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Life-Cycle AnalysisAssessment _LCA_ - The Systems Realization

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					Life-Cycle Analysis/Assessment
             (LCA)




                     Georgia Institute of Technology
                     Systems Realization Laboratory
                      Life Cycle Analysis

• Life-cycle analysis (LCA) is a method in which the
  energy and raw material consumption, different types
  of emissions and other important factors related to a
  specific product are being measured, analyzed and
  summoned over the products entire life cycle from an
  environmental point of view.
   – Life-Cycle Analysis attempts to measure the “cradle to grave”
     impact on the ecosystem.

• LCAs started in the early 1970s, initially to investigate
  the energy requirements for different processes.
• Emissions and raw materials were added later.
• LCAs are the most comprehensive approach to
  assessing environmental impact.
                                                  Georgia Institute of Technology
                                                  Systems Realization Laboratory
                         LCA Method(s)

• Initially, numerous variants of LCA “methods” were
  developed/investigated, but today there is consensus that
  there is only one basic method with a large number of
  variants
• Over 30 LCA software packages have been developed:
   – SimaPro (NL), LCAIT-LCA (CH), PEMS (UK), IDEmat (NL), TEA (F), ...
• The scientific debate is held under the umbrella of the
  Society of Environmental Toxicology and Chemistry
  (SETAC), an international platform for toxicologists.
• SETAC has published the Code of Practice, a widely
  accepted series of guidelines and definitions.


                                               Georgia Institute of Technology
                                               Systems Realization Laboratory
                            LCA Steps

• Generally, a LCA consists of four main activities :

1) Goal definition: the basis and scope of the evaluation are defined.
2) Inventory Analysis: create a process tree in which all processes from
   raw material extraction through waste water treatment are mapped out
   and connected, mass and energy balances are closed, and emissions
   and raw material and energy consumptions are accounted.
3) Impact Assessment: Environmental loadings identified in the
   inventory are translated into environmental effects. The
   environmental effects are grouped and weighted.
4) Improvement Assessment: Areas for imporvement are identified.




                                                Georgia Institute of Technology
                                                Systems Realization Laboratory
       LCA Step 1 - Goal Definition and Scope

• It is important to establish beforehand what purpose
  the model is to serve, what one wishes to study, what
  depth and degree of accuracy are required, and what
  will ultimately become the decision criteria.

• In addition, the system boundaries - for both time and
  place - should be determined.

• Thus, pay special attention to:
   – Basis for evaluation (what and why)
   – Temporal boundaries (time scale)
   – Spatial boundaries (geographic)

                                           Georgia Institute of Technology
                                           Systems Realization Laboratory
            LCA Step 2 - Inventory Analysis

• This means that the inputs and outputs of all life-cycle
  processes have to be determined in terms of material and
  energy.
• Start with making a process tree or a flow-chart
  classifying the events in a product’s life-cycle which are
  to be considered in the LCA, plus their interrelations.
• Next, start collecting the relevant data for each event:
  the emissions from each process and the resources (back
  to raw materials) used.
• Establish (correct) material and energy balance(s) for
  each process stage and event.



                                         Georgia Institute of Technology
                                         Systems Realization Laboratory
Simplified Process Tree for a Coffee Machine’s Life-Cycle

      coffee     paper             poly-           aluminium     sheet s teel   glas
      bean                         styrene

      roasting   filter pro-       injection       extrusion     stamping       forming
                 duction           moulding                      forming


                                                   as sembly
                                                   + transport

                                                   packaging
                                                                                electricity

                                                     us e
                                                                                 w ater

                               disposal of         disposal in
                               filters + c offee   municipal
                               in org. w as te     w aste

                                                                  Georgia Institute of Technology
                                                                  Systems Realization Laboratory
         Process Tree with Amounts and Assumptions
            7.3 kg            1 kg           0.1 kg         0.3 kg        0.4 kg
coffee                      poly-
           paper                            aluminium     sheet s teel   glas
bean                        styrene


roasting   filter pro-      injection       extrusion     stamping       forming
           duction          moulding                      forming


