3893.  ----- [WELTY, A. B.] (Standard Oil Development Co.). Coal Gasification. United States Patent. 2,538,219, Jan. 16, 1951;appl. filed Sept.. 27, 1946. Serial No. 699,656; 27 claims (Cl. 48-206).

Coal or coke added to the water-gas generator is of large enough size particles that it will not be fluidized under conditions used in the water-gas generator. Nonfluidizable ash is removed continually from the bottom of the water-gas generator. There is thus provided a moving solids bed of coal or coke through which a much finer relatively inert heat-carrying solid is circulated. This circulating solid is the same as that being circulated between the water-gas generator and heater. The inert material is mixed with the carbonaceous fines from the water gas generator as it passes to the heater. The fines of low concentration are burned in the heater with air or O₂ to generate heat by formation of CO₂. Conditions are so controlled as to increase O₂ consumption and decrease CO formation, the final result being that the ratio of CO₂:CO in the combustion fumes is 15-20 volumes volumes to 1. The foreign material thus heated is returned to the generator. A commercial mixture of CO and H₂ is obtained.