Environmental Engineering Reference
In-Depth Information
Tropsch process is one of the oldest to be
used on any large scale. It was developed in Germany in
the
The Fischer
-
s to convert coal to a liquid fuel. It begins with
the production of what is called syngas, a mixture of
hydrogen and carbon monoxide, from coal and high-
temperature steam. Further chemical reactions can yield
liquid fuels. The use of liquid fuel produced from coal
emits more greenhouse gases than gasoline. However,
coal is not a necessary input though carbon is, and the
carbon can come from plant material. The coal-based
process is in use today and some are interested in making
an ef
cient version based on plant material.
Pyrolysis is a process that heats carbon-based materials
in the absence of oxygen and can produce in its
rst stage
the same kind of syngas that comes from the Fischer
-
Tropsch process. If plant material supplies the carbon,
it does not enhance greenhouse gas emissions. What
comes after that depends on the rest of the process.
Today, it is mostly the syngas that is used, but, as in the
case of syngas from coal, the process can go on to produce
liquid fuels. For those interested in what is happening
worldwide, enter Pyrolysis in the Google search box and
you will
find many companies working in the area.
Our familiar natural gas, methane, is produced from
waste in land
lls and manure ponds. In some places this
gas is being captured and either fed into pipelines or used
directly for local energy production. This is a winner in
the greenhouse gas
fight because methane is an even
stronger greenhouse gas than CO
. The conversion of
methane into CO
reduces the greenhouse effect in two
ways. First, it reduces the impact of the gas emitted.
Second, it displaces other fossil fuels that would have been