                                            as sembly
                                            + transport
                                                                          375 kWh
                                            packaging
                                                                         electricity

                                              us e
                                                                          w ater


                         disposal of        disposal in
                         filters + coffee   municipal             White boxes are not included in
                         in org. w as te    w aste
                                                                   assessment/inventory


                                                                         Georgia Institute of Technology
                                                                         Systems Realization Laboratory
                    Single Stage Flow Diagram

• The following diagram contains inputs and outputs to be
  quantified in a single stage or unit operation (see EPA
  Life-Cycle Design Guidance Manual, EPA Report no.
  EPA/600/R-92/226, page 104)
                               Process Materials, Reagents,
                               Solvents & Catalysts (including
                               reuse & recycle from another stage)
                    Energy


   Product Material
   Inputs (including
   reuse & recycle from                                 Reuse/Recycle
   another stage)            Single Stage or Unit
                                 Operation
                                                        Primary Product

                                                        Useful Co-product
                                  Fugitive &
                                  Untreated
                                  Waste             Waste
          Reuse/Recycle

                                                                Georgia Institute of Technology
                                                                Systems Realization Laboratory
             Problems with Inventory Analysis

• The inventory phase usually takes a great deal of time
  and effort and mistakes are easily made.

• There exists published data on impacts of different
  materials such as plastics, aluminum, steel, paper, etc.
   – However, the data is often inconsistent and not directly applicable due
     to different goals and scope.
   – It is expected that both the quantity and quality of data will improve
     in the future.


• Frequently made mistakes:
   – Mass and energy balances are not correct and defy laws of thermo-
     dynamics
   – Results are generalized improperly.

                                                    Georgia Institute of Technology
                                                    Systems Realization Laboratory
         LCA Step 3 - Impact Assessment

• The inventory analysis provides a listing of
  environmental impact in terms of energy and material
  consumption and emission.
• The impact assessment focuses on characterizing the
  type and severity of environmental impact more
  specifically.
• There are a number of different ways to assess the
  impact, but it is recommended to perform a
  normalization and valuation procedure.




                                     Georgia Institute of Technology
                                     Systems Realization Laboratory
                          Impacts Classification

• Impacts are classified into environmental effects/damages.
   – The example below is in accordance with the Dutch LCA manual.
       Impact                         Effect
                                     depletion of biotic resources
       copper
                                     depletion of abiotic resources
       CO2
       CFC                           greenhouse effect
       SO2
       NOx                           ozone layer depletion
       phosphorous                   acidification
       volatile organic
       compounds                     eutrophication
       (VOCs)
       heavy metals                 (summer) smog
       PCB
       pesticides                   human toxicity
       styrene
                                    eco-toxicity

                                    odour

                                                         Georgia Institute of Technology
                                                         Systems Realization Laboratory
            Plastic versus Paper Bag Classification
                                                         Classificat ion / Charact erisat ion

    10 0%
     90 %
     80 %
     70 %
     60 %                                                                                                                       Paper bag
     50 %                                                                                                                       LDPE bag
     40 %
     30 %
     20 %
     10 %
      0%



               effect
            greenho use     deplet ion                                                                                      pest icides
                          ozone layer    acidification                  heavy metals carcinogens wint er smog summer smog
                                                         eutrop hicat ion


• The paper bag causes more winter smog and acidification, but scores
  better on the other environmental effects.
• The classification does not reveal which is the better bag. What is
  missing is the mutual weighting of the effects.
                                                                                                Georgia Institute of Technology
                                                                                                Systems Realization Laboratory
     A Single Figure for Environmental Impact

• A single figure is needed for comparison purposes

• Several methods exists, but it is still a controversial
  issue and no singular widely accepted method exists.

