Wednesday, June 27, 2007

Hydrogen- For Fuel

HYDROGEN - AN ENERGY CARRIER

An energy carrier is a substance or system that moves energy in a usable form from one place to another. Electricity is the most well-known energy carrier. We use electricity to move the energy in coal, uranium, and other energy sources from power plants to homes and businesses. We also use electricity to move the energy in flowing water from hydropower dams to consumers. It is much easier to use electricity than the energy sources themselves.
Like electricity, hydrogen is an energy carrier and must be produced from another substance. Hydrogen is not widely used today but it has great potential as an energy carrier in the future. Hydrogen can be produced from a variety of resources (water, fossil fuels, biomass) and is a byproduct of other chemical processes. Unlike electricity, large quantities of hydrogen can be easily stored to be used in the future. Hydrogen can also be used in places where it’s hard to use electricity. Hydrogen can store the energy until it’s needed and can be moved to where it’s needed.

HOW IS HYDROGEN MADE?
Since hydrogen doesn't exist on earth as a gas, we must separate it from other elements. We can separate hydrogen atoms from water, biomass, or natural gas molecules. The two most common methods for producing hydrogen are steam reforming and electrolysis (water splitting). Scientists have even discovered that some algae and bacteria give off hydrogen.
Steam reforming is currently the least expensive method of producing hydrogen and accounts for about 95 percent of the hydrogen produced in the United States. It is used in industries to separate hydrogen atoms from carbon atoms in methane(CH4). Because methane is a fossil fuel, the process of steam reforming results in greenhouse gas emissions that are linked with global warming.
Electrolysis is a process that splits hydrogen from water. It results in no emissions but it is currently a very expensive process. New technologies are being developed all the time. Hydrogen can be produced at large central facilities or at small plants for local use. Every region of the country (and the world) has some resource that can be used to make hydrogen. Its flexibility is one of its main advantages.

USES OF HYDROGEN
About 7.8 million metric tonnes (17.6 billion pounds) of hydrogen are produced in the United States today, enough to power 20-30 million cars or 5-8 million homes. Nearly all of this hydrogen is used by industry in refining, treating metals, and processing foods. Most of this hydrogen is produced in just three states: California, Louisiana, and Texas.

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