN CUMENE 0.046 0.095 0.859 0.500 0.500 0.047 0.047 0.906 0.046 0.095 0.859 0.021 0.950 0.029 LBMOL/HR LB/HR CUFT/HR MMBTU/HR LBMOL/HR 2.033 4.224 38.085 40.000 40.000 1.983 1.983 38.017 2.033 4.224 38.085 0.050 2.241 0.069 F PSI COOL-OUT 130.0 14.60 0.054 44.342 4914.202 1110.521 -0.490 FEED 220.0 36.00 1.000 80.000 4807.771 15648.095 1.980 PRODUCT 130.1 14.70 0.000 41.983 4807.772 93.470 -0.513 REAC-OUT 854.7 14.70 1.000 44.342 4914.202 42338.408 2.003 RECYCLE 130.1 14.70 1.000 2.359 106.431 1003.782 0.023

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Introduction to Aspen Plus

Slide 235
©1997 AspenTech. All rights reserved.

Adding Global Data • •
On the Results View sheet when selecting Options from the Tools menu, choose the block and stream results that you want displayed as Global Data. Check Global Data on the View menu to display the data on the flowsheet. 130
15 106
Q Temperature (F) Pressure (psi) Flow Rate (lb/hr)

RECYCLE 220 36 4808 REACTOR 855 15 4914 COOL 130 15 4914 SEP

Duty (Btu/hr)

130

FEED
REAC-OUT Q=0 COOL-OUT Q=-2492499

15
4808

Q=0 PRODUCT

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Introduction to Aspen Plus

Slide 236
©1997 AspenTech. All rights reserved.

Using PFD Mode •
In this mode, you can add or delete unit operation icons to the flowsheet for graphical purposes only.

•
•

Using PFD mode means that you can change flowsheet connectivity to match that of your plant.
PFD-style drawing is completely separate from the graphical simulation flowsheet. You must return to simulation mode if you want to make a change to the actual simulation flowsheet. PFD Mode is indicated by the Aqua border around the flowsheet.
Introduction to Aspen Plus Slide 237
©1997 AspenTech. All rights reserved.

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Examples of When to Use PFD Mode •
In the simulation flowsheet, it may be necessary to use more than one unit operation block to model a single piece of equipment in a plant.

-

For example, a reactor with a liquid product and a vent may need to be modeled using an RStoic reactor and a Flash2 block. In the report, only one unit operation icon is needed to represent the unit in the plant.

•

On the other hand, some pieces of equipment may not need to be explicitly modeled in the simulation flowsheet.

-

For example, pumps are frequently not modeled in the simulation flowsheet; the pressure change can be neglected or included in another unit operation block.
Introduction to Aspen Plus Slide 238
©1997 AspenTech. All rights reserved.

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Annotation Workshop
Objective: Use annotation to create a process flow diagram for the cyclohexane flowsheet
Part A: Using the cyclohexane production Workshop (saved as CYCLOHEX.BKP), display all stream and block global data. Part B: Add a title to the flowsheet diagram.

Part C: Add a stream table to the flowsheet diagram.
Part D: Using PFD Mode, add a pump for the BZIN stream for graphical purposes only.
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Introduction to Aspen Plus

Slide 239
©1997 AspenTech. All rights reserved.

Reach Your

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True

Estimation of Physical Properties
Objectives: Provide an overview of estimating physical property parameters in Aspen Plus

Aspen Plus References: • User Guide, Chapter 30, Estimating Property Parameters • Reference Manual, Volume 2, Physical Property Methods and Models, Chapter 8
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

240

What is Property Estimation? • Property Estimation is a system to estimate parameters
required by physical property models. It can be used to estimate: - Pure component physical property constants - Parameters for temperature-dependent models - Binary interaction parameters for Wilson, NRTL and UNIQUAC - Group parameters for UNIFAC

• Estimations are based on group-contribution methods and
corresponding-states correlations.

• Experimental data can be incorporated into estimation.
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Introduction to Aspen Plus

Slide 241
©1997 AspenTech. All rights reserved.

Using Property Estimation • Property Estimation can be used in two ways: - On a stand-alone basis: Property Estimation Run Type - Within another Run Type: Flowsheet, Property
Analysis, Data Regression, PROPERTIES PLUS or Assay Data Analysis

• You can use Property Estimation to estimate properties for
both databank and non-databank components.

• Property Estimation information is accessed in the
Properties Estimation folder.

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Introduction to Aspen Plus

Slide 242
©1997 AspenTech. All rights reserved.

Estimation Methods and Requirements • User Guide, Chapter 30, Estimating Property Parameters,
has a complete list of properties that can be estimated, as well as the available estimation methods and their respective requirements.

• This same information is also available under the on-line
help in the estimation forms.

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Introduction to Aspen Plus

Slide 243
©1997 AspenTech. All rights reserved.

Steps For Using Property Estimation
1. Define molecular structure on the Properties Molecular Structure form. 2. Enter any experimental data using Parameters or Data forms. - Experimental data such as normal boiling point (TB) is very important for many estimation methods. It should be entered whenever possible. 3. Activate Property Estimation and choose property estimation options on the Properties Estimation Input form.

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Introduction to Aspen Plus

Slide 244
©1997 AspenTech. All rights reserved.

Defining Molecular Structure

• Molecular structure is required for all group-contribution
methods used in Property Estimation. You can: - Define molecular structure in the general format and allow Aspen Plus to determine functional groups, or - Define molecular structure in terms of functional groups for particular methods

Reference: For a list of available group-contribution method functional groups, see Reference Manual, Volume 3, Physical Property Data, Chapter 3.

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Introduction to Aspen Plus

Slide 245
©1997 AspenTech. All rights reserved.