• Three well-documened and used methods are:
   – The Eco-Points method
   – The Environmental Priority System
   – The Eco-Indicator




                                         Georgia Institute of Technology
                                         Systems Realization Laboratory
                        Eco-Points Method

• The eco-points method was developed in Switzerland and is
  based on the use of national government policy objectives.
• Environmental impacts are evaluated directly and there is
  no classification step.
• The evaluation principle is the distance to target principle,
  or the difference between the total impact in a specific area
  and the target value.
   – The target values in the original Ecopunkten method were derived from
     target values of the Swiss government.
   – A Dutch variant has been developed on the basis of the Dutch policy
     objectives.
• The use of policy objectives is controversial given that a
  policy does not express the true seriousness of a problem.
   – Various political, economic, and social considerations also play a role when
     formulating these objectives.
                                                    Georgia Institute of Technology
                                                    Systems Realization Laboratory
           The Eco-Points Evaluation Method

• A low number of eco-points is preferred.

 Impacts    Normalization          Evaluation                  Result
 In:        1 / target value   current / target value
 energy


 Out:       1 / target value   current / target value
 CO2                                                            Eco-
            1 / target value   current / target value           points
 SO2
            1 / target value   current / target value
 lead
 CFC        1 / target value   current / target value
 waste      1 / target value   current / target value

                                             Georgia Institute of Technology
                                             Systems Realization Laboratory
                 Eco-Points Method (cont.)

• The Eco-Points methods has been accepted as a useful
  instrument, even though objections can be raised against
  using politically established target levels.
   – The lack of a classification step is also regarded as a disadvantage - only
     a very limited number of impacts can be evaluated.


• Eco-points method is widely used in Switzerland and
  Germany.
   – It is also used in Norway, the United Kingdom and The Netherlands.
   – Since 1993, it has been included in the SimaPro software.


• The Eco-Points method is notsi much an environmental
  indicator as an indicator “in conformity with policy”

                                                   Georgia Institute of Technology
                                                   Systems Realization Laboratory
     The Environmental Priority System (EPS)

• The EPS system was used first for Volvo in Sweden.
• It is not based on governmental policy, but on
  estimated financial consequences of environmental
  problems.
• It attempts to translate environmental impact into a
  sort of social expenditure.
   – The first step is to establish the damage caused to a number of
     “safeguard objects” - objects that a community considers valuable.
   – The next step is to identify how much the community is prepared to
     pay for these things, i.e., the social costs of the safeguard objects are
     established.
   – The resulting costs are added up to a single figure.
• The EPS system includes neither classification or
  normalization.
                                                     Georgia Institute of Technology
                                                     Systems Realization Laboratory
             The EPS Evaluation Method




Impacts   Safeguard objects   Evaluation                  Result
In:         stocks
oil                           future costs for
zinc                          extraction
            production

                                                          value in
Out:        health            direct losses
                                                          ECU
CO2
SO2        biodiversity       willingness to
lead                          pay

CFC        aesthetics

                                        Georgia Institute of Technology
                                        Systems Realization Laboratory
                          The Eco-Indicator

• The Eco-Indicator was developed in a joint project carried
  out by companies, research institutes and the Dutch
  government.
• The aim was to develop an easy to use tool for product
  designers and the main outcome was a list of 100 indicators
  for te most significant materials and processes.
   – By using these indicators a designer can easily make combinations and carry
     out his/her own LCA. No outside expert or software are needed.
• Indicators have been drawn up for all life-cycle phases
   – the production of materials such as steel, aluminum, thermo-plastics, paper,
     glass
   – production processes, such as injection molding, rolling, turning, welding
   – transport by road, rail, and sea
   – energy generating processes
   – waste processing processes, such as incineration, dumping, recycling.
                                                     Georgia Institute of Technology
                                                     Systems Realization Laboratory
                        Eco-Indicator (cont.)

