OPPORTUNITIES FOR FUEL CELLS AT WASTEWATER TREATMENT PLANTS

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OPPORTUNITIES FOR FUEL CELLS AT WASTEWATER
TREATMENT PLANTS
For presentation at the EPA Fuel Cell Workshop to
be held in Cincinnati, Ohio on June 26-27, 2001
William Hahn, P.E.Science Applications
International Corporation11251 Roger Bacon
DriveReston, VA 20190
For U.S. Environmental Protection AgencyOffice
of Wastewater Management401 M Street, S.
W.Washington, D.C. 20460
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Study Objectives

• Assess opportunities for use of fuel cell
  technologies in the wastewater treatment industry
• Determine potential market
• Evaluate 4 fuel cell technologies PAFC, PEM,
  MCFC, SOFC using benefit factors
• Identify best potential applications

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Carbon Fate and Availability in the Wastewater
Treatment Process
Population size 100,000 10 MDG
Influent
Effluent
2,850 lbs C
10,000 lbs C
500 lbs C
Aerobic Treatment
Solids Disposal
2,250 lbs C
1,100 lbs C
Sludge
3,300 lbs C
6,650 lbs C
Anaerobic Digestion
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Profile of WWTP Industry
16,042 WWTPs
Only 3,452 WWTPs use Anaerobic Digestion
Only 266 WWTPs use Digester Gas
Information from the 1996 Clean Water Needs
Survey
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Geographic Distribution of WWTPs Using Anaerobic
Digestion
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Geographic Distribution of WWTPs Using Digester
Gas
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Typical Digester Gas Compositions (Dry Basis)
Reference Trocciola, J.C. and Healy, H.C., U.S.
Environmental Protection Agency. (1995, March).
Demonstration of Fuel Cells to Recover Energy
form an Anaerobic Digester Gas- Phase 1.
Conceptual Design, Preliminary Costs, and
Evaluation Study.
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Potential Uses of Biogas

• On-site
• Heat for treatment processes
• Heat for space heating and cooling
• Back-up power
• Powering engines to drive equipment

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Case StudyPortland, Oregon
82 MGD facility WWTP generates 1,000,000 ft3 of
biogas per day System cost 1.3 million Reduces
annual electricity bill by 92,000 and eliminates
emergency generators, saving additional 150,000.
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Case Study Portland, Oregon
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Assessment of Fuel CellTechnologies
Phosphoric Acid Fuel Cells Proton Exchange
Membrane Fuel Cells Molten Carbamate Fuel
Cells Solid Oxide Fuel Cells
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List of Preliminary Benefit Factors
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Comparison of Benefit Factors for Fuel Cell
Technologies
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Fuel Cells at Wastewater Treatment Plants
Drivers Electric power demand Fuel and use
co-located Small size fits the industry Cogenerati
on is important Standby power is needed Low noise
and emissions External funding is available
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Fuel Cells at Wastewater Treatment Plants
Barriers Industry uncertainty about innovative
technology Purchased power is relatively
inexpensive Fuel conditioning for small cells may
be too complex Biogas often contains hydrogen
sulfide Limited number of facilities for large
scale fuel cell applications.