171. BERG, C. H. O. (Union Oil Co. of California). Adsorption Process and Apparatus for Separating Gaseous Hydrocarbon Mixtures. United States Patent 2,609,887, Sept. 9, 1952. Chem. Abs., vol. 47, 1953, pp. 849-850.

Gaseous hydrocarbon mixtures are separated by passing a moving bed of solid granular absorbent through a vertical column consisting of a succession of individual adsorption and reflux zones; the rich absorbent thus formed is passed successively through a heating zone, a seal gas-removal zones, and a cooling zone immediately before being removed from the bottom of the column for reuse. An example of the column operation is the fractionation, by absorption, of a cracked petroleum hydrocarbon gas, which was fed at 150 p. s. i. into a 12-ft.-diameter column at the rate of 2,141 lb.-moles per hr. by using 330,000 lb. of activated vegetable charcoal per hr. The 4 fractions obtained consisted essentially of a H₂-CH₄ mixture, a pure C₂ fraction of ethane and ethylene, a pure C₃ fraction of propane and propylene, and a C₄-rich fraction containing also C₅ and higher hydrocarbons.