• The evaluation method for calculating the Eco-Indicators
  strongly focuses on the effects of emissions on the ecosystem.
• For the valuation, the distance to target principle is used,
  but the targets are based on scientific data on environmental
  damage and not on policy statements.
• The targets values are related to three types of
  environmental damage:
   – deterioration of ecosystems (a target level has been chosen at which “only”
     5% ecosystem degradation will still occur over several decades)
   – deterioriation of human health (this refers in particular to winter and
     summer smog and the acceptable level set is that smog periods should hardly
     ever occur again)
   – human deaths (the level chosen as acceptable is 1 fatality per million
     inhabitants per year)


                                                    Georgia Institute of Technology
                                                    Systems Realization Laboratory
             Eco-Indicator Evaluation Method

• Normalization is performed, but excluded in this
  figure for the sake of simplification.

    Impact        Effect          Damage       Valuation         Result
              Ozone layer depl.
    CFC
    Pb        Heavy metals
    Cd        Carcinogenics       Fatalities
    PAH       Summer smog
    Dust                          Health       Subjective
              Winter smog                      damage          Eco-indicator
    VOC                           impairment                      value
    DDT       Pesticides                       assessment
    CO2                           Ecosystem
             Greenhouse effect    impairment
    SO2
    NO        Acidification
       x
    P         Eutrophication




                                                            Georgia Institute of Technology
                                                            Systems Realization Laboratory
            Weighting Factors Used in Eco-Indicator

• Setting equivalents for these damage levels is a subjective
  choice.
   – The current choice (see below) came about after consultation with various
     experts and a comparison with other systems.

     Env i ro nmental          Wei g hti ng   Cri teri o n
     effect                    facto r
     Greenhouse effect             2.5        0.1C rise every 10 years, 5% ecosystem degradation
     Ozone layer depletion      100           Probability of 1 fatality per year per million inhabitants
     Acidification               10           5% ecosystem degradation
     Eutrophication                5          Rivers and lakes, degradation of an unknown number of
                                              aquatic ecosystems (5% degradation)
     Summer smog                  2.5         Occurrence of smog periods, health complaints, particularly
                                              amongst asthma patients and the elderly, prevention of
                                              agricultural damage
     Winter smog                  5           Occurrence of smog periods, health complaints, particularly
                                              amongst asthma patients and the elderly
     Pesticides                  25           5% ecosystem degradation
     Airborne heavy metals        5           Lead content in children’s blood, reduced life expectancy and
                                              learning performance in an unknown number of people
     Waterborne heavy metals      5           Cadmium content in rivers, ultimately also impacts on people
                                              (see airborne)
     Carcinogenic substances     10           Probability of 1 fatality per year per million people




                                                                                          Georgia Institute of Technology
                                                                                          Systems Realization Laboratory
                          Some Comments

• The preceding table reveals that
   – High priority must be given to limiting substances causing ozone layer
     damage and the use of pesticides. The latter is becoming a very serious
     problem in The Netherlands in particular.
   – Furthermore, a great deal of consideration must be given to the
     diffusion of acidifying and carcinogenic substances.
• A number of effects that are generally regarded as
  environmental problems have not been included:
   – Toxic substances that are only a problem in the workplace.
   – Exhaustion (depletion) of raw materials.
   – Waste.
• As a result of these differences the Eco-indicator can be
  seen as an indicator of emissions.
• Raw materials depletion and the use of space by waste
  must be evaluated separately at present.
                                                     Georgia Institute of Technology
                                                     Systems Realization Laboratory
     Toxic Substances in Workplace vs Nature

• Many substances are only harmful if they occur above
  a certain concentration. Such harmful concentrations
  can occur relatively easily in the workplace, while the
  concentration in the outside atmosphere often remains
  very low and well below the damage threshold due to
  dilution and natural decomposition processes.
• Only substances that actually occur in harmful
  concentrations are included in the Eco-indicator, while
  the rest are disregarded. This means that a product
  with a low Eco-indicator score can still cause poor
  working conditions because substances are released
  that are harmful locally.