Steps For Defining General Structure
1. Sketch the structure of the molecule on paper. 2. Assign a number to each atom, omitting hydrogen. (The numbers must be consecutive starting with 1.) 3. Go to the Properties Molecular Structure Object Manager, choose the component, and select Edit. 4. On the Molecular Structure General sheet, define the molecule by its connectivity. Describe two atoms at a time:

• Specify the types of atoms (C, O, S, …) • Specify the type of bond that connects the two atoms
(single, double, …)

Note: If the molecule is a non-databank component, on the Components Specifications form, enter a Component ID, but do not enter a Component name or Formula.
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Introduction to Aspen Plus

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Example of Defining Molecular Structure • Example of defining molecular structure for isobutyl
alcohol using the general method

- Sketch the structure of the molecule, and assign a
number to each atom, omitting hydrogen.

C1

C2
C3
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C4

O5

Introduction to Aspen Plus

Slide 247
©1997 AspenTech. All rights reserved.

Example of Defining Molecular Structure • Go to the Properties Molecular Structure Object Manager, • On Properties Molecular Structure General sheet,
describe molecule by its connectivity, two atoms at a time.

choose the component, and select Edit.

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Introduction to Aspen Plus

Slide 248
©1997 AspenTech. All rights reserved.

Atom Types • Current available atom types:
Atom Type C O N S B Si F CL Br I Al
®

Description Carbon Oxygen Nitrogen Sulfur Boron Silicon Fluorine Chlorine Bromine Iodine Aluminum

Atom Type Description P Phosphorous Zn Zinc Ga Gallium Ge Germanium As Arsenic Cd Cadmium Sn Tin Sb Antimony Hg Mercury Pb Lead Bi Bismuth
Slide 249
©1997 AspenTech. All rights reserved.

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Introduction to Aspen Plus

Bond Types • Current available bond types: - Single bond - Double bond - Triple bond - Benzene ring - Saturated 5-membered ring - Saturated 6-membered ring - Saturated 7-membered ring - Saturated hydrocarbon chain
Note: You must assign consecutive atom numbers to Benzene ring, Saturated 5-membered ring, Saturated 6membered ring, Saturated 7-membered ring, and Saturated hydrocarbon chain bonds.
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Introduction to Aspen Plus

Slide 250
©1997 AspenTech. All rights reserved.

Steps For Using Property Estimation
1. Define molecular structure on the Properties Molecular Structure form. 2. Enter any experimental data using Parameters or Data forms. - Experimental data such as normal boiling point (TB) is very important for many estimation methods. It should be entered whenever possible. 3. Activate Property Estimation and choose property estimation options on the Properties Estimation Input form.

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Introduction to Aspen Plus

Slide 251
©1997 AspenTech. All rights reserved.

Example of Entering Additional Data • The following data was obtained for isobutyl alcohol. - Normal boiling point (TB) = 107.6 C - Critical temperature (TC) = 274.6 C - Critical pressure (PC) = 43 bar • Enter this data into the simulation to improve the
estimated values.

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Introduction to Aspen Plus

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©1997 AspenTech. All rights reserved.

Example of Entering Additional Data • Go to the Properties Parameters Pure Component Object • Enter the parameters, the components, and the values.
Manager and create a new Scalar parameter form.

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Introduction to Aspen Plus

Slide 253
©1997 AspenTech. All rights reserved.

Steps For Using Property Estimation
1. Define molecular structure on the Properties Molecular Structure form. 2. Enter any experimental data using Parameters or Data forms. - Experimental data such as normal boiling point (TB) is very important for many estimation methods. It should be entered whenever possible. 3. Activate Property Estimation and choose property estimation options on the Properties Estimation Input form.

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Introduction to Aspen Plus

Slide 254
©1997 AspenTech. All rights reserved.

Activating Property Estimation • To turn on Property Estimation, go to the Properties
Estimation Input Setup sheet, and select one of the following:

- Estimate all missing parameters
Estimates all missing required parameters and any parameters you may request in the optional Pure Component, T-Dependent, Binary, and UNIFAC-Group sheets

- Estimate only the selected parameters
Estimates on the parameter types you select on this sheet (and then specify on the appropriate additional sheets)

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Introduction to Aspen Plus

Slide 255
©1997 AspenTech. All rights reserved.

Property Estimation Notes • You can save your property data specifications,
structures, and estimates as backup files, and import them into other simulations (Flowsheet, Data Regression, Property Analysis, or Assay Data Analysis Run-Types.)

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Introduction to Aspen Plus

Slide 256
©1997 AspenTech. All rights reserved.

Property Estimation Workshop
Objective: Estimate the properties of a dimer, ethycellosolve.

Ethylcellosolve is not in any of the Aspen Plus databanks.

Use a Run Type of Property Estimation, and estimate the properties for the new component. (Detailed instructions are included on the following slide.)
The formula for the component is shown below, along with the normal boiling point obtained from literature. Formula: TB = 195 C
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CH3 - CH2 - O - CH2 - CH2 - O - CH2 - CH2 - OH

Introduction to Aspen Plus

Slide 257
©1997 AspenTech. All rights reserved.

Property Estimation Workshop (Continued)
• • • • • • • • • • • •
®

Open a new run, and change the Run Type on the Setup Specifications Global sheet to Property Estimation. Enter a new non-databank component as Component ID DIMER, on the Components Specifications Selection sheet. On the Properties Molecular Structure Object Manager, select DIMER and click Edit. On the General sheet, enter the structure. Go to the Properties Parameters Pure Component Object Manager and create a scalar parameter form. Enter the normal boiling point (TB) of DIMER as 195 C. Run the estimation, and examine the results. Note that the results of the estimation are automatically written to parameters forms, for use in other simulations. Change the Run Type back to Flowsheet on the Setup Specifications Global sheet. Go to the Properties Estimation Input Setup sheet, and choose Do not estimate any parameters. Now, it is possible to add a flowsheet and use this component.

Save this file as PCES.BKP.
2010年1月4日星期一 Introduction to Aspen Plus Slide 258
©1997 AspenTech. All rights reserved.

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Electrolytes
Objective: Introduce the electrolyte capabilities in Aspen Plus

Aspen Plus References: • User Guide, Chapter 6, Specifying Components • Reference Manual, Volume 2, Chapter 5, Electrolyte Simulations
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Electrolytes Examples • Solutions with acids, bases or salts • Sour water solutions • Aqueous amines or hot carbonate for gas sweetening

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Introduction to Aspen Plus

Slide 260
©1997 AspenTech. All rights reserved.

