Fuel Cells Essay, Research Paper
Today many Americans face a lot of economical and environmental challenges. There is pollution in the air, water, and even lying on the ground all around them. Oil and gasoline products derived from petroleum are skyrocketing in price. Brownouts and blackouts are occurring in heavy power usage areas in the United States. What do these problems all have in common; a common solution: Fuel cell technology. A fuel cell is as defined by Webster is an electrochemical generator that produces direct current from a chemical reaction, as from combining oxygen and hydrogen. When hydrogen and oxygen are combined in the fuel cell the results are direct electric current and the production of water as waste. Fuel cells are very efficient in producing electricity without the harmful pollutants. In a fuel cell there are no moving parts so there is no noise. They have excellent reliability and long operation lives. Fuel cells can use multiple fuels such as natural gas, methanol, gasoline, and hydrogen to operate (ballard.com). This sounds almost like a science-fiction fantasy, but in reality they do exist.Many people that have heard of fuel cells believe it is a relatively new discovery in technology. When actually fuel cells have been around since the early 1800’s says Klein. The first true fuel cell was invented by a man the name of William Robert Grove (Klein 99). Grove was a Judge that found recreation in science, especially electrochemistry. He constructed a cell of what he called a “gaseous voltaic battery”, according to Klein. The cell was made of two well-separated electrodes formed from platinum foil, soaked in diluted sulfuric acid (Klein 100). Grove believed that the platinum would act as a catalyst to speed up the reaction, and the sulfuric acid would be the electrolyte or conductor. Grove used pure hydrogen and oxygen gas to accomplish the energy reaction. The reaction was a success producing voltage and releasing water as a byproduct. Klein explains Groves process like this:Ionization took place among sulfuric acid molecules in electrolyte solution, resulting in two positively charged hydrogen ions and one sulfate ion with double negative charge. When molecules of hydrogen gas come into contact with the wet platinum electrode, “chemisorption” occurred. It meant that each formerly paired hydrogen molecule crowded against the platinum electrode as two separate activated atoms of hydrogen. These atoms became hydrogen ions and surrendered their single electrons to the platinum metal, through which the stream of electrons flowed into the external circuit. A like electron flow returned to the cell through the opposite electrode. The resulting negative charge on that electrode attracted to it the wandering hydrogen ions from the electrolyte. Ions reaching the electrode receive the lacking electron, becoming neutral highly active hydrogen atoms. At that same electrode the oxygen atoms separate and join the hydrogen atoms producing water (Klein 102-3). This is how a basic hydrogen-oxygen fuel cell works in layman’s terms: The hydrogen is sent through the electrolyte bath containing metal plates. It reacts with oxygen, which produces electric current and water. Multiple cells can be stacked together to increase the voltage.Fuel cells first gained attention in the early 1960’s. NASA used fuel cells on several of their space missions. According to Klein on august 21, 1965 Gemini V launched from Cape Kennedy with two astronauts and a fuel cell system designed to operate the shuttle in space. The system made by General Electric was intended to deliver power at rates of up to two kilowatts during an eight-day space mission (Klein 10). Klein says the fuel cell system weighted about four and a half times less then a storage battery that would have only supplied power for four days. The first Apollo mission combined more than fifty pounds of compressed hydrogen gas with 425 pounds of compressed oxygen gas. The fuel cell extracted the electric current and released around sixty gallons of drinkable water, eliminating the need for heavy water tanks onboard (Klein 8). This is a huge advantage of fuel cell use in the space program where weight is an important factor. Since the use of fuel cells in the space program, the interest has been limited to academic and U.S. department of energy research says Ferry. This is because of the high cost of platinum. When it was introduced to the space program cost was not an issue, performance was the only thing that mattered. Today’s fuel cells operate the same as the 1960’s space programs but some of the parts have changed. According to Alex Scott there are five basic types of fuel cells, each with advantages and disadvantages for stationary and mobile uses. For all of the families of fuel cells it is the electrolyte that defines the type of cell. The first type of cell is the Phosphoric acid cell. This cell operates at low temperatures. It is typically for use as a backup power generator for critical situations like hospitals. Steam is a byproduct of the cell. Next is the solid oxide cell. The cell uses zirconium oxide for the electrolyte. The cell can generate hydrogen directly from the hydrocarbon fuel so it does not have to go through a separate process to form hydrogen. Next is the Direct Methanol fuel cell or the DMFC. This cell runs on methanol and there is no oxidation of hydrogen. Liquid methanol is the fuel being oxidized. This cell is being considered in the automotive industry. This fuel cell releases a small amount of carbon dioxide as a byproduct. Next to last is the Molten Carbonate. This cell is a high temperature cell that can use most fuels for operation. The temperature of operation is so high it can only be used in industrial applications. The last family of cells is the Polymer Electrolyte Membrane or “PEM”. This fuel cell is the most widely used and studied fuel cell. It is very light and portable. The electrolyte in the cell is a type of plastic, and is usually referred to as a membrane. The appearance of the membrane varies depending on the manufacturer, but the most common one is Nafion made by Dupont says Rhoda. The membrane looks like a piece of really thick plastic wrap. Rhoda believes the thickness to be comparable to somewhere between two to seven pieces of paper varying on the use of the cell. This fuel cell is key to the environment, because it is the fuel cell most automotive manufacturers are interested in.
