Chemical Engineering/September 1998
Pure Energy Corp. (New York, N.Y.) plans to commercialize a new gasoline
substitute blended fuels of 87-93 octane, made from cellulosic wastes.
The P-series fuels can be made at a cost similar to that of gasoline.
However, they cut hydrocarbon and carbon monoxide emissions by 35% and 15%,
says Irshad Ahmed, Vice President. The U.S. Department of Energy
(Washington, D.C.) plans to designate P-fuel as an alternative fuel.
P-fuel, invented by Stephen Paul of Princeton University (N.J.), is a blend
of 45-50% ethanol, 15-20% methyltetrahydrofuran (MTHF) and 30-35%
pentanes-plus (C5-C9 natural gas liquids). In winter, 5% butane may be
added for cold starts. Lignocellulose (e.g. agricultural waste) is
subjected to a dilute acid hydrolysis to obtain furfural from the xylose
(C5) fraction. The furfural is hydrogenated in a two-stage catalytic
process to make MTHF. The solids from the hydrolysis go through a second
hydrolysis to liberate glucose (C6), which is fermented to ethanol.
One key to the low cost is that "we use all the cellulosic material", says
Ahmed. Another is the use of inexpensive pentanes-plus in the fuel blend.
Pure Energy is seeking sites to build two plants. Each will process 2,000
dry tons/day of agricultural residues or wood chips, producing about 55
million gal/yr of P-fuel and 12 million gal of excess MTHF.
Out of waste comes a clean, high octane fuel