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-It is true that hydrogen is a very explosive fuel, but so is natural gas and gasoline. For example, movies commonly depict automobiles burning up after crashing, and explosions involving natural gas are reported in the press from time to time. -it is possible to use hydrogen as a fuel, that is, a way to store energy, - The process by which we generate hydrogen (and oxygen) from water is called **electrolysis.** - "electrolysis" literally means to break something apart (in this case water) using electricity - Electrolysis is very simple - all you have to do is arrange for electricity to pass through some water between to electrodes placed in the water, as shown in the diagram above. - But if the electricity is produced by //solar cells//, as we suggest in the diagram above, then there will be no pollutants released by our process. - It is very important to note that electrolysis does not depend intrinsically on the generation of heat (although some may be produced, for example, from the turbulence created by the bubbles of gas in the liquid). - Therefore, electrolysis can be (and is) performed at very high efficiencies close to 100%. -If you use a battery, then chances are that the battery was charged with electricity produced by burning fossil fuels, so that the hydrogen you produce isn't produced cleanly. If you use a solar cell, however, then the hydrogen will be produced cleanly, except for any pollutants that were emitted when the cell was made (we say that the solar cell has no "point-of-use" emissions). -If the electrodes are made of metal, and if there is another metal dissolved into the water, then the metal electrode will become plated with the dissolved metal. This process is called //electroplating//, and is used in industry to produce aluminum and also to plate things with gold or silver. -At the cathode (the negative electrode), there is a negative charge created by the battery. This means that there is an electrical pressure to push electrons into the water at this end. At the anode (the positive electrode), there is a positive charge, so that electrode would like to absorb electrons. - water isn't a very good conductor. Instead, in order for there to be a flow of charge all the way around the circuit, water molecules near the cathode are split up into a positively charged hydrogen ion, which is symbolized as H+ in the diagram above (this is just the hydrogen atom without its electron, i.e. the nucleus of the hydrogen atom, which is just a single proton), and a negatively charged "hydroxide" ion, symbolized OH-: - This hydrogen atom meets another hydrogen atom and forms a hydrogen gas molecule: H + H -> H2, and this molecule bubbles to the surface, and wa-la! We have hydrogen gas! -Suppose that you just happen to have some pure hydrogen gas on hand, stored in a container. The hydrogen gas consists of H2 molecules zipping around in a container (hydrogen atoms like to bond together into H2 molecules). - If there also happens to be oxygen gas around (O2), and there is always plenty oxygen in the air (air consists of about 20% oxygen), then the oxygen can react violently with the hydrogen gas, such that the hydrogen //burns,// or //combusts,// with the oxygen to form water and heat, according to the chemical reaction - Therefore, if you have some hydrogen, you can burn it for fuel to generate heat! -Burning fossil fuels such as coal also usually releases other pollutants, including sulfur dioxide, mercury, and uranium to the atmosphere, because these substances are usually present to varying extent in fossil fuels. But if we can obtain hydrogen without producing greenhouse gases or these other pollutants, then hydrogen is a better fuel to use than fossil fuels. Many people are now hopeful that a "**hydrogen-economy**" will soon replace our fossil fuel economy. -There are two obstacles to a hydrogen-economy.
 * **It takes alot of volume (or energy) to store hydrogen** - usually five times or so the volume, at reasonable pressures, needed to store an equivalent amount of energy with gasoline. One company that has made headway on solving this problem, however, is Dynetek (www.dyneteck.com).
 * **There is no hydrogen infrastructure:** Making the transition to a hydrogen economy might mean having to scrap the fossil fuel infrastructure that we have already developed. One company that has made progress on refueling equipment is Stuart Energy ([|www.stuartenergy.com]).

n/a. (after 2000). **Electrolysis: Obtaining hydrogen from water: The Basis for a Solar-Hydrogen Economy**. Retrieved from []