Fuel Cell Benefits and Obstacles to the Success of FCs and the Development of a Hydrogen-Based Economy
Chapter 5 Fuel Cell • Introduction • Historical Notes • Types of Fuel Cells • Fuel Cell Electrochemistry • Advantages of Fuel Cells • Applications of Fuel Cells • Advanced Hydrogen Production Technologies • Advanced Hydrogen Transport and Storage Technologies
5-1 IntroductionWhat is a Fuel Cell • A fuel cell → an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product.
5-2 Historical NotesFinally Coming of Age • In 1839, Sir William Grove reasoned that it should be possible to react hydrogen with oxygen to generate electricity. • In 1889, fuel cell was coined by Ludwig Mond and Charles Langer, who attempted to build the first practical device using air and coal gas.
Sir William Grove (1811-1896) “I cannot but regard the experiment as an important one…” William Grove writing to Michael Faraday, October 22, 1842
5-2 Historical Notes Finally Coming of Age • In early 20th Century, fuel cells were forgot • A lack of understanding of materials and electrode kinetics. • Internal combustion engine was developed. • Petroleum was discovered and rapidly exploited.
5-2 Historical NotesFinally of Coming Age • In 1932, the first successful fuel cell device was built by engineer Francis Bacon. • He improved on the expensive platinum catalysts employed by Mond and Langer with a hydrogen-oxygen cell using a less corrosive alkaline electrolyte and inexpensive nickel electrodes.
In the 1950s Bacon successfully produced the first practical (alkaline) FC. Francis T. Bacon (1904-1992)
5-2 Historical NotesFinally of Coming Age • Until 1959, Bacon and his coworkers were able to demonstrate a practical five-kilowatt system capable of powering a welding machine. • In October of that same year, Harry Karl Ihrig of Allis-Chalmers Manufacturing Company demonstrated his famous 20-horsepower fuel cell-powered tractor.
5-2 Historical NotesFinally of Coming Age • In the late of 1950s, fuel cells were noticed • NASA began to search some electricity generator for space mission. • Nuclear reactors as too risky, batteries as too heavy and short live, and solar power as cumbersome, NASA turned to fuel cells.
In the 1960s, NASA demonstrated some of their potential applications in providing power during space flight.
5-2 Historical NotesFinally of Coming Age • In 1960s, fuel cells would be the panacea to the world energy problem. The some qualities that make fuel cells idea for space exploration were considered. (ex. Small size, high efficiency, low emission.) • Nearly 30 years US$1 billion in research have been devote to address the barriers to the use of fuel cells for stationary application.
5-2 Historical NotesFinally of Coming Age • Fortunately • A number of manufacturers have supported numerous demonstration initiatives and ongoing research and development into stationary application. • Phosphoric acid fuel cells is being offered commercially, and more advanced designs, such as carbonate fuel cells and solid oxide fuel cells, are the focus of major electric technologies. • Full-sized (commercial) cells and full-height stacks have been successfully demonstrated for the carbonate fuel cell design.
5-2 Historical NotesFinally of Coming Age • It has taken more than 150 years to develop the basic science and to realize the necessary materials improvement for fuel cells to become a commercial reality. The fuel cell is finally coming of age!!
Then industry began to recognize the commercial potential of fuel cells. • But, due to technical barriers and high investment costs, fuel cells were not economically competitive with existing energy technologies.
Not anymore so! • Polymer Electrolyte Membrane Fuel Cells (PEMFCs; or Proton Exchange Membrane FCs) have become a ‘mature’ technology. • Well, there still is much work that needs to be done to optimize the FC system. • But hey, the gasoline IC engine is nearly 120 years old and still being improved.
Transportation • The California Low Emission Vehicle Program requires that beginning in 2003, 10% of passenger cars delivered for sale in CA from medium or large sized manufactures must be Zero Emission Vehicles (ZEVs).
Honda FCX Honda FCX specificationsVehicle Length: 4165 mm Width: 1760 mm Height: 1645 mm Maximum Speed: 93 mph (150km/h) Driving Range: 220 miles (355km) Seating Capacity: 4 adults First fuel cell vehicle in the world to receive government certification (American Honda Motor Co., Inc., 7/24/2002).