According to Ferry, when fuel cells were gaining attention from NASA in the 60’s, Detroit had ruled the use of them out till the early 90’s. The reason is because NASA used a lot of precious metal in the fuel cells, and it would cost too much to mass-produce. The cost of precious metal in the fuel cells made for NASA was about $30,000 per cell says Ferry. In 1994 the Los Alamos Research Laboratories developed new cells that use between $200 and $300 worth of platinum per cell stack. This sparked an interest in the big three. According to Dale Jewett of the Detroit News, DaimlerChrystler AG has unveiled a concept car called the NECAR4. This car is based on the Mercedes-Benz A-class. The fuel cell components are installed in the seven-inch sub-floor. The addition of all the fuel cell components and the hydrogen storage tank adds another 1000 pounds to the already 2000 pound car says Jewett. While weighing in at over 3000 pounds the NECAR4 accelerates from 0-30 in about six seconds and has a top speed of 90 miles per hour. The range on a full tank of fuel is approximately 280 miles says Jewett. That is about 65 miles a gallon. The NECAR4 use’s hydrogen as a fuel, the commercial vehicle will likely run on methanol that is converted to hydrogen on the vehicle before entering the cell says Jewett. Using methanol reduces the problem of not having enough hydrogen refueling stations, but means the vehicle will emit carbon dioxide as part of the conversion process. While fuel cell componentry has been greatly reduced in size over the last five years, Daimler-Chrysler’s first fuel cell vehicle was a commercial van with room for only a passenger and a driver. This was because the cargo area was filled with the fuel cells, says Jewett. A mass-produced fuel cell car would now cost about $30,000 for the fuel cell hardware alone. This is why they are not readily available yet. Daimler-Chrystler plans to begin commercial production of a fuel cell powered vehicle in 2004. They plan to spend over 1.4 billion dollars in technology to produce the fuel cell powered vehicles reports Jewett.The NECAR4 by Daimler-Chrysterl is only one of the many automakers working toward a zero emissions vehicle. Ford, General Motors, Toyota, Volkswagen, Nissan, and BMW are also working with fuel cells. A fuel cell manufacturing company called Ballard Power Systems of Vancouver Canada has been producing fuel cells for automotive use since 1989 (ballard.com). Ballard power systems considers the internal combustion engine as a thing of the past, because of the process it takes to create energy. The internal combustion engine operates by burning fuel to create heat, heat is converted into mechanical energy and then motive power, or by turning a generator, electric power. The efficiency is greatly compromised by heat and friction. Ballard considers fuel cells twice as efficient in extracting power from fuel because the cells convert fuel directly to energy from an electrochemical reaction. Ballard Power Systems made a business venture with Dailmer-Chryster and Ford, to produce a working fuel cell city bus. They have produced several buses that have been in operation since 1999. They are being tested in Chicago and in Vancouver. The buses are large enough to conceal the large fuel cells and the hydrogen tanks that power it (ballard.com). They were placed in these cities because of the high air pollution. Automobiles are responsible for fifty percent of the ozone pollution in urban areas and seventy-eight percent of all carbon monoxide emissions in the United States (www.epa.gov). Worldwide, over one billion people living in urban areas are suffering from severe air pollution, and according to the EPA, over 700,000 deaths result each year. There are over 200 million gasoline-powered cars in the United States today and that number is expected to rise to 270 million by 2010 says Evarts. With the increase in cars comes an increase in pollution. Some states have taken the initiative to lower their problem with pollution. California adopted a low emissions vehicle act, says Kuttner, which required the seven largest auto manufacturers to begin reducing tail pipe emissions and to introduce zero emission vehicles by 1998. According to Kuttner this act was changed in 1996 to demand that beginning in 2003, ten percent of all new vehicles will be required to be zero emission or near zero vehicles. Fuel cells were developed for and have been used in the space program to provide electricity and drinking water for astronauts. Today, fuel cells have many practical uses. Fuel cells can be used as power stations for locations that do not have power grid access. They can serve as a backup or standby for incidents like the California brownout. They can be placed in an individuals home to power the entire house. According to Ballard, fuel cells are being created to power laptop computers, cellular telephones, and other portable devices. Development in fuel cell technology is focusing on local, national, and global environmental needs. People need to encourage new technology, instead of fearing it. Paying a little extra for something that in the long run will be an investment in one’s health is a smart thing to do. After all in a world of increasing waste and air pollution environmental limits exist. A change has to occur in the system before the polluters become the polluted.