Characteristics of an Electrolyte System
• Some molecular species dissociate partially or
completely into ions in a liquid solvent

• Liquid phase reactions are always at chemical
equilibrium

• Presence of ions in the liquid phase requires non-ideal
solution thermodynamics

• Possible salt precipitation

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Introduction to Aspen Plus

Slide 261
©1997 AspenTech. All rights reserved.

Types of Components •
Solvents - Standard molecular species - Water

- Methanol - Acetic Acid
•
Soluble Gases - Henry‟s Law components - Nitrogen - Oxygen - Carbon Dioxide

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Introduction to Aspen Plus

Slide 262
©1997 AspenTech. All rights reserved.

Types of Components (Continued) •
Ions - Species with a charge - H3O+

- OH- Na+ - Cl- Fe(CN)63•
Salts - Each precipitated salt is a new pure component. - NaCl(s) - CaCO3(s)

- CaSO4•2H2O (gypsum) - Na2CO3•NaHCO3 •2H2O (trona)
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Introduction to Aspen Plus

Slide 263
©1997 AspenTech. All rights reserved.

Apparent and True Components
•
True component approach - Result reported in terms of the ions, salts and molecular species present after considering solution chemistry Apparent component approach - Results reported in terms of base components present before considering solution chemistry - Ions and precipitated salts cannot be apparent components - Specifications must be made in terms of apparent components and not in terms of ions or solid salts

•

» Results are equivalent.
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Introduction to Aspen Plus

Slide 264
©1997 AspenTech. All rights reserved.

Apparent and True Components Example •
NaCl in water

- Solution chemistry
• NaCl • Na+ + Cl--> <--> Na+ + ClNaCl(s)

- Apparent components
• H2O, NaCl

- True components:

• H2O, Na+, Cl-, NaCl(s)

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Introduction to Aspen Plus

Slide 265
©1997 AspenTech. All rights reserved.

Electrolyte Wizard
• • • • • •
Generates new components (ions and solid salts) Revises the Pure component databank search order so that the first databank searched is now ASPENPCD. Generates reactions among components Sets the Property method to ELECNRTL

Creates a Henry‟s Component list
Retrieves parameters for - Reaction equilibrium constant values - Salt solubility parameters - ELECNRTL interaction parameters - Henry‟s constant correlation parameters
Introduction to Aspen Plus Slide 266
©1997 AspenTech. All rights reserved.

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Electrolyte Wizard (Continued)
•
Generated chemistry can be modified. Simplifying the Chemistry can make the simulation more robust and decrease execution time. It is the user‟s responsibility to ensure that the Chemistry is representative of the actual chemical system.

» Note:

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Introduction to Aspen Plus

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Simplifying the Chemistry
•
Typical modifications include: - Adding to the list of Henry‟s components

- Eliminating irrelevant salt precipitation reactions - Eliminating irrelevant species - Adding species and/or reactions that are not in the
electrolytes expert system database

- Eliminating irrelevant equilibrium reactions

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Introduction to Aspen Plus

Slide 268
©1997 AspenTech. All rights reserved.

Limitations of Electrolytes
•
Restrictions using the True component approach:

- Liquid-liquid equilibrium cannot be calculated. - The following models may not be used:
• Equilibrium reactors: • Kinetic reactors: • Shortcut distillation: • Rigorous distillation:
RGibbs and REquil RPlug, RCSTR, and RBatch

Distl, Dstwu and SCFrac
MultiFrac and PetroFrac

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Introduction to Aspen Plus

Slide 269
©1997 AspenTech. All rights reserved.

Limitations of Electrolytes (Continued)
•
Restrictions using the Apparent component approach:

- Chemistry may not contain any volatile species on
the right side of the reactions.

- Chemistry for liquid-liquid equilibrium may not
contain dissociation reactions.

- Input specification cannot be in terms of ions or solid
salts.

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Introduction to Aspen Plus

Slide 270
©1997 AspenTech. All rights reserved.

Electrolyte Demonstration
Objective: Create a flowsheet using electrolytes.
Create a simple flowsheet to mix and flash two feed streams containing aqueous electrolytes. Use the Electrolyte Wizard to generate the Chemistry.
Temp = 25 C Pres = 1 bar 10 kmol/hr H2O 1 kmol/hr HCl
HCL VAPOR

MIX NAOH MIXED

FLASH

Temp = 25 C MIXER Pres = 1 bar P-drop = 0 10 kmol/hr H2O 1.1 kmol/hr NaOH Adiabatic
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FLASH2

Isobaric Molar vapor fraction = 0.75

LIQUID

Introduction to Aspen Plus

Slide 271
©1997 AspenTech. All rights reserved.

Steps for Using Electrolytes
1. Specify the possible apparent components on the Components Specifications Selection sheet.
2. Click on the Elec Wizard button to generate components and reactions for electrolyte systems. There are 4 steps:

-

Step 1: Define base components and select reaction generation options. Step 2: Remove any undesired species or reactions from the generated list. Step 3: Select simulation approach for electrolyte calculations. Step 4: Review physical properties specifications and modify the generated Henry components list and reactions.

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Introduction to Aspen Plus

Slide 272
©1997 AspenTech. All rights reserved.

Electrolyte Workshop
Objective: Create a flowsheet using electrolytes.
Create a simple flowsheet to model the treatment of a sulfuric acid waste water stream using lime (Calcium Hydroxide). Use the Electrolyte Wizard to generate the Chemistry. Use the true component approach.
Temperature = 25C Pressure = 1 bar Flowrate = 10 kmol/hr 5% sulfuric acid solution

Note: Remove from the chemistry: CaSO4(s) CaSO4•1:2W:A(s)
B1

WASTEWAT

LIME

LIQUID

Temperature = 25C Temperature = 25C P-drop = 0 Pressure = 1 bar Flowrate = 10 kmol/hr 5 mole% lime (calcium hydroxide) solution

When finished, save as filename: ELEC.BKP

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Solids Handling
Objective: Provide an overview of the solid handling capabilities

Aspen Plus References: • User Guide, Chapter 6, Specifying Components • Reference Manual, Volume 2, Physical Property Methods and Models, Chapter 3
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

274

Classes of Components • Conventional Components - Vapor and liquid components - Solid salts in solution chemistry • Conventional Inert Solids (CI Solids) - Solids that are inert to phase equilibrium and salt
precipitation/solubility

• Nonconventional Solids (NC Solids) - Heterogeneous substances inert to phase, salt, and
chemical equilibrium that cannot be represented with a molecular structure
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©1997 AspenTech. All rights reserved.