Motor Maximum Power Output: 80hp (60kW) Maximum Drive Torque: 201lb-ft (272Nm) Motor Type: AC synchronous Fuel Cell Stack Stack Type: PEFC (proton exchange membrane type - Ballard) Power Output: 78kW Power storage Honda Ultra Capacitor Fuel Type: Compressed gaseous hydrogen Storage Method: High-pressure hydrogen storage tank (5,000 psi) Fuel Capacity: 156.6 liter
NECAR 5 • 2001 prototype FC automobile by DaimlerChrysler.
Drives and feels like a “normal” car. • Top speed > 150 km/hr, with a power output 0f 75 kW (100 hp). • Combines the low emission levels, the quietness and the smoothness associated with EVs, while delivering a performance similar to that of an automobile with an IC engine.
Fuel Cell Bus • In March 1998, Chicago became the first city in the world to put pollution-free, hydrogen fuel cell powered buses in their public transit system.
The PEM fuel cells were provided by Ballard Power Systems. • Air Products & Chemicals supplies the liquid hydrogen, which is converted to gas for bus use. • The pilot program began in December 1997 at the Chicago Transit Authority, which will receive royalties for every bus sold by Ballard, up to US$4 million.
Back Fuel Cells, Prof. T.-S. Yang, NCKU/ME
Other Applications A laptop computer using a fuel cell power source can operate for up to 20 hours on a single charge of fuel. (Ballard Power Systems) The world’s first prototype polymer electrolyte membrane fuel cell (on the right) used to provide all residential power needs for a home in Latham, New York. This 7 kW unit is attached to a power conditioner/storage unit that stores excess electricity. (Plug Power)
5-3 Types of Fuel CellsOverview of Fuel Cells • Fuel Cells generate electricity through an electrochemical process in which the energy stored in a fuel is converted directly into DC electricity. • Electrical energy is generated without combusting fuel, so fuel cells are extremely attractive from an environmental stand point.
5-3 Types of Fuel CellsOverview of Fuel Cells • Attractive fuel cell characteristic • High energy conversion efficiency • Modular design • Very low chemical and acoustical pollution • Fuel flexible • Cogeneration capability • Rapid load response
5-3 Types of Fuel CellsOverview of Fuel Cells • Basic operating principle of fuel cells • An input fuel is catalytically reacted in fuel cell to create an electric current. • The input fuel passed over the anode where it catalytically splits into ions and electrons. • The electrons go through an external circuit to serve an electric load while the ions move through the electrolyte toward the oppositely charge electrode. • At electrode, ions combine to create by-products, primarily water and CO2.
5-3 Types of Fuel CellsOverview of Fuel Cells • The figure of basic operating principle
5-3 Types of Fuel CellsOverview of Fuel Cells • Fuel Cell Characteristics
5-3 Types of Fuel CellsOverview of Fuel Cells • Four primary types of fuel cells which are based on electrolyte employed • Phosphoric Acid Fuel Cell • Molten Carbonate Fuel Cell • Solid Oxide Fuel Cell • Proton Exchange Membrane Fuel Cell
5-3 Types of Fuel CellsOverview of Fuel Cells • A comparison of the fuel cell types
5-3 Types of Fuel CellsOverview of Fuel Cells • Fuel cells are typical grouped three section
5-3 Types of Fuel CellsPhosphoric Acid Fuel Cells • The most mature fuel cell technology • Among low temperature fuel cell, it was showed relative tolerance for reformed hydrocarbon fuels. • It could have widespread applicability in the near term.
5-3 Types of Fuel CellsPAFC Design an Operation • The sketch of PAFC operation
5-3 Types of Fuel CellsPAFC Design an Operation • The components of PAFC • Electrolyte : liquid of acid • Electrolyte carriers : Teflon bonded silicone carbide matrix (pore structure→capillary action to keep liquid electrolyte in place) • Anode : platinum catalyzed, porous carbon • Cathode : platinum catalyzed, porous carbon • Bipolar plate : complex carbon plate
5-3 Types of Fuel CellsPAFC Design an Operation • The most designs of PAFC • The plates are “bi-polar” in that they have grooves on both side – one side supplies fuel to anode of one cell, and the other side supplies air or oxygen to the cathode of the adjacent cell.