Production of Gasoline Substitutes from Coal 270010
NO danger exists of the imminent exhaustion of the petroleum reserves of the United States, as is shown by a committee report published early in 1926 by the American Petroleum Institute, from which figures are given in the following paper. It is reasonable to assume that a sufficient supply of oil will be available for all purposes beyond the time when the demand therefor will be reduced by more efficient use of petroleum products or by the production of substitutes for them.
The possibility of a future shortage of petroleum fuel suitable for automotive engines, however, and of the production of substitutes to avoid such a contingency, is receiving considerable attention in America and Europe. The author presents a general review of the situation and the status of research in the manufacture of gasoline substitutes from coal, of which enormous quantities remain unmined in this Country. Four known methods of extracting such substitutes from coal are
High-temperature carbonization of coal in by-product coke-ovens or in gas-retorts
Hydrogenation of coal
Synthesis of hydrogen and carbon monoxide gases derived from coal, resulting in the production of alcohols
Each method is described briefly and the physical and economic possibilities of each to augment the supply of motor fuel are discussed. Only the first method is an existing industrial process; the others are in the stages of development. The second and third methods seem to offer important possibilities in the relatively near future, while the synthetic process of producing alcohols from coal-gases is interesting from a theoretical point, as it indicates that hydrocarbons usable in present or slightly modified automotive engines can be produced at moderate cost from inferior coals.
Other products than motor fuels are produced by these processes, such as coke, heavy oils, and gases suitable for illumination and heating. The carbonization methods are dependent economically upon the sale of these in addition to the sale of the gasoline substitutes, but the hydrogenating and synthesizing processes may be self-supporting on the liquid products.
Coke produced by low-temperature carbonization is suitable for household use and may be pulverized and burned in industrial plants as powdered fuel; it is also suitable for use in gas-producers. Some motor vehicles are now operated in Europe on producer gas and it is likely that such a solid fuel will be used as a gasoline substitute in this Country in motor-trucks, motorcoaches and tractors that operate continuously during working hours.
Crude tar produced by low-temperature carbonization must be cracked to give any considerable yield of light hydrocarbon from coal, and the crude oil derived by the hydrogenating process is fractionated and distilled to give motor fuel, Diesel-engine oil, fuel oil, and gas.