Specifying Component Type •
When specifying components on the Components Specifications Selection sheet, choose the appropriate component type in the Type column. - Conventional - Conventional Components - Solid - Conventional Inert Solids - Nonconventional - Nonconventional Solids

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Conventional Components •
Components participate in vapor and liquid equilibrium along with salt and chemical equilibrium.

•

Components have a molecular weight.

 e.g. water, nitrogen, oxygen, sodium chloride, sodium ions, chloride ions

 Located in the MIXED substream

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©1997 AspenTech. All rights reserved.

Conventional Inert Solids (CI Solids) •
Components are inert to phase equilibrium and salt precipitation/solubility.

•
•

Chemical equilibrium and reaction with conventional components is possible.
Components have a molecular weight.

 e.g. carbon, sulfur
 Located in the CISOLID substream

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Introduction to Aspen Plus

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©1997 AspenTech. All rights reserved.

Nonconventional Solids (NC Solids) • Components are inert to phase, salt or chemical
equilibrium.

• Chemical reaction with conventional and CI Solid
components is possible.

• Components are heterogeneous substances and do not
have a molecular weight.
e.g. coal, char, ash, wood pulp Located in the NC Solid substream

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Component Attributes • Component attributes typically represent the
composition of a component in terms of some set of identifiable constituents

• Component attributes can be - Assigned by the user - Initialized in streams - Modified in unit operation models • Component attributes are carried in the material stream. • Properties of nonconventional components are
calculated by the physical property system using component attributes.
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Introduction to Aspen Plus

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©1997 AspenTech. All rights reserved.

Component Attribute Descriptions
Attribute Type
PROXANAL

Elements
1. Moisture 2. Fixed Carbon 3. Volatile Matter 4. Ash 1. Ash 2. Carbon 3. Hydrogen 4. Nitrogen 5. Chlorine 6. Sulfur 7. Oxygen 1. Pyritic 2. Sulfate 3. Organic 1. Constituent 1 2. Constituent 2 : 20. Constituent 20

Description
Proximate analysis, weight %dry basis

ULTANAL

Ultimate analysis, weight % dry basis

SULFANAL

Forms of sulfur analysis, weight % of original coal, dry basis General constituent analysis, weight or volume %

GENANAL

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Solid Properties •
For conventional components and conventional solids - Enthalpy, entropy, free energy and molar volume are computed. - Property models in the Property Method specified on the Properties Specification Global sheet are used.

•

For nonconventional solids - Enthalpy and molar volume are computed. - Property models are specified on the Properties Advanced NC-Props form.

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Introduction to Aspen Plus

Slide 282
©1997 AspenTech. All rights reserved.

Solids Properties - Conventional Solids
For Enthalpy, Free Energy, Entropy and Heat Capacity • Barin Equations - Single parameter set for all properties - Multiple parameter sets may be available for selected temperature ranges - List INORGANIC databank before SOLIDS

•

Conventional Equations - Combines heat of formation and free energies of formation with heat capacity models - Aspen Plus and DIPPR model parameters - List SOLIDS databank before INORGANIC
Introduction to Aspen Plus Slide 283
©1997 AspenTech. All rights reserved.

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Solids Properties - Conventional Solids
•
Solid Heat Capacity - Heat capacity polynomial model
oS Cp  C1  C2T  C3T 2 

- Used to calculate enthalpy, entropy and free energy - Parameter name: CPSP01 •
Solid Molar Volume - Volume polynomial model
V S  C1  C2T  C3T 2  C4T 3  C5T 4

C4 C5 C6   T T2 T3

- Used to calculate density - Parameter name: VSPOLY
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Introduction to Aspen Plus

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©1997 AspenTech. All rights reserved.

Solids Properties - Nonconventional Solids •
Enthalpy - General heat capacity polynomial model: ENTHGEN - Uses a mass fraction weighted average - Based on the GENANAL attribute - Parameter name: HCGEN Density - General density polynomial model: DNSTYGEN - Uses a mass fraction weighted average - Based on the GENANAL attribute - Parameter name: DENGEN
Introduction to Aspen Plus Slide 285
©1997 AspenTech. All rights reserved.

•

2010年1月4日星期一
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Solids Properties - Special Models for Coal •
Enthalpy - Coal enthalpy model: HCOALGEN - Based on the ULTANAL, PROXANAL and SULFANAL attributes Density - Coal density model: DCOALIGT - Based on the ULTANAL, PROXANAL and SULFANAL attributes

•

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Introduction to Aspen Plus

Slide 286
©1997 AspenTech. All rights reserved.

Built-in Material Stream Classes
Stream Class
CONVEN* MIXNC MIXCISLD MIXNCPSD MIXCIPSD MIXCINC MIXCINCPSD

Description
Conventional components only Conventional and nonconventional solids Conventional components and inert solids Conventional components and nonconventional solids with particle size distribution Conventional components and inert solids with particle size distribution Conventional components and inert solids and nonconventional solids Conventional components and nonconventional solids with particle size distribution

* system default
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Introduction to Aspen Plus

Slide 287
©1997 AspenTech. All rights reserved.

Unit Operation Models •
General Principles - Material streams of any class are accepted.

- The same stream class should be used for inlet and
-

outlet streams (exceptions: Mixer and ClChng). Attributes (components or substream) not recognized are passed unaltered through the block. substream present (examples: Sep, RStoic). In vapor-liquid separation, solids leave with the liquid. Unless otherwise specified, outlet solid substreams are in thermal equilibrium with the MIXED substream.

- Some models allow specifications for each

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Introduction to Aspen Plus

Slide 288
©1997 AspenTech. All rights reserved.

