| 摘要 |
A process for the recovery of ethane, ethylene, propane, propylene and heavier hydrocarbon components from a hydrocarbon gas stream is disclosed. The stream is cooled to partially condense it, then separated to provide a first vapor stream and a first condensed stream. The first vapor stream is divided into first and second streams, then the first stream is combined with the first condensed stream. The combined stream is cooled and expanded to an intermediate pressure to partially condense it, then separated to provide a second vapor stream and a second condensed stream. The second vapor stream is cooled at the intermediate pressure to condense substantially all of it and is thereafter expanded to the fractionation tower pressure and supplied to the fractionation tower at a top feed position. The second condensed stream is subcooled at the intermediate pressure, expanded to the tower pressure, and is supplied to the column at a first mid-column feed position. The second stream is expanded to the tower pressure and is then supplied to the column at a second mid-column feed position. The quantities and temperatures of the feeds to the column are effective to maintain the column overhead temperature at a temperature whereby the major portion of the desired components is recovered. In an alternativeembodiment, the combined stream is cooled at essentially inlet pressure to partially condense it, then separated at pressure to provide the second vapor stream and the second condensed stream.
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