2242. ------. [METALLGESELLSCHAFT A. G.]. Gas Producers; Gaseous Mixtures. British Patent 431,030, June 28, 1935. Chem. Abs., vol. 30, 1936, p. 273.

In a process as described in British Patent 364,407 (abs. 2283) for obtaining a combustible gas rich in H₂ and CH₄ and in which solid fuel is gasified under high pressure with O₂, or air admixed with O₂, and steam, air and steam are used and the CO and part of the N₂ are removed from the resulting gas in a separate plant. The air is compressed to 20-30 atm., but pressures up to 200 atm. may be used, the higher the pressure the lower the N₂ content of the gas, and steam is mixed with the air (1 : 6), the mixture being superheated to about 500°. CO₂ and H₂S are removed by washing with H₂O under pressure and by treatment with NaOH and the CO and part of the N₂ are removed by cooling. CH₁ and other gaseous hydrocarbons together with H₂ and N₂ being left. The residual CO and N₂ may be used for superheating the gasifying medium. The CO may be converted into CH₄ or H₂ catalytically before its separation from the mixed gases. The separated CO may be converted into CH₄ and, or, H₂, which is mixed with the gas before or after it is treated in the separating plant.