Solids Workshop 1
Objective: Model a conventional solids dryer.

Dry SiO2 from a water content of 0.5% to 0.1% using air.

Notes: Change the Stream class type to: MIXCISLD. Put the SiO2 in the CISOLID substream. The pressure and temperature has to be the same in all the sub-streams of a stream.

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Introduction to Aspen Plus

Slide 289
©1997 AspenTech. All rights reserved.

Solids Workshop 1 (Continued)
Temp = 190 F Pres = 14.7 psia Flow = 1 lbmol/hr 0.79 mole% N2 0.21 mole% O2

FLASH2

Design specification: 99.9 wt.% SiO2

Temp = 70 F Pres = 14.7 psia 995 lb/hr SiO2 5 lb/hr H2O

Pressure Drop = 0 Adiabatic

Use the SOLIDS Property Method

When finished, save as filename: SOLIDWK1.BKP

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Introduction to Aspen Plus

Slide 290
©1997 AspenTech. All rights reserved.

Solids Workshop 2
Objective: Use the solids unit operations to model the particulate removal from a feed of gasifier off gases.
The processing of gases containing small quantities of particulate materials is rendered difficult by the tendency of the particulates to interfere with most operations (e.g., surface erosion, fouling, plugging of orifices and packing). It is therefore necessary to remove most of the particulate materials from the gaseous stream. Various options are available for this purpose (Cyclone, Bag-filter, Venturi-scrubber, and an Electrostatic precipitator) and their particulate separation efficiency can be changed by varying their design and operating conditions. The final choice of equipment is a balance between the technical performance and the cost associated with using a particular unit. In this workshop, various options for removing particulates from the syngas obtained by coal gasification are compared.
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Process Simulation with ASPEN PLUS Introduction to Aspen Plus

Slide 291
©1997 AspenTech. All rights reserved.

Solids Workshop 2 (Continued)
Temp = 650 C Pres = 1 bar Gas Flowrate = 1000 kmol/hr Ash Flowrate = 200 kg/hr Composition (mole-frac) CO 0.19 CO2 0.20 H2 0.05 H2S 0.02 O2 0.03 CH4 0.01 H2O 0.05 N2 0.35 SO2 0.10

G-CYC CYC
Design Mode High Efficiency Separation Efficiency = 0.9

F-CYC

Temp = 40 C S-CYC Pres = 1 bar Water Flowrate = 700 kmol/hr

LIQ F-SCRUB

Design Mode Separation Efficiency = 0.9

G-SCRUB FEED DUPL S-SCRUB

V-SCRUB
F-ESP G-ESP
Design Mode Separation Efficiency = 0.9 Dielectric constant = 1.5

Particle size distribution (PSD) Size limit wt. % [mu] 0- 44 30 44- 63 10 63-90 20 90-130 15 130-200 10 200-280 15

F-BF

ESP

S-ESP G-BF
Design Mode Max. Pres. Drop = 0.048 bar

When finished, save as filename: SOLIDWK2.BKP
2010年1月4日星期一
®

FAB-FILT

S-BF

Process Simulation with ASPEN PLUS Introduction to Aspen Plus

Slide 292
©1997 AspenTech. All rights reserved.

Solids Workshop 2 (Continued) •
Coal ash is mainly clay and heavy metal oxides and can be considered a non-conventional component.

•

HCOALGEN and DCOALIGT can be used to calculate the enthalpy and material density of ash using the ultimate, proximate, and sulfur analyses (ULTANAL, PROXANAL, SULFANAL). These are specified on the Properties Advanced NC-Props form.
The PSD limits can be changed on the Setup Substreams PSD form.

•

•
®

Use the IDEAL Property Method.
Process Simulation with ASPEN PLUS Introduction to Aspen Plus Slide 293
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Reach Your

Potential

True

Optimization
Objective: Introduce the optimization capability in Aspen Plus

Aspen Plus References: • User Guide, Chapter 22, Optimization Related Topics: • User Guide, Chapter 17, Convergence • User Guide, Chapter 18, Accessing Flowsheet Variables
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

294

Optimization • Used to maximize/minimize an objective function • Objective function is expressed in terms of flowsheet
variables and In-Line Fortran.

• Optimization can have zero or more constraints. • Constraints can be equalities or inequalities. • Optimization is located under /Data/Model Analysis
Tools/Optimization

• Constraint specification is under /Data/Model Analysis
Tools/Constraint
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Introduction to Aspen Plus

Slide 295
©1997 AspenTech. All rights reserved.

Optimization Example
A, B FEED REACTOR A + B --> C + D + E

Desired Product C By-product D Waste Product E

$ 1.30 / lb $ 0.11 / lb $ - 0.20 /lb

A, B, C, D, E PRODUCT

For an existing reactor, find the reactor temperature and inlet amount of reactant A that maximizes the profit from this reactor. The reactor can only handle a maximum cooling load of Q.

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Introduction to Aspen Plus

Slide 296
©1997 AspenTech. All rights reserved.

Optimization Example (Cont.) • What are the measured (sampled) variables? - Outlet flowrates of components C, D, E • What is the objective function to be maximized? - 1.30*(lb/hr C) + 0.11*(lb/hr D) - 0.20*(lb/hr E)

• What is the constraint? - The calculated duty of the reactor can not exceed Q.
• What are the manipulated (varied) variables? - Reactor temperature - Inlet amount of reactant A
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Introduction to Aspen Plus

Slide 297
©1997 AspenTech. All rights reserved.

Steps for Using Optimization
1. Identify measured (sampled) variables.

- These are the flowsheet variables used to calculate
the objective function (Optimization Define sheet).

2. Specify objective function (expression).

- This is the Fortran expression that will be maximized
or minimized (Optimization Objective & Constraints sheet). 3. Specify maximization or minimization of objective function (Optimization Objective & Constraints sheet).

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Introduction to Aspen Plus

Slide 298
©1997 AspenTech. All rights reserved.

Steps for Using Optimization (Cont.)
4. Specify constraints (optional).

