2733.     POWELL, A. R.  Future Possibilities in Methods of Gas Manufacture.  Transcript of Federal Power Commission hearings, June 1946, 46 pp.

        A comprehensive review of methods and their economic possibilities.  It is concluded that the future raw materials for the manufacture of gas in the northeastern part of the United States will continue to be chiefly bituminous coal and heavy fuel oil.  High-temperature carbonization will continue to be carried out predominantly in byproduct coke ovens.  This process is characterized by relatively high investment cost per unit of gas made, and by high operating credits from coke, tar, and other products.  Costs will be decreased by the development of new byproducts, the upgrading and discovery of new uses for present product, increasing capacity and thermal efficiency of present equipment, and cheaper plant construction.  The location of high-temperature carbonization plants near the point of gas consumption is more economical than their placement at the coal mine.  Low-temperature carbonization of coal has no future interest largely because of low operating credits and a low yield of gas.  The carburetted water-gas process using chiefly coke and heavy fuel oil will remain the major method of manufacturing gas for many years to come.  The most important potential improvement is an increase in the thermal efficiency owing to the use of O₂ which can now be produced at a reasonable price.  Producer gas, because of its low heating value and despite its high thermal efficiency and low cost of manufacture, has no future.  Complete gasification processes as recently developed in Germany (Bubiag-Didier, Pintsch-Hillebrand, Schmalfeldt-Wintershall, Winkler, Lurgi, and Thyssen-Galocsy) are not suitable for use in this country.  The most promising principle appears to be the complete gasification of powdered coal suspended in a stream of O₂ and steam (an H. Koppers development).  Underground gasification as practiced in Russia has little prospect of success in the United States.  The manufacture of oil gas, of liquefied petroleum gases, or re-formed natural gas has only limited possibilities locally.