Charles Edison Fund Edison Innovation Foundation
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Fuel Cells Experiments, Activities, and Useful Information Presented by: Charles Edison Fund Edison Innovation Foundation Prepared by: Harry T. Roman Educational Consultant, Teacher and Inventor 1 © Charles Edison Fund, 2008 Table of Contents Chairman’s Letter..........................................................................................................3 Introduction to Fuel Cells.............................................................................................4 History of Fuel Cells....................................................................................................5 About Fuel Cells...........................................................................................................6 Areas of Fuel Cell Development.................................................................................9 Where Fuel Cells Could be Used..............................................................................11 Experiment--Electrolysis in Action..........................................................................13 The Catalyst Challenge for Fuel Cells.....................................................................15 Activities and Discussions..........................................................................................16 Learn More About Thomas Edison.............................................................................17 Exhibit A- Fuel Cell History Timeline......................................................................18 About the Author and EIF...........................................................................................20 2 Chairman's Letter Fuel cells have the potential to transform how we generate on-site electricity. The technology dates back to 1839, and its modern usefulness is certain. Fuel cell powered cars are probably one of the most dramatic new applications for them. This short book contains experiments, activities, and charts / tables that can help you better understand the fuel cell message. There also are references to other sources of information for follow-up. We hope you enjoy and benefit from all this data. The booklet is designed for classroom use by teachers, as well as individual student and home school learning and experimentation. If Thomas Edison were alive today, he would be an ardent fuel cell enthusiast, having extolled the virtues of alternate energy back in the early 1910’s. He was the world’s greatest inventor. His name is synonymous with creativity and innovation. Thomas Edison not only recognized opportunity, he created it. As the man responsible for the invention of the motion picture, recorded sound, power generation and the light bulb, and the creation of the first extensive R&D facility, he has arguably created more value than any other single human in history. It has been said that Edison is responsible for anywhere from 3% to 5% of the world’s GNP, over $500 billion for the U.S. alone. Two scientific discoveries in his laboratories later led directly to radio and modern electronics, paving the way for today’s telecommunications boom. So join us in this spirit of Thomas Edison. The experiments have been designed to be easy, economical to perform, and insightful. Have fun and learn! The Charles Edison Fund (“CEF”), incorporated in 1948 by Charles Edison was, and continues to be, an endowed philanthropic institution dedicated to the support of worthwhile endeavors generally within the areas of medical research, science education and historic preservation. It both operates programs and makes grants to support these endeavors. Since its inception CEF has served as an extension of the benefactions and aspirations of its Founder, a man of discerning foresight, rare achievement and background. The undersigned, as Chairman and President of CEF, committed the funding to create and print this booklet. The Edison Innovation Foundation (EIF), a sister organization to CEF, is a not-for-profit organization that supports the Edison legacy and encourages students to embrace careers in science and technology. You can learn more about Thomas Edison and how to support our non-profit efforts through our website at www.charlesedisonfund.org and www.thomasedison.org. John Keegan Chairman & President, Charles Edison Fund Chairman & President, Edison Innovation Foundation 3 Introduction to Fuel Cells In the energy world, the less steps it takes to use or convert one energy form into another, the more elegant the system and also the more efficient. Consider the process steps it takes to convert the energy in gasoline to motive power for a car: • Convert chemical energy of gasoline to thermal energy (combustion) • Convert thermal energy to mechanical power (push pistons) • Convert mechanical energy to mechanical energy (rotational motion to rotational motion in crankshaft, transmission, transaxle/differential. This last step involves multiple transformations and trade-offs between torque and speed [i.e.gears]. It is even more complex for making electricity from coal, oil, or natural gas. All these conversion steps tend to rob the process of efficiency. A car is only about 18-22% efficient, that is 18-22% of the energy in the gasoline makes the wheels turn. All that heat radiating from a car is wasted gasoline energy, as is the sound of its operation (engine running, wheel sounds, exhaust noise…etc.). What makes energy conversion processes like photovoltaics or solar cells so attractive is they are an example of direct energy conversion…..sunlight to electricity. This process makes no pollution, because energy is not wasted at conversion interfaces or process steps. Batteries are like this too, converting chemical energy directly to electricity; and so is the subject of this book……fuel cells…..which also converts chemical energy directly to electricity. Fuel cells have the potential of being able to achieve energy conversion efficiencies in the range of 28-40%. Now that would be an interesting alternative to the internal combustion engines we now use in our cars. Fuel cells and batteries are direct energy conversion cousins. Thomas Edison had a visceral feel for this. He long ago, 100 years to be exact, championed the use of battery powered vehicles for most driving activities. The internal combustion engine to him was polluting, and bound to be limited by the future availability of gasoline fuel. There is even more potential benefit from fuel cells. The low temperature heat that is produced from large fuel cells can also be used to provide space heating to nearby structures. This is called cogeneration, the dual generation of energy for both electricity and heat. Under these conditions, fuel cell efficiencies can reach 80-90%; and remain clean for the environment. Versatile fuel cells offer a promising way to generate electricity and on a vastly decentralized basis. ****************************************************************************************** Notes for Teachers and Home Schooling Parents Challenge your students to identify other potential direct energy conversion processes. One is thermoelectric energy conversion, the conversion of heat to electricity; or perhaps the more arcane magneto-hydrodynamics, possible in large scale power plants. ****************************************************************************************** References http://www.fuelcells.org/ http://www.fuelcelltoday.com/ http://www.eere.energy.gov/hydrogenandfuelcells/ 4 History of Fuel Cells The history of fuel cells begins with Sir William Groves, often referred to as the “Father of Fuel Cells”. This historical perspective is rapidly evolving, especially as world oil supplies are becoming tighter than ever. Many believe fuel cells to be the ideal long-term alternative to gasoline powered internal combustion engines, an automotive economy powered by clean and renewable hydrogen fuel. Starting in 1839, the dates shown in Exhibit A at the end of this booklet are considered to be approximate time periods for fuel cell development milestones. ****************************************************************************************** Notes for Teachers and Home Schooling Parents What did the original Groves fuel cell experiment look like? How did he demonstrate the combination of hydrogen and oxygen to make electricity? How might you do this today? ****************************************************************************************** References http://www.sae.org/technology/fuelcells-history.htm http://www.princeton.edu/~chm333/2002/spring/FuelCells/fuel_cells-history.shtml http://www.fctec.com/fctec_history.asp 5 About Fuel Cells Basic Operation There are a number of different fuel cell technologies that can be used for a variety of large and small applications. A popular technology today for potential application in homes, cars, and small commercial buildings, is the PEM, or Proton-Exchange-Membrane fuel cell. Its name describes what is going on inside the cell…an electrochemical reaction in which a hydrogen atom is split into proton and an electron. The proton travels directly across a membrane and combines with an oxygen atom to form water. Meanwhile, the free electron is routed through an external circuit as electricity. Figure 1 shows the process. FIGURE 1 How a Fuel Cell Works End Plate End Plate C A a n t o h d o e d At the cathode, the electrons and At the anode, a platinum e catalyst cause the hydrogen + positively charged hydrogen ions C + combine with oxygen to form water, to split into positive hyrogen a C ions (protons)