FIELD: chemistry.
SUBSTANCE: method for separating a hydrogen-containing hydrocarbon mixture (C2minus) which, in addition to hydrogen, essentially contains hydrocarbons with two carbon atoms and methane, by means of a distillation column. Fluid (a, c, e) of hydrocarbon mixture (C2minus) is cooled step by step at the first pressure level, during which first condensates (b, d) are separated from fluid (a, c, e). Fluid (e) from hydrocarbon mixture (C2minus), which then remains gaseous, is fed at the first pressure level in to C2 absorber, to the top of which liquid reflux (r) is added, while second condensate (f) is removed from the C2 absorber cube, and gaseous overhead stream (g), preferably containing methane and hydrogen, is recovered in the upper portion of the C2 absorber. Fluid of above gaseous overhead stream (g) from the upper portion of the C2 absorber is cooled to a third temperature level and is moved at a first pressure level to hydrogen separator (8) in which methane-rich third condensate (i) is separated from gaseous overhead fluid (g) leaving gaseous hydrogen-rich stream (h). Fluid pressure of first condensates (b, d) and second condensate fluid (f) is reduced from the first pressure level to the second pressure level which is lower than the first pressure level, and these media are fed to a distillation column which is operated at a second pressure level. Fluid (e) of third condensate (i) that is separated in the hydrogen separator from gaseous overhead fluid (g) from the upper portion of the C2 absorber is used as reflux (r) added to the upper portion of the C2 absorber and is moved from the hydrogen separator to C2 absorber solely by gravity. Invention also relates to a suitable separation section and a corresponding olefin plant.
EFFECT: invention makes it possible to reduce capital investments and simplify the operation of the installation.
8 cl, 3 dwg
