3573. VON FREDERSDORFF, C. Continuous Gasification of Powdered-Coal Suspensions by Air-Oxygen and Air-Oxygen-Steam Mixture. Proc. Am. Gas Assoc., vol. 31, 1949, pp. 705-725; Chem. Abs., vol. 44, 1950, p. 8,623.
Describes operation and results of a laboratory-scale coal-gasification unit. Results define the variables affecting the process and indicate the magnitudes of the effects. It is indicated that (1) a slagging operation can be applied successfully to suspension gasification at atmospheric pressure, (2) low gas-residence time is advantageous in increasing the make-gas calorific value, (3) tangential firing can remove more than 50% of the ash in the form of slag, and (4) the use of a combustion tube in the center of the gasifier does not yield any thermal advantage over operation without a tube. Although a satisfactory gasification was accomplished from the standpoint of gas calorific value, it will be necessary to use steam superheated to at least 2,000° F. to decrease the make-gas CO2 content, C conversion, and shift the point of maximum thermal efficiency to closer correspondence with the point of maximum calorific value. Anticipated benefits of the process for the industry include the production of a low-cost base or carrier gas for blending purposes, a gas of intermediate calorific value by oil carburetion of the hot exhaust of the gasification furnace, and a gas of adjusted H2:CO ratio suitable for synthesis purposes.