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Hydrogen Energy. By Brett Buscher, Sarah O’Connor, Alli McDonough, Bridget Lawson. What is Hydrogen energy?. Hydrogen is an energy carrier, however that energy must be produced from another substance; Hydrogen can be produced from water, Fossil Fuels, and Biomass
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Hydrogen Energy By Brett Buscher, Sarah O’Connor, Alli McDonough, Bridget Lawson
What is Hydrogen energy? • Hydrogen is an energy carrier, however that energy must be produced from another substance; Hydrogen can be produced from water, Fossil Fuels, and Biomass • Because Hydrogen gas cannot be extracted from the atmosphere, and must be extracted from other substances, you must extract the Hydrogen using either electrolysis (water splitting) or steam reforming.
Steam Reforming • Steam reforming is currently the least expensive method of producing hydrogen and is accountable for 95-96% of the hydrogen produced in the United States. It is used to separate hydrogen atoms from carbon atoms in methane (CH4). Unfortunately, because methane is a fossil fuel, the process of steam results in greenhouse gases which are commonly linked with global warming
Electrolysis • Electrolysis is a process that splits Hydrogen from water, which results in no emission but is very expensive at present, It accounts for only 4-5% of Hydrogen production in the United States today, due mostly to the greater cost.
Hydrogen Fuel Cell Structure • The Hydrogen Fuel cells are made up of four parts- the Anode, the Cathode, the Catalyst, and the Proton Exchange Membrane
The anode is the negative part of the fuel cell. It conducts freed hydrogen molecules and sends them into an external circuit The cathode is the positive part of the fuel cell. It conducts electrons from the external circuit to the catalyst and holds the oxygen until it is forced past the catalyst. Anode Cathode
Electrolyte (Proton Exchange Membrane) • The Electrolyte looks like clear kitchen wrap, but can only conduct positive ions. The fact that it must be hydrated in order to work is a problem that must be solved. Its purpose is to separate Hydrogen ions from their electrons pushing the Hydrogen ions through the membrane and sending the electrons through an external circuit.
Catalyst • The catalyst is a piece of carbon paper or cloth covered with a thin sheet of platinum nano-particles. It facilitates the recombination of Hydrogen and Oxygen (from the anode and cathode respectively) with water molecules as the waste.
Pressurized hydrogen gas enters the fuel cell on the anode side. The gas is forced through the catalyst, separating it into to H+ ions and two electrons. The ions go through the catalyst (because they’re positive) and the electrons are forced through an external circuit (where they generate power). Meanwhile… Oxygen gas is forced through the cathode past the catalyst. It forms two highly negatively charged Oxygen ions, which attract the two H+ ions. Each oxygen atom combines with two H2 ions, as well as electrons that have returned from the external circuit, to form water molecules. The Process of Fuel Cells
Other Fuel Cell Facts • Hydrogen fuel cells are essentially the “battery” of Hydrogen. • They combine more Oxygen and Hydrogen to form water, and in the process energy is created • It dispenses steam • Small fuel cells can power electric cars, while large fuel cells can provide electricity in out-of-the-way places without power lines • The most common form of fuel cells are Polymer Membrane Exchange Fuel Cells (PEMFCs) because they have a high power density and low operating temperature, which means they take minimal time to heat up
CO$TS • One commercially offered price for a fuel cell currently is approximately $3,000 per kilowatt, a price considered too high for common use. Though fuel cells will not truly achieve nationwide market penetration until they drop to about $1,500, engineers are constantly working for a cheaper solution • The initial cost setup is really not set for fuel cells in the current market because it really has not in fact penetrated the market and is therefore being sold for a wide variety of prices, many of which vary from the company’s above to as high as $6,000 per kilowatt. • Long term costs tend to be substantially less than the initial costs, eventually coming out to about $1,500 per kilowatt.
Short Term Pollution • The Hydrogen itself does not have any detrimental effects because Hydrogen lives within our atmosphere and the process only exerts water and heat • Pure hydrogen does not naturally exist in nature, so it must be artificially created through the use of some sort of independent energy, most likely fossil fuels, which renders the entire process of using hydrogen energy to avoid the pollution and environmental damage of the fossil fuels pointless
Long Term Pollution • Steam reforming, one of the most common methods of extracting hydrogen, is used to separate hydrogen atoms from carbon atoms in methane, as mentioned earlier. However, because methane is a fossil fuel, the process of steam reforming results in greenhouse gases which are commonly linked with global warming, a long effect on the environment • Besides the use of fossil fuels, Hydrogen has no long term pollution effects, one of the few energies that can make that claim.
Availability • Hydrogen exists all over the earth. It is most commonly found in water, fossil fuels, and biomass. • Water is the most useful of the three sources, due to its abundance among Earth. • However, the efficient use of fuel cells requires pure Hydrogen which does not exist on earth. Therefore, pure Hydrogen must be extracted from the previously mentioned sources. • Biomass is the least efficient source primarily because of its seasonality, limited supplies, it has a low yield, it will degrade the soil, and it is not in fact suitable for pure hydrogen production.
Safety • Because of its energy content, Hydrogen must be handled with as much care as any fossil fuel, however is not extremely dangerous • Hydrogen fuel cells are indeed advantageous in cars if a car were to be lit on fire, due to the fact that Hydrogen rises to the top of the car before catching on fire while gasoline simply explodes, making a Hydrogen fueled car much safer in a scenario of a dire or extremely dangerous crash.
Other Positive Aspects of Hydrogen Energy • Hydrogen has almost an unlimited source unlike most energies and is far more accessible • Gasoline has about a 20% efficiency while Hydrogen has about a 64% efficiency.
The Few Cons of Hydrogen Energy • Because it is such a light gas, it is difficult to store a lot of Hydrogen in a small area, which contradicts with the desires of the engineers who want to design a 300-mile range car. • Liquid Hydrogen would have to be kept at -420oF which is rather difficult • It depends on other energies and really is rather useless as an energy source except for its increase of efficiency (shh…)