- These are the constraints used during the optimization
(Optimization Objective & Constraints sheet). 5. Specify manipulated (varied) variables. - These are the variables that the optimization block will change to maximize/minimize the objective function (Optimization Vary sheet).

6. Specify bounds for manipulated (varied) variables. - These are the lower and upper bounds within which to vary the manipulated variable (Optimization Vary sheet).
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Introduction to Aspen Plus

Slide 299
©1997 AspenTech. All rights reserved.

Notes
1. The convergence of the optimization can be sensitive to the initial values of the manipulated variables.

2. It is best if the objective, the constraints, and the manipulated variables are in the range of 1 to 100. This can be accomplished by simply multiplying or dividing the function.
3. The optimization algorithm only finds local maxima and minima in the objective function. It is theoretically possible to obtain a different maximum/minimum in the objective function, in some cases, by starting at a different point in the solution space.
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Introduction to Aspen Plus

Slide 300
©1997 AspenTech. All rights reserved.

Notes (Cont.)
4. Equality constraints within an optimization are similar to design specifications. 5. If an optimization does not converge, run sensitivity studies with the same manipulated variables as the optimization, to ensure that the objective function is not discontinuous with respect to any of the manipulated variables. 6. Optimization blocks also have convergence blocks associated with them. Any general techniques used with convergence blocks can be used if the optimization does not converge.
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Introduction to Aspen Plus

Slide 301
©1997 AspenTech. All rights reserved.

Optimization Workshop
Objective: Optimize steam usage for a process.
The flowsheet shown below is part of a Dichloro-Methane solvent recovery system. The two flashes, TOWER1 and TOWER2, are run adiabatically at 19.7 and 18.7 psia respectively. The stream FEED contains 1400 lb/hr of Dichloro-Methane and 98600 lb/hr of water at 100oF and 24 psia. Set up the simulation as shown below, and minimize the total usage of steam in streams STEAM1 and STEAM2, both of which contain saturated steam at 200 psi. The maximum allowable concentration of Dichloro-Methane in the stream EFFLUENT from TOWER2 is 150 ppm (mass) to within a tolerance of a tenth of a ppm. Use the NRTL Property Method. Use bounds of 1000 lb/hr to 20,000 lb/hr for the flowrate of the two steam streams. Make sure stream flows are reported in mass flow and mass fraction units before running. Refer to the Notes slides for some hints on the previous page if there are problems converging the optimization.
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Introduction to Aspen Plus

Slide 302
©1997 AspenTech. All rights reserved.

Optimization Workshop (Cont.)
TOP1
STEAM1 TOWER1

FEED

TOP2 TOWER2

BOT1 STEAM2

EFFLUENT When finished, save as filename: OPT.BKP
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Introduction to Aspen Plus

Slide 303
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

RadFrac Convergence
Objective: Introduce the convergence algorithms and initialization strategies available in RadFrac

Aspen Plus References: Unit Operation Models, Chapter 4, Columns

Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

304

RadFrac Convergence Methods
RadFrac provides a variety of convergence methods for solving separation problems. Each convergence method represents a convergence algorithm and an initialization method. The following convergence methods are available:

• • • • • •
®

Standard (default) Petroleum / Wide-Boiling

Strongly non-ideal liquid
Azeotropic Cryogenic Custom
2010年1月4日星期一 Introduction to Aspen Plus Slide 305
©1997 AspenTech. All rights reserved.

Convergence Methods (continued)
Method Standard Algorithm Standard Initialization Standard

Petroleum / Wide-boiling
Strongly non-ideal liquid Azeotropic

Sum-Rates
Nonideal Newton

Standard
Standard Azeotropic

Cryogenic
Custom

Standard
select any

Cryogenic
select any

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Introduction to Aspen Plus

Slide 306
©1997 AspenTech. All rights reserved.

RadFrac Convergence Algorithms
RadFrac provides four convergence algorithms:

• • • •

Standard (with Absorber=Yes or No)

Sum-Rates
Nonideal Newton

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Introduction to Aspen Plus

Slide 307
©1997 AspenTech. All rights reserved.

Standard Algorithm
The Standard (default, Absorber=No) algorithm:

• • • •

Uses the original inside-out formulation Is effective and fast for most problems Solves design specifications in a middle loop

May have difficulties with extremely wide-boiling or highly non-ideal mixtures

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Introduction to Aspen Plus

Slide 308
©1997 AspenTech. All rights reserved.

Standard Algorithm (Continued)
The Standard algorithm with Absorber=Yes:

• • • • •

Uses a modified formulation similar to the classical sum-rates algorithm Applies to absorbers and strippers only Has fast convergence Solves design specifications in a middle loop May have difficulties with highly non-ideal mixtures

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Introduction to Aspen Plus

Slide 309
©1997 AspenTech. All rights reserved.

Sum-Rates Algorithm
The Sum-Rates algorithm:

• •

Uses a modified formulation similar to the classical sum-rates algorithm Solves design specifications simultaneously with the column-describing equations

•
•

Is effective and fast for wide boiling mixtures and problems with many design specifications
May have difficulties with highly non-ideal mixtures

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Introduction to Aspen Plus

Slide 310
©1997 AspenTech. All rights reserved.

Nonideal Algorithm
The Nonideal algorithm:

• • • •

Includes a composition dependency in the local physical property models Uses the continuation convergence method Solves design specifications in a middle loop Is effective for non-ideal problems

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Introduction to Aspen Plus

Slide 311
©1997 AspenTech. All rights reserved.

Newton Algorithm
The Newton algorithm:

• • •

Is a classic implementation of the Newton method

Solves all column-describing equations simultaneously
Uses the dogleg strategy of Powell to stabilize convergence

•
• •
®

Can solve design specifications simultaneously or in an outer loop
Handles non-ideality well, with excellent convergence in the vicinity of the solution Is recommended for azeotropic distillation columns
Introduction to Aspen Plus Slide 312
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Vapor-Liquid-Liquid Calculations
You can use the Standard, Newton and Nonideal algorithms for 3-phase Vapor-Liquid-Liquid systems. On the RadFrac Setup Configuration sheet, select Vapor-Liquid-Liquid in the Valid Phases field. Vapor-Liquid-Liquid calculations: • Handle column calculations involving two liquid phases rigorously • Handle decanters • Solve design specifications using: - Either the simultaneous (default) loop or the middle loop approach for the Newton algorithm - The middle loop approach for all other algorithms
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Introduction to Aspen Plus

Slide 313
©1997 AspenTech. All rights reserved.

