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Welcome to the Biogeochemials Homepage.
Unlike
other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation
fuel needs. The two most common types of biofuels are ethanol and biodiesel. Ethanol is an alcohol, the same
as in beer and wine (although ethanol used as a fuel is modified to make it undrinkable). It is made by fermenting any biomass
high in carbohydrates through a process similar to beer brewing. Today, ethanol is made from starches and sugars, but scientists
are developing technology to allow it to be made from cellulose and hemicellulose, the fibrous material
that makes up the bulk of most plant matter. Ethanol is mostly used
as blending agent with gasoline to increase octane and cut down carbon monoxide and other smog-causing emissions. Biodiesel
is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive (typically 20%) to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel
engines.
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Many technologies have been developed to take
advantage of geothermal energy—the heat from the earth. This heat can be drawn from several sources: hot water or steam
reservoirs deep in the earth that are accessed by drilling; geothermal reservoirs located near the earth's surface, mostly
located in western states, Alaska, and Hawaii; and the shallow ground near the Earth's surface that maintains a relatively
constant temperature of 50°-60° F. This variety of geothermal resources
allows them to be used on both large and small scales. A
utility can use the hot water and steam from reservoirs to drive generators and produce electricity for its customers. The
heat produced from geothermal is also directly applied to various uses in buildings, roads, agriculture, and industrial plants.
Some use the heat directly from the ground to provide heating and cooling in homes and other buildings. Other geothermal resources exist miles beneath the earth's surface in the hot rock and magma there.
In the future, these resources may also be useful as sources of heat and energy. Scientists are stilling trying to figure
out how to use these resources.
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