Very pure carbon mon:oxide recovery from gas mixt. - using high and low pressure columns to remove methane and hydrogen@ e.g. for polymer prodn.

摘要

Recovery of very pure C0 from a gas mixt. (I) contg. at least ca. 90 mole-% C0 is carried out by (a) sepg. the gas mixt. in a pressure column (2) into a liq. C0 sump prod. (II), which is rich in CH4 and contains little H2, a liq. C0 side prod. (III), which is free from CH4 and contains little H2, and a gaseous H2 top prod. (IV); and (b) sepg. (II) and (III) in a low pressure column (3) into gaseous very pure C0 (V), which is discharged at the top, and a liq. CH4 fraction (VI), which is discharged from the sump. USE/ADVANTAGE - C0 with extremely low CH4 and very low H2 contents (less than 10 mole-ppm CH4 and less than 1000 mole-ppm H2) is used in polycarbonate chemistry, in the prodn. of acetic and formic acid and in polyurethane technology. The process provides an economical method of producing the relatively small amts. required for these purposes. It give 99.95 mole-% pure C0.