3597.     WARDEN, C. P.  Production of Oils From Coal.  Jour. Chem. Met. Min. Soc. South Africa, vol. 38, 1937, pp. 1-21; vol. 38, 1938, p. 342-347; Chem. Abs., vol. 31, 1937, p. 8886; vol. 32, 1938, p. 4752.

        Conversion of coal into oils requires 2 operations:  (a) Reduction in molecule size from more than 2,000 to 100-400, and (b) the H₂:C ratio must be increased -- for coal from 0.65 to 1.90 and for tar from low-temperature carbonization from 1.25 to 1.90.  To do this, 3 types of operations may be used:  (1) Carbonization, (2) hydrogenation, or (3) catalytic synthesis.  Each is discussed.  Flow sheets for 4 types of plants to produce oil from South African coal are presented and discussed.