Hydrocarbon gas processing for rich gas streams

摘要

A process for the recovery of ethane and heavier hydrocarbon components from a hydrocarbon feed gas stream. Feed gas stream is cooled into a first and second cooled streams. First and second cooled streams are sent to a cold absorber and separated into a first gas stream and a first liquid stream. First gas stream is expanded and sent to a fractionation tower. At least a part of the first liquid stream is sent to a pre-demethanizer stripper tower. Stripper tower produces a stripper overhead stream and a stripper bottoms stream. Stripper overhead vapor stream is cooled and sent to the fractionation tower as second reflux stream. Stripper bottoms stream is supplied to the fractionation tower. Temperatures and pressures of the streams and columns are maintained to recover a major portion of ethane and heavier hydrocarbon components as a bottoms product stream, and produce a residue gas stream at the fractionation tower overhead. At least a portion of the residue gas stream is recycled, cooled and sent to the fractionation tower as first reflux stream.