Pure drinking water is one of the waste products of a hydrogen fuel cell. The water that is discharged by this fuel cell is so pure that it could be consumed by anyone and would not make them sick. Sounds crazy but pure H2O is exactly what a hydrogen fuel cell gives off as its byproduct. A fuel cell is basically an enclosed reaction chamber that converts chemical energy directly into electrical energy with out moving parts. These fuel cells are virtually pollution free and very energy efficient, so much so that its proponents state that increases of efficiency of two to three times that of traditional combustion engines are possible and often seen. It is predicted that fuel cell energy will eventually replace traditional sources of energy and be used in products ranging from cell phones to stock cars.
Fuel cells were first researched as far back as 1839 by Sir William Grove who is regarded as the "Father of the fuel cell". In 1889 two scientists named Charles Langer and Ludwig Mond first started to design and build a fuel cell from coal gas and air but the invention of the combustion engine left little interest for the research to continue. It was not until 1932 that Francis Bacon developed and built the first successful fuel cell. However, this early fuel cell was not demonstrated until 1959. Now in today's time there are fleets of fuel cell automobiles being tested and evaluated for the eventual replacement of the gasoline powered car.
A hydrogen fuel cell is an electromechanical device that combines hydrogen with oxygen from the air to produce electricity, heat and water. There is not a combustion chamber (like that of gasoline fueled engines) or any moving parts so this system of energy production is reliable, quiet and predominantly pollution free.
The technology works by separating the protons from the fuel (hydrogen gas) through a catalyst. A catalyst is a helper in the chemical reaction like the spark is to a fire. The protons then flow through a membrane to later combine with the oxygen to form water. This step also requires the help of a catalyst. The electrons then go to the cathode from the anode to produce electric power.
A more detailed explanation of this would be that a cathode attracts electrons and the anode attracts the protons. Protons have a positive charge and electrons have a negative charge. There is a platinum coating on the anode panel to help separate the protons (H+ ions). There is electrolyte between the anode and cathode panels that will let through protons but not electrons. The electrons are then forced to flow through an external circuit to form electrical current. This current is then the power of the fuel cell. The accumulating protons (H+ ions) left behind then react with the separated negatively charged oxygen atoms to from water and heat with the help of another catalyst in the form of a platinum coating on the cathode. The entire process will continue as long as there is pure hydrogen and oxygen supplied to the fuel cell. The individual fuel cells can then be stacked together. This is called a fuel cell "stack" and the total number of fuel cells in the stack determines the voltage and the total surface area of the panels determines the current. The total electrical power generated can then be calculated by multiplying the current by the voltage. For example if you had a stack with four fuel cells the total electrical power would be calculated by multiplying 4 (four fuel cells) by the total combined surface area the four panels. So the more surface area and the more cells will equal a greater electrical current and thus more power.
The hydrogen fuel cell is much like recharging the liquid battery of today's automobile but the difference being that a fuel cell uses hydrogen gas to produce the recharging power rather then a generator powered by a gasoline engine.
One hurdle that hydrogen fuel cells have to over come and to be successful in our society is to increase the availability and lower the cost of the pure hydrogen fuel. Other fuel gases can be used but they need what is called a reformer to get the pure hydrogen and oxygen mixture for the fuel cell to operate properly. The economy of hydrogen gas is quite better then is gas. For example; a hydrogen fuel cell car will operate for a massive 5000 miles per fill up. Again the problem now is hydrogen availability and this hydrogen must be pure or the fuel cell will not work properly. Currently there is only about 70 hydrogen fuel filling stations world wide. General Motors has projected that it will cost between 10 and 15 billion dollars to build 11,700 new filling stations. That is not a lot of money compared to the 85 billion cable operators pay for cable system installation for television and internet.
The United States spent billions of dollars in the last decade to further the research and development of hydrogen fuel cells along with other types of fuel cell technology. This is in response to the global warming issues and the dwindling fossil fuel reserves in the world. Hydrogen fuel cells will be coming soon and some scientists and economists say as early as 10 years from now while skeptics say 50 years or more. The world infrastructure hurdles will have to be over come in order for fuel cell technology to take hold in the world market as well as perfecting the fuel cell technology itself.
References
Ashley, S. (2005). On the road to fuel-cell cars. Scientific American. 292: 62-69.
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Engineers, S. o. A. (2005). Society of Automotive Engineers.
Institute, H. F. C. (2005). How fuel cells work.
Leslie, J. (1997). Dawn of the Hydrogen Age. Wired: 1-8.