Hydrocarbon gas processing

摘要

A process and an apparatus for recovering heavier hydrocarbons from a hydrocarbon gas stream is disclosed. The stream is cooled and divided into first and second streams. The first stream is further cooled and divided into first and second portions. The first and second portions are expanded to the fractionation tower pressure and supplied to the tower at upper mid-column feed positions after the expanded second portion is heated. The second stream is expanded to tower pressure and supplied at a mid-column feed position. A distillation vapor stream is withdrawn above the feed point of the second stream, combined with a portion of the tower overhead vapor stream, compressed to higher pressure, and cooled to condense at least a part of it, forming a condensed stream. At least a portion of the condensed stream is expanded to tower pressure and directed to the tower as its top feed.