Process for separating an intake flow consisting essentially of hydrogen, methane and C3/C4 hydrocarbons

摘要

PCT No. PCT/EP93/01182 Sec. 371 Date Apr. 14, 1995 Sec. 102(e) Date Apr. 14, 1995 PCT Filed May 12, 1993 PCT Pub. No. WO94/08923 PCT Pub. Date Apr. 28, 1994Process for separating a feedstock stream essentially consisting of hydrogen, methane and C3/C4-hydrocarbons, which first passes through a pretreatment, such as, e.g., dehydrogenation, after which the feedstock stream undergoes an at least one-stage partial condensation and separation into a C3/C4-hydrocarbon-rich fraction and into an H2/CH4 fraction, after which a partial stream of the H2/CH4 fraction is mixed in the not yet pretreated feedstock stream. The H2/CH4 gas fraction drawn off from first separator (S1) is divided into two partial streams (10, 17), and first partial stream (10) together with liquid fraction (11) of first separator (S1) is fed to a second separator (S2) after partial condensation (W2), C3/C4-hydrocarbon-rich liquid fraction (16), drawn off at the bottom of second separator (S2), together with the second partial stream of H2/CH4 gas fraction (17) from first separator (S1) is conveyed to a stripping column (S3), an H2-rich gas fraction with high purity (13) is drawn off at the top of second separator (S2), and after evaporating in heat exchange (W2) with the process streams to be cooled is mixed with feedstock stream (2, 2a, 2b) before its pretreatment, and a C3/C4-rich product fraction (20) is drawn off at the bottom of stripping column (S3) and an H2-rich gas fraction with less high purity (18) is drawn off at the top of stripping column (S3).