3149a.     ---------------.  [SEBASTIAN, J. J. S.]  Powdered-Coal Gasification.  Effect of Variables.  Ind. Eng. Chem., vol. 44, 1952, pp. 1,175-1,184.

        Very large quantities of low-cost synthesis gas required for the production of synthetic gasoline and other liquid fuels necessitate the large-scale gasification of powdered coals with O₂ and superheated steam.  Investigation was undertaken to determine how the considerable differences among various types of coals influence their relative value for synthesis gas production.  It seemed also that investigation of the effects of other process variables should determine the conditions under which a given coal can be gasified with maximum process efficiency, lowest O₂ requirement, and lowest cost.  Sufficient evidence has been obtained to conclude that young high-volatile coals of high O₂ content yield better results than high-rank, low-volatile coals of low O₂ content.  Yet, high-ash or high-S coals can be gasified as easily as high-grade coals, nor does it make any difference whether the coal is strongly coking or noncoking.  For a given coal of predetermined particle size, gasified in a given generator, at its maximum capacity, a proper combination of the O₂:coal ratio, steam:coal ratio, and steam temperature will result in the maximum completion of gasification and lowest O₂ requirement per unit volume of synthesis gas made.  The beneficial effect of the addition of lime to the powdered coal under certain conditions (slagging generators) has been established in special experiments made.

        ----------.  See abs. 144.