Convergence Method Selection
For Vapor-Liquid systems, start with the Standard convergence method. If the Standard method fails: • Use the Petroleum / Wide Boiling method if the mixture is very wide-boiling. • Use the Custom method and change Absorber to Yes on the RadFrac Convergence Algorithm sheet, if the column is an absorber or a stripper. • Use the Strongly non-ideal liquid method if the mixture is highly non-ideal. • Use the Azeotropic method for azeotropic distillation problems with multiple solutions possible. The Azeotropic algorithm is also another alternative for highly non-ideal systems.
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Introduction to Aspen Plus

Slide 314
©1997 AspenTech. All rights reserved.

Convergence Method Selection (Continued)
For Vapor-Liquid-Liquid systems:

• •

Start by selecting Vapor-Liquid-Liquid in the Valid Phases field of the RadFrac Setup Configuration sheet and use the Standard convergence method. If the Standard method fails, try the Custom method with the Nonideal or the Newton algorithm.

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Introduction to Aspen Plus

Slide 315
©1997 AspenTech. All rights reserved.

RadFrac Initialization Method
Standard is the default Initialization method for RadFrac. This method:

•
• •

Performs flash calculations on composite feed to obtain average vapor and liquid compositions
Assumes a constant composition profile

Estimates temperature profiles based on bubble and dew point temperatures of composite feed

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Introduction to Aspen Plus

Slide 316
©1997 AspenTech. All rights reserved.

Specialized Initialization Methods
Four specialized Initialization methods are available. Use: Crude Chemical Azeotropic Cryogenic For: Wide boiling systems with multi-draw columns Narrow boiling chemical systems Azeotropic distillation columns Cryogenic applications

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Introduction to Aspen Plus

Slide 317
©1997 AspenTech. All rights reserved.

Estimates
RadFrac does not usually require estimates for temperature, flow and composition profiles.

RadFrac may require:

•

Temperature estimates as a first trial in case of convergence problems Liquid and/or vapor flow estimates for the separation of wide boiling mixtures. Composition estimates for highly non-ideal, extremely wide-boiling (for example, hydrogen-rich), azeotropic distillation or vapor-liquid-liquid systems.
Introduction to Aspen Plus Slide 318
©1997 AspenTech. All rights reserved.

•
•

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Composition Estimates
The following example illustrates the need for composition estimates in an extremely wide-boiling point system:

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Introduction to Aspen Plus

Slide 319
©1997 AspenTech. All rights reserved.

RadFrac Convergence Workshop
HCl column rating
Feed: Flow rate Temperature Pressure Column: 260000 lb/hr 135 F 170 psia Component Hydrogen-Chloride Vinyl-Chloride 1,2-diChloroethane Massfrac 0.195 0.335 0.470

Stages 33 + condenser + reboiler Pressure 168 psia (cond), 174 psia (reb) Estimated RR=0.7 D:F=1.0 (based on HCl), all vapor distillate Column diameter Trays Tray spacing Weir height Valve density Downcomer: 7 ft 66 float valve @ 50% efficiency, 2 flow passes 18 in 2 in 12 units/sqft Clearance 1.5 in Width 8.7 in (side), 7.1 in (center)

Trays:

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Introduction to Aspen Plus

Slide 320
©1997 AspenTech. All rights reserved.

RadFrac Convergence Workshop (Continued)
Calculation:

• •

Simulate the HCl column using RadFrac and use the Sum-Rates convergence method. Use the Peng-Robinson equation of state to represent the physical properties.

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Introduction to Aspen Plus

Slide 321
©1997 AspenTech. All rights reserved.

RadFrac Convergence Workshop (Continued)
Results:

• • • • • •

Plot liquid composition profiles for all components.

Plot the temperature profile.
What are the condenser and reboiler duties? Display component split fractions among products.

Which is the limiting stage with regard to jet flooding?
What stage has the maximum DC backup/tray spacing ratio?

•
®

What is the predicted pressure drop for the section?

2010年1月4日星期一

Introduction to Aspen Plus

Slide 322
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

External Fortran
Objectives: Learn how to use external Fortran which is an open and extensive customization capability

Aspen Plus References: • Reference Manual, Volume 6, User Models
Introduction to Aspen Plus
® ©1997 AspenTech. All rights reserved.

323

External Fortran Application Types
• User Operation
Units not represented by standard blocks

• Kinetic Models
Kinetic reactors or reactive distillation

• Property Models
Pure and mixture, activity models, KLL, user equations-of-state

• Unit Operation Customization
Reactor heat transfer, column hydraulics, LMTD correction

• Customized Reports
User-defined stream report, user block reports, Summary File Toolkit
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Introduction to Aspen Plus

Slide 324
©1997 AspenTech. All rights reserved.

Supporting Framework • • •
Physical Property Monitors
Easy access to physical properties calculated by Property Method assigned to block or flowsheet section.

System Variables
Simplifies interface, simulation control, and diagnostics

Utility Routines
Simplifies housekeeping, error reporting, user messages

•

Functions
Easy access to physical property parameters, PLEX data, simulation control variables

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Introduction to Aspen Plus

Slide 325
©1997 AspenTech. All rights reserved.

Thermodynamic Monitors •
General Phase Monitors
(VTHRM, VMTHRM, LTHRM, LTHRMY, STHRM, SMTHRM) • Multiple properties can be calculated at same time

• •

(more efficient for equations-of-state)

Properties are requested using flags, i.e. KH, KPHI Components must be packed

• • • • •
®

K Value (KVL and KLL)
Enthalpy (ENTHV, ENTHL, ENTHS) Volume (VOLV, VOLL, VOLS)

Fugacity (FUGV, FUGL, FUGS)
Ideal Gas (IDLGAS)
Introduction to Aspen Plus Slide 326
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Transport Monitors
Mixture Properties for Packed Components

•
• • •

Viscosity (VISCV, VISCL)
Thermal Conductivity (TCONV, TCONL, TCONS) Diffusion Coefficients (DIFCOV, DIFCOL) Surface Tension (SRFTNY)

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Introduction to Aspen Plus

Slide 327
©1997 AspenTech. All rights reserved.

