GB707264A - A process for the separation of the constituents of gaseous mixtures - Google Patents

Abstract

In a process for separating a gaseous mixture containing less readily and more readily adsorbed components in which the gaseous mixture is contacted counter-currently with a solid adsorbent which passes thorugh adsorption, rectification, and desorption zones, heat is supplied to the rectification zone as well as to the adsorption zone. In the apparatus shown, adsorbent charcoal passes down a tower 1 either as a compact bed or in the fluidized state. The feed gas introduced at 4 contains methane, C2, C3 and higher hydrocarbons, and nitrogen and hydrogen. Methane, nitrogen and hydrogen pass out of the top of the tower through pipe 18, C2 hydrocarbons are removed at 8, and C3 and higher hydrocarbons at 9. In the desorption zone, the charcoal is treated with steam and heated by a coil 27, and then passes through gas lift pipe 14 and cooler 20 back to the top of the tower. A heating coil 26 is provided at the bottom of the rectification zone and is fed with steam, a mix <PICT:0707264/III/1> ture of diphenyl and diphenyl oxide, or through line 21 with hot charcoal from the bottom of the desorption zone. Two or more heating coils 26 and 27 may be provided and these may be spaced apart. The hot charcoal may also be used in a heating coil in the upper part of the desorption zone. Alternative methods of heating in the rectification zone are to remove part of the charcoal or the vapour, heat it in a separate vessel and return it to the rectification zone. The process may also be used for the separation of paraffins, naphthenes, olefins, diolefins, and aromatics using silica gel as adsorbent, the treatment of catalytic cracking gases or hydrocarbon synthius gas, the separation of methane from nitrogen, the recovery of acetylene from gases of the Wulff process, and the separation of C2 hydrocarbons, hydrogen sulphide, and light oil fractions from coke-oven gas. Specification 650,095 is referred to.