Learning Center
Plans & pricing Sign in
Sign Out

Switch Grass as a Fossil Fuel Supplement - The Nelson Institute


									Today’s Agenda
 Recap of Chariton Valley Biomass Project (Iowa)  Structure  Challenges  Lessons learned  How to Achieve Similar Success in Wisconsin  Biomass supply  Bio refinery  Bio-power plant

Alliant Energy’s Renewable Energy Portfolio

Chariton Valley Biomass Project
 Chariton Valley Resource Conservation and Development received Dept. of Energy grant in 1994  Approached Alliant Energy-Interstate Power and Light Co. about burning switch grass with pulverized coal in 1995

 Other partners include: USDA, National Renewable Energy Laboratory, Prairie Lands Bio-Products, Iowa Department of Natural Resources, Iowa State University, Iowa Farm Bureau Federation, Iowa Energy Center

Alliant Energy’s Role
 Designate Ottumwa Generating Station as project test site  Provide environmental management/support  Over 5,000 labor hours from IPL employees  Provide technical support to:  Develop processing facility design  Design/execute necessary modifications  Conduct test burns and compile data

Challenges for Alliant Energy
 OGS is base load plant  Boiler not designed to burn switch grass; could affect reliability  Co-fired fly ash might not meet Iowa DNR standards for road construction

The Role of Prairie Lands Biomass, LLC
 Identify and develop switch grass products and markets  Produce, harvest and deliver switch grass to satisfy demand  Evaluate environmental benefits of producing and using switch grass  Inform and educate the public about switch grass’ potential

First Test Burn
 November 30, 2000 – January 25, 2001  Burned 1,269 tons of switch grass (at rates up to 16.8 tons per hour)  Primary goals:  Identify effects of co-firing on boiler performance  Measure changes in emissions during co-firing  Gather information to improve the design of switch grasshandling equipment

Second Test Burn
 December 2003 (2 weeks)  Burned 781 tons of switch grass (at rates up to 8.9 tons per hour)  Improved switch grass-handling system was used  Primary goals:  Verify air emissions  Obtain large samples of co-fired fly ash for testing  Further analyze the technological feasibility of switch grass cofiring

Third Test Burn
 February – May 2006 (1,700 hours)  Burned more than 15,000 tons of switch grass  Primary goals:  Refine switch grass processing system  Secure certification of renewable energy credits through Environmental Resources Trust  Finalize steps necessary for commercialization

Switch Grass Processing Facility
 Construction of facility and technical refinement of processing system essential to achieve commercialization

How Does the Process Begin?

Removing Twine Prior to Processing

Preparing Switch Grass for the Boiler

How Switch Grass Enters the Boiler

Maintaining Co-Fired Fly Ash Certification
 Recognized national leader in coal-combustion product re-use  Annual sales: $3 million

Where is Chariton Valley Biomass Project Today?
 Moving toward commercialization of the process  Analysis of final test burn expected in May 2007  Initiate contracts for switch grass supply

Achieving Similar Success in Wisconsin
 What will it take?  Formation of a growers’ association  Change in CRP rules  Establish new policies  Guidance, financial incentives from USDA, others

Achieving Similar Success in Wisconsin
It will require: 1. Biomass materials supply 2. Bio-fuel refinery 3. Bio-power plant To deliver these functions: 1. Biomass to bio-fuel refinery 2. Biomass to bio-fuels 3. Bio-fuels to electricity

Alliant Energy is committed to developing bio-power at Nelson Dewey

Bio-Based Materials Under Consideration
 WPL initial conceptual design  “Woody” biomass  Switch grass  WPL currently investigating potential use of these materials:  Other “grasses”  Hay  Straw  Corn stover  Wood forest residues  Other wood varieties (Poplar, Willow, Bark)

Co-Firing Switch Grass at Nelson Dewey
How many tons of switch grass would be needed to supply Unit 3?

 Manufacturer design for 10% biomass  100,000 tons per year
 Unit 3 bio-power target at 20% or more  >200,000 tons per year

Potential Switch Grass Production
How many acres of switch grass will be needed?  Manufacturer design for 10% biomass  33,000 acres per year @ 3 ton per acre yield  25,000 acres per year @ 4 ton per acre yield  Unit 3 bio-power target at 20% or more  >66,000 acres per year @ 3 ton per acre yield  >50,000 acres per year @ 4 ton per acre yield

Nelson Dewey Generating Station Cassville, Wis.
 Unit # 1  100 MW  Built in 1959  Unit # 2  100 MW  Built in 1962

Nelson Dewey Generating Station Cassville, Wis. Tomorrow
 Unit # 1  100 MW  Built in 1959 Unit # 2  100 MW  Built in 1962 Unit # 3  300 MW in 2012  Bio-power capable  Bio-fuel permitted



Hurdles to Overcome: Bio-Based Fuel Supplies
Biomass Materials SUPPLY Functions

 Growing
 Harvesting

 Storage
 Biomass material quality control  Transportation to processor

Hurdles to Overcome: Bio-Based Fuel Supplies
Biomass Fuel REFINERY Functions

 Aggregation
 Processing into fuels  Bio-fuel quality control  Biomass fuel storage  Delivery

Developing Bio-Power at Nelson Dewey
Unit 3 bio-power design requirements based on:

 Identification of regional biomass material types
 Specific biomass material characteristics  Heat content  Moisture level  Ash content  Specific biomass material chemistry  Alkali levels  Chloride levels

Developing Bio-Power at Nelson Dewey
Biomass fuel USE design issues to resolve:

 Reduced to power output levels
 Reduced combustion efficiency

 Alkali and chloride impacts  Increased boiler fouling  Increased boiler tube corrosion  Reduced availability

Developing Bio-Power at Nelson Dewey
Alliant Energy targets for Unit 3:

 Expand manufacturer designs for up to 20% or more biomass
 Expand bio-fuels beyond wood and switch grass

 Increase bio-fuels types and percent in air permit  2007, if possible  In the future, if architect and boiler manufacturer require time
 Design of bio-fuel systems with architect and manufacturer

Developing Bio-Power at Nelson Dewey
For newer and larger 300 MW circulating fluidized bed units:

 Manufacturer designs are for up to 10% biomass capability
 Unit 3 air permit applications now include:  10% Woody biomass  10% Switch grass  Unit 3 design includes area designated for bio-fuel handling  Equipment design will occur after selection of:  Architect / Engineer  Boiler manufacturer

Achieving Similar Success in Wisconsin
It will require: 1. Bio-power plant 2. Bio-fuel refinery 3. Biomass materials supply

Bio-power success requires local leadership to supply biomass materials and bio-fuel refining

Existing Bio-Fuels Advantages
 Water quality  Soil quality  Habitat improvement  Local economic opportunities

Additional Air Quality Benefits of Co-Firing Switch Grass
 Lower fuel sulfur levels  Equal or lower fuel nitrogen levels  Equal or lower fuel ash levels  Reduced carbon footprint

Nelson Dewey Air Permit Co-Firing 10 % Switch Grass or Wood
Nelson Dewey 3 Air Permit Application Specifying 10% biomass identified as: Switch grass or Wood

For More Information…
   Kim Zuhlke, Vice President-New Energy Resources or 608.458.5747  Kirby Letheby, Team Lead-New Generation or 608.458.3276


To top