System Variables • •
NHSTRY, NRPT, NTERM (Common User)
Fortran logical unit numbers I.e. Write(Nhstry, 10)

IPASS (Common User)
I.e. Suppress simulation error messages if IPASS GT 3

•

Common /PLEX/ B(1) Equivalence (B(1), IB(1))
I.e. B reference is used for real data IB reference is used for integer data such as pointers

•
®

NCC, NNCC (Common Ncomp)
Introduction to Aspen Plus Slide 328
©1997 AspenTech. All rights reserved.

2010年1月4日星期一

Stream Vectors
Dynamically dimensioned stream array
ie. DIMENSION SIN1(1) Component Mole Flows (1 to NCC, kmol/sec) Total Mole Flow (kmol/sec) Temperature (K) Pressure (N/m2) Mass Enthalpy (J/Kg) Vapor Fraction Liquid Fraction Mass Entropy (J/Kg-K) Mass Density (kg/m3) Molecular Weight (kg/kmol)
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Introduction to Aspen Plus

Slide 329
©1997 AspenTech. All rights reserved.

Utility Functions •
IFCMNC Returns Plex parameter offset to parameter data I.e. IMW= IFCMNC(„MW‟) KFORMC and KCCIDC Returns component index I.e. IN2= KFORMC(„N2‟) xN2mw= B(IMW+IN2)

•

•

IRRCHK Check error against diagnostic level for reporting
Introduction to Aspen Plus Slide 330
©1997 AspenTech. All rights reserved.

2010年1月4日星期一
®

Utility Routines •
Call Pack(Strmvec, Ncp, Pvec, Xvec, TFlow) • Converts stream vector to contain only components that are present. WRTTRM • Passes output text to the Control Panel or Terminal. • Used with Common MAXWRT.

•

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Introduction to Aspen Plus

Slide 331
©1997 AspenTech. All rights reserved.

Integrating External Fortran •
Use ASPCOMP to compile.

•
• •

All object files in working directory are automatically linked.
CMP and LD diagnostic files. DLOPT file can be used to list name and location of all object files.

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Introduction to Aspen Plus

Slide 332
©1997 AspenTech. All rights reserved.

Upgrading Fortran to Aspen Plus 10 • All user Fortran subroutines must be converted. • A conversion utility is delivered with Version 10
(AP9TO10)

• •

The conversion utility will convert both user Fortran subroutines and in-line Fortran code. In-line Fortran can only be converted from input files, not from backup or binary files.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 333
©1997 AspenTech. All rights reserved.

Reach Your

Potential

True

Vinyl Chloride Monomer (VCM) Workshop

Introduction to Aspen Plus
®

©1997 AspenTech. All rights reserved.

334

VCM Workshop
Objective: Set up a flowsheet of a VCM process using the tools learned in the course.
Vinyl chloride monomer (VCM) is produced through a high pressure, non-catalytic process involving the pyrolysis of 1,2-dichloroethane (EDC) according to the following reaction CH2Cl-CH2Cl HCl + CHCl=CH2

The cracking of EDC occurs at 500 C and 30 bar in a direct fired furnace. 1000 kmol/hr of pure EDC feed enters the reactor at 20 C and 30 bar. EDC conversion in the reactor is maintained at 55%. The hot gases from the reactor are subcooled by 10 degrees before fractionation. Two distillation columns are used for the purification of the VCM product. In the first column, anhydrous HCl is removed overhead and sent to the oxy chlorination unit. In the second column, VCM product is removed overhead and the bottoms stream containing unreacted EDC is recycled back to the furnace. Overheads from both columns are removed as saturated liquids. The HCL column is run at 25 bar and the VCM column is run at 8 bar. Use the RK-SOAVE Property Method.
2010年1月4日星期一
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Introduction to Aspen Plus

Slide 335
©1997 AspenTech. All rights reserved.

VCM Workshop (Cont.)
CH2Cl-CH2Cl
1000 kmol/hr EDC 20C 30 bar
FEED

HCl + CHCl=CH2
RadFrac Model Heater Model
COOLOUT COL1 VCMOUT CRACK HCLOUT

RStoic Model

RadFrac Model

REACTOUT

RECYCIN

Pump Model

500 C 30 bar EDC Conv. = 55%

QUENCH

10 deg C subcooling 0.5 bar pressure drop

VCMIN

COL2

15 stages

Reflux ratio = 1.082 Distillate to feed ratio = 0.354 Feed enters above stage 7 Column pressure = 25 bar

PUMP

30 bar outlet pressure
RECYCLE

10 stages Reflux ratio = 0.969 Distillate to feed ratio = 0.550 Feed enters above stage 6 Column pressure = 8 bar

Use RK-SOAVE property method
2010年1月4日星期一
®

When finished, save as filename: VCM.BKP
Introduction to Aspen Plus Slide 336
©1997 AspenTech. All rights reserved.

VCM Workshop (Cont.)
Part A: With the help of the process flow diagram on the previous page, set up a flowsheet to simulate the VCM process. What are the values of the following quantities? 1. Furnace heat duty ________ 2. Quench cooling duty ________ 3. Quench outlet temperature ________ 4. Condenser and Reboiler duties for COL2 ________ 5. Concentration of VCM in the product stream ________ Part B: The conversion of EDC to VCM in the furnace varies between 50% and 55%. Use the sensitivity analysis capability to generate plots of the furnace heat duty and quench cooling duty as a function of EDC conversion.

Part C:
Set up a Fortran block to execute at the end of the simulation. The Fortran block should print the combined reboiler duties of both distillation columns to the control panel.

2010年1月4日星期一
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Introduction to Aspen Plus

Slide 337
©1997 AspenTech. All rights reserved.


				
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