3172.     ---------------.  [SHERWOOD, P. W.]  Byproduct Hydrocarbon Gases.  Gas, vol. 26, No. 5, 1950, pp. 54, 59-61.

        Quantity and composition of byproduct gases from petroleum processing are given as a source of comparison with byproduct gases from Fischer-Tropsch, coal-hydrogenation gases, and shale-oil gases.  Byproduct gases formed during the Fischer-Tropsch synthesis depend to a great extent on the catalyst employed, as well as on the interrelation of operating temperature and CO:H₂ ratio in the synthesis gas, operating pressure, and converter design.  A striking characteristic is the high olefin content (25-60% for the Co catalyst and 20-80% for the Fe catalyst) and the comparatively small amount of C₂ hydrocarbons.  Wide variations in the amount of permanent byproduct gases may be expected.  An average expectancy would be about 1,000 cu. ft. per bbl. of total oil yield.  In addition there may be 150 cu. ft. per bbl. of liquid petroleum gases and another 150 cu. ft. per bbl. of propylene and butene for chemical processing.  Gases from coal hydrogenation differ markedly from the Fischer-Tropsch gases in the complete absence of olefins. The 2 phases of the hydrogenation process yield unequal amounts of byproduct gases; the larger portion being derived from the primary liquefaction.  The composition of the gas is surprisingly independent of the feedsdtock employed and of operating conditions.  Typical byproduct gas from coal liquefaction is about 90% C-C₃ and from the vapor phase about 90% C₃ and C₄.  Unlike the dilute Fischer-Tropsch tail gases with an average heating value of only 650 B.t.u. per cu. ft., the permanent gases from coal hydrogenation are rich enough (1,065 B.t.u. per cu. ft.) to justify cross-country transmission.  Byproduct gases from oil-shale retorting depend on the type of process used, but are normally of low heat value.  Those gases from the hydrogenation of shale oil are quite similar to those from coal hydrogenation.