HYDROCARBON GAS PROCESSING

摘要

A process and an apparatus are disclosed for removing carbon dioxide from a hydrocarbon gas stream. The gas stream is cooled, expanded to intermediate pressure, and supplied to a fractionation tower at a top column feed position. The tower overhead vapor stream is compressed to higher pressure and cooled to partially condense it, forming a condensed stream. The condensed stream is expanded to intermediate pressure, used to subcool a portion of the tower bottom liquid product, then supplied to the tower at a mid-column feed position. The subcooled portion of the tower bottom liquid product is expanded to lower pressure and used to cool the compressed overhead vapor stream. The quantities and temperatures of the feeds to the fractionation tower are effective to maintain the overhead temperature of the fractionation tower at a temperature whereby the major portion of the carbon dioxide is recovered in the tower bottom liquid product.