                                      Georgia Institute of Technology
                                      Systems Realization Laboratory
             Exhaustion of Raw Materials

• If a product made of very rare raw materials is used
  this rarity is not expressed in the indicator; after all,
  the fact that a substance is rare does not cause any
  damage to health.
• The emissions arising from extraction of the raw
  materials are included and are usually extensive
  because ever lower-grade ores have to be used.
• Incidentally, the term “exhaustion” is very difficult to
  define. Alternatives are available for most raw
  materials, and recycling could enable raw materials to
  remain in circulation for much longer. In fact minerals
  never disappear from the Earth; at worst they are
  diffused in an unfortunate manner.
                                        Georgia Institute of Technology
                                        Systems Realization Laboratory
                         Waste

• The fact that waste occupies space is not particularly
  important in environmental terms because the amount
  of ecosystem lost to the mountains of waste is relatively
  small compared with the damage to ecosystems
  caused, for example, by acidification.
• However, the substances released by waste (heavy
  metals, or CO2 on incineration) are very important.
  These latter effects are included in the indicator
• The quantity of waste in itself is not part of the
  assessment process.




                                        Georgia Institute of Technology
                                        Systems Realization Laboratory
        LCA Step 4 - Improvement Assessment

• The final step in Life-Cycle Analysis is to identify areas
  for improvement.

• Consult the original goal definition for the purpose of the
  analysis and the target group.

• Life-cycle areas/processes/events with large impacts (i.e.,
  high numerical values) are clearly the most obvious
  candidates
• However, pay attention to the resources required and risk
  involved when selecting areas for improvement.
   – Good areas of improvement are those where large improvements can be
     made with minimal (corporate) resource expenditure and low risk.
                                                Georgia Institute of Technology
                                                Systems Realization Laboratory
                       LCA usage

In principle, LCAs could be used:
• in the design process to determine which of several
  designs may leave a smaller “footprint on the
  environment”, or
• after the fact to identify environmentally preferred
  products in government procurement or eco-labeling
  programs.

• Also, the study of reference or benchmark LCAs
  provides insight into the main causes of the
  environmental impact of a certain kind of product and
  design priorities and product design guidelines can be
  established based on the LCA data.
                                       Georgia Institute of Technology
                                       Systems Realization Laboratory
              Recognized Problems with LCA

• The major disadvantage of quantitative LCAs is their
  complexity and effort required
• Designers and manufacturing engineers find it almost
  impossible to practically work with LCAs because of
   – the consistent lack of solid data about all aspects of a products life cycle,
   – the nearly infinite amount of decisions to make and data to deal with,
   – the lack of standardization resulting in numerous conversions and
     interpretations,
   – the lack of a standard evaluation scheme caused by and resulting in
     different views on what is environmentally correct,
   – the approach is currently only suitable for design analysis / evaluation
     rather than design synthesis. LCAs are "static" and only deal with a
     snapshot of material and energy inputs and outputs in a dynamic system.



                                                       Georgia Institute of Technology
                                                       Systems Realization Laboratory
              Future Directions According to
            US Office of Techology Assessment

 In general:
 • Less information will probably be required.

 • LCAs will have to be streamlined to focus on a few critical dimensions of
   a product's environmental impact, rather than all dimensions.

Difference in usage:
    – For designers, the inventory does not need to be exhaustive to be
      useful.
    – For eco-labeling, the inventory should be rigorous, easily verifiable
      and periodically updated. Even so, at best, the inventory will clarify
      environmental tradeoffs, rather than provide definite conclusions.

  Software tools are becoming available, but underlying databases differ.
  For example, consider different opinions about "green" in the US and Europe.

                                                       Georgia Institute of Technology
                                                       Systems Realization Laboratory
                      Closing Remarks

• It is not the product, but the life-cycle of the product
  that determines its environmental impact.
• Even if the life-cycle is mapped out, there still exist
  many uncertainties as to the environmental impact of
  the processes involved. There is still an immense lack
  of reliable data.
   – Also consider uncertainties caused by customer behavior and
     (unknown) future process technologies.
• Knowledge about environmental systems is often
  highly uncertain.
• The LCA is generally a compromise between
  practicality and completeness

                                                Georgia Institute of Technology
                                                Systems Realization Laboratory

				
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