H 2 Technology and Policy: Fuel Cells as an Alternative Energy Source John McLees 9/27/05 ChE 384 Dr. Edgar

Government Policy For Alternative Energy Sources Clean Air Act Amendments (1990) Clean Air Act Amendments (1990) Reduction of tailpipe emissions of air pollutants Reduction of tailpipe emissions of air pollutants National Energy Policy Act of 1992 National Energy Policy Act of 1992 Replace up to 30% petroleum fuel by alternative energy sources by 2010 Replace up to 30% petroleum fuel by alternative energy sources by 2010 Mandates use of alternative energy sources by federal, state, and fuel provider fleets Mandates use of alternative energy sources by federal, state, and fuel provider fleets Alternative Fuels Initiative (1998) Alternative Fuels Initiative (1998) Field testing, demonstration, and assistance in revenue service for buses powered by alternative energy sources Field testing, demonstration, and assistance in revenue service for buses powered by alternative energy sources

Introduction to Fuel Cells Combustion engines use fuel to expand gases to create energy Combustion engines use fuel to expand gases to create energy Batteries: Electrical energy from chemical reaction Batteries: Electrical energy from chemical reaction Fuel cells are more efficient energy conversion devices Fuel cells are more efficient energy conversion devices 2H 2 + O 2 →2H 2 O + Electricity 2H 2 + O 2 →2H 2 O + Electricity Classified by electrolyte Classified by electrolyte

Types of Fuel Cells Proton Exchange Membrane Fuel Cell (PEMFC) Proton Exchange Membrane Fuel Cell (PEMFC) Alkaline fuel cell (AFC) Alkaline fuel cell (AFC) Requires high purity H 2 due to contamination issues Requires high purity H 2 due to contamination issues Used in space program since 1960’s Used in space program since 1960’s Solid oxide fuel cell (SOFC) Solid oxide fuel cell (SOFC) Large scale power plants (T = C) Large scale power plants (T = C) Steam production leads to improved efficiency Steam production leads to improved efficiency Molten carbonate fuel cell (MCFC) Molten carbonate fuel cell (MCFC) Large scale power plants (T = C) Large scale power plants (T = C) Less expensive than SOFC Less expensive than SOFC Phosphoric acid fuel cell (PAFC) Phosphoric acid fuel cell (PAFC) Small power plants Small power plants Long warm-up time makes it poor choice for automobiles Long warm-up time makes it poor choice for automobiles

Proton Exchange Membrane Fuel Cell 2H 2 →4H + + 4e- O 2 + 4H + + 4e - →2H 2 O

Benefits of the PEMFC Low operating temperature = 80 0 C Low operating temperature = 80 0 C Improved power density Improved power density 1990 – 3 kW 1990 – 3 kW 1997 – 50 kW 1997 – 50 kW Eventually used to power cars, buses, and possibly homes Eventually used to power cars, buses, and possibly homes

Fuel Cell Powered Cars Pollution reduction is key Pollution reduction is key Fuel cell plus methanol reformer Fuel cell plus methanol reformer Overall car efficiency Overall car efficiency Gasoline: 20% Gasoline: 20% Battery: 26% Battery: 26% PEMFC: 24-32% PEMFC: 24-32% Fuel cell buses currently operational in some cities Fuel cell buses currently operational in some cities Fuel cell-powered vehicles on the horizon Fuel cell-powered vehicles on the horizon Ford Company: 1 st H 2 fuel cell powered car at Detroit Auto Show Ford Company: 1 st H 2 fuel cell powered car at Detroit Auto Show Jeep Commander: methanol fuel reduces emissions to 90% of gasoline powered cars Jeep Commander: methanol fuel reduces emissions to 90% of gasoline powered cars

Disadvantages of Fuel Cells H 2 storage problems H 2 storage problems Use hydrocarbon reformers to produce H 2 Use hydrocarbon reformers to produce H 2 Produces other gases + heat Produces other gases + heat Convenience/practicality Convenience/practicality Filling station locations Filling station locations Safety concerns Safety concerns Cost Cost

Cost of Hydrogen U.S. Dept. of Energy’s Hydrogen, Fuel Cells, and Infrastructure Technologies Program has the following goals: U.S. Dept. of Energy’s Hydrogen, Fuel Cells, and Infrastructure Technologies Program has the following goals: By 2005, technology will be available to produce H 2 at $3.00/gasoline equivalent By 2005, technology will be available to produce H 2 at $3.00/gasoline equivalent By 2010, price should go down to $1.50 with increased technology By 2010, price should go down to $1.50 with increased technology Even $3.00/gallon is very attractive because FCVs are 2-3 times more efficient than ICE powered vehicles. Even $3.00/gallon is very attractive because FCVs are 2-3 times more efficient than ICE powered vehicles. Could potentially be less than $1/gallon if all goals are met Could potentially be less than $1/gallon if all goals are met

Conclusions Motivation for alternative energy sources Motivation for alternative energy sources Many types of fuel cells for specific applications Many types of fuel cells for specific applications Fuel cells’ efficiency and practicality increasing with technology Fuel cells’ efficiency and practicality increasing with technology H 2 shown to be safe and potentially cost- effective alternative to gasoline H 2 shown to be safe and potentially cost- effective alternative to gasoline

References U.S. Department of Energy Hydrogen, Fuel Cells, and Technologies Infrastructure Program U.S. Department of Energy Hydrogen, Fuel Cells, and Technologies Infrastructure Program Fuel Cells 2000 Fuel Cells How Fuel Cells Work How Fuel Cells Work

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