SCIENCE/TECHNOLOGY
Alternative Fuels to Petroleum Gain Increased Attention Oxygenates are most promising of alternative fuel candidates, and Fischer-Tropsch process gaining new prominence Joseph Haggin, C&EN Chicago
With the idea of alternative fuels development regaining currency, a substantial change in viewpoint about how and why fuels are produced may be taking place. Economics remains a principal consideration. But national security, the inexorable decline in petroleum reserves and rise of other hydrocarbon sources, and the issue of environmental protection have emerged as being of more than academic importance in the search for alternatives to petroleum. Problems of developing appropriate fuels for new kinds of vehicles and new fuels for old kinds also exist. Oxygenates, either neat or as additives to fuels, appear to be the principal alternative fuel candidates beyond the petroleum refinery, d chemistry, on the back burner following the oil price drops of a few years ago, may be restored to some prominence as a means both for new fuels and for organic chemicals. Promoting the idea of alternatives to petroleum, the U.S. Alternative Fuels Act of 1988 responded to the potential threats from more than 95% of U.S. fuel requirements being satisfied from petroleum and from nearly half of U.S. petroleum being imported. More recently, development of alternative fuels—methanol for powering automobiles—was advocated by President Bush. Further underscoring interest in this area is a Department of Energy study on
alternative fuels scheduled to be issued by the end of this year. The panic that followed the Arab oil embargo of 1974 produced little in the way of alternative fuels, but it did highlight some of the problems of producing them. Probably the greatest impediment to launching a new era of alternative fuels is the complete dependence of the transport fuels industry on petroleum as a feedstock. The dominance of petroleum has skewed the economics of production in its favor. Nevertheless, over the past few years, significant developments in catalytic chemistry have suggested that alternative fuels from sources other than petroleum are possible and practical. Some of them are even now competing with petroleumbased fuels in some markets. The results of the forthcoming DOE study are already known, in large part, from preliminary status reports. One authoritative view of the study's conclusions is that of G. Alex Mills, senior scientist in the
Center for Catalytic Science & Technology at the University of Delaware. He suggests the report will likely show that methanol may become a serious contender as motor fuel and that a number of other alcohols and ethers will also enter the picture. These oxygenates can be produced with high-octane properties, can be produced from various hydrocarbon sources other than petroleum, and frequently can offer environmental advantages. The oxygenates, says Mills, are the best alternative fuels so far. Contrary to some opinions, he believes that the problems of changeover from gasoline to oxygenates are foreseeable and soluble, although there would be problems, and any change would cost something and be irritating to many people. Methanol would probably be the alternative fuel most difficult to accommodate. Higher alcohols and ethers would be easier. Alcohol fuels would require higher engine compression ratios, and fuel tanks would need to
Current alternative fuels come from synthesis gas fuels & chemicals
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Gasoline Diesel fuel + Chemicals ¥ Methyl te/f-butyl ether
Ci-Ce alcohols * CH4 «
Turbine fuel Auto fuel additives
Isoparaffins
