A lot more can be done with coal than just burning it to generate electricity
and steam. Its carbon makeup can be chemically transformed into a variety
of value-added solid products - for example, the electrodes used in the
electrolytic process that produces aluminum.
Now, in an program to expand the uses of coal, the Department of Energy
will provide federal funding to advance a process developed at West Virginia
University (WVU) that extracts the carbon from coal by using a powerful
organic solvent. The product is an ash-free, high-quality carbon material.
DOE will provide $289,000 for the one-year project, with WVU contributing
WVU's process mixes a solvent, such as N-methylpyrrolidone, with either
raw, finely ground coal or a hydrogenated coal product. The mixture is
heated to dissolve a fraction of the feed coal. When the residual solids
are removed and the solvent is evaporated for re-use, the product is similar
to coal tars and pitches produced by conventional coking processes. This
is important, because decreased production of coke in the U.S. has reduced
the supply of tars and pitches. This process will make their production
independent of coke production. The pitch itself is made into electrodes
used to produce aluminum.
The process will also allow tailoring of the pitch product properties
by blending the extract from raw coal with extract from hydrogenated coal.
This permits new freedoms in producing pitch for specific applications,
such as advanced carbon materials in the form of foams and other structural
materials. Tailored tar and pitch materials made with this process will
also allow entry into other carbon products markets now dominated by petroleum-based
The process may stand alone or be included as part of a facility that
uses a coal gasifier, such as future power plant. A slipstream of the
coal would be extracted, valuable products retained, and the residual
material would go to the gasifier.
The National Energy Technology
Laboratory (NETL), which implements and oversees the department's fossil-fuel
programs, will manage the project, which was selected under the second
round of a Fossil Energy-wide solicitation that drew 222 proposals in
15 areas of interest.