METHOD AND EQUIPMENT FOR GAS SEPARATION

摘要

A process for the recovery of propane and heavier hydrocarbon components from a hydrocarbon gas stream is disclosed. The stream is divided into first and second streams. The first stream is cooled to condense substantially all of it and is thereafter expanded to the pressure of the distillation column. After expansion, the cooled first stream is directed in heat exchange relation with a warmer distillation stream rising from fractionation stages of the distillation column. The warmed first stream is then supplied to the column at a first mid-column feed position. The second stream is expanded to the column pressure and is then supplied to the column at a second mid-column feed position. The distillation stream is cooled by the first stream sufficiently to partially condense it. The partially condensed distillation stream is then separated to provide volatile residue gas and a reflux stream. The reflux stream is supplied to the column at a top column feed position. The temperatures of the feeds to the column are effective to maintain the column overhead temperature at a temperature whereby the major portion of the C3+ components is recovered. Alternatively, control means may be adapted so that the major portion of the C2+ components is recovered.