초록

Carbon dioxide is removed from CO2 and hydrocarbon containing gaseous streams. In the instance where the hydrocarbons and CO2 are such that hydrocarbons would condense out during CO2 removal, the gas stream is treated in one or more stages to accomplish hydrocarbon composition control.

대표청구항 ▼

Process for treating a gaseous stream comprising: (a) separating a first portion of predominantly higher (C3 and heavier) hydrocarbons from a gaseous stream such that hydrocarbon condensation does not occur from the resulting stream comprising CO2 and at least C1 and C2 hydrocarbons during CO2 remov

Process for treating a gaseous stream comprising: (a) separating a first portion of predominantly higher (C3 and heavier) hydrocarbons from a gaseous stream such that hydrocarbon condensation does not occur from the resulting stream comprising CO2 and at least C1 and C2 hydrocarbons during CO2 removal during Step (b) hereinafter set forth, the gaseous stream comprising CO2 and hydrocarbons including at least C1 and C2 hydrocarbons, and further including C3 and heavier hydrocarbons such that hydrocarbon condensation occurs during removal of CO2 unless the gaseous stream is treated prior to CO2 removal to remove said first portion of the hydrocarbons; then (b) introducing said resulting stream comprising CO2 and at least C1 and C2 hydrocarbons into a permeation zone and separating a first portion of CO2 from said resulting stream in the permeation zone by selective permeation of CO2 across a differentially permeable membrane to produce a CO2 permeate stream and a hydrocarbon enriched first stream comprising C1 and C2 hydrocarbons; and (c) further separating CO2 from the hydrocarbon enriched first stream in at least one CO2 removal zone by cryogenically fractionating the hydrocarbon enriched first stream to produce at least a C1 stream and a CO2 stream.