Hydrogen Sources - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 112

have found a way to electrolyze water and produce hydrogen with less
energy. The higher production rate of hydrogen is obtained with high-
temperature electrolysis. An electric current is sent through water that is
heated to about 1,000°C. As the water molecules break up, ceramics are
used to separate the oxygen from the hydrogen. The hydrogen that is pro-
duced has about half the energy compared to the energy required for the
process.
Most of the hydrogen used in the chemical and petroleum industry
is manufactured from natural gas, which has a hydrocarbon molecule of
four hydrogen atoms bonded to one carbon atom. Gasoline is a hydro-
carbon molecule that is made up of eighteen hydrogen atoms that are at-
tached to a chain of eight carbon atoms. High temperature steam is used
to separate the hydrogen from the carbon. If the cost of the natural gas is
$4 per million British thermal units (MMBtu), the cost of the gaseous hy-
drogen will be about $10.00 per MMBtu. If the hydrogen is liquefied, an
additional $8.00 to $10.00 per MMBtu must be added to the cost of the
gaseous hydrogen, making the cost of liquid hydrogen produced by this
method about $20.00/mmBtu. If hydrogen is manufactured from water
with electrolysis equipment, its cost is roughly equivalent to $5/mmBtu
per 10 mills ($5/mmBtu/cent/kWh) and will follow the increasing cost of
energy.
Hydrogen can also be manufactured from coal-gasification facilities
at a cost that now ranges from $8 to $12 per MMBtu, depending on the
cost of coal and the method used to gasify it. But, making hydrogen from
nonrenewable fossil fuels does not solve the problem of diminishing re-
sources or the environmental problems.
Most of the easy-to-get oil has already been found, and increasingly,
exploration efforts have to drill in areas that are more difficult. Many ar-
eas have been closed to drilling in the United States. At some point, in the
future, it may take more energy to extract the remaining fossil fuels than
the energy they contain.
HYDROGEN GENERATION
Hydrogen production has commercial roots that go back more than
a hundred years. Hydrogen is produced to synthesize ammonia (NH 3 ),
for fertilizer production, by combining hydrogen with nitrogen. Another
major use is hydro-formulation, or high-pressure hydro-treating, of petro-