| 摘要 |
A low-pressure olefins recovery process and plant are described. The feed gas is compressed and distilled at a primary distillation pressure. The overhead stream is chilled at a pressure less than 30 kg/cm2 (430 psia) to partially condense the overheads. The primary distillation tower is refluxed with at least a portion of the condensate. The overhead vapor is further chilled and partially condensed and the condensate is fed to a demethanizer. The remaining vapor is cooled in a cold section and the resultant liquid is phase-separated and expanded to provide refrigeration for the cold section. The expanded vapor from the cold section is recycled to the process gas compressor. The bottoms streams from the primary distillation zone and the demethanizer are fractionated into respective streams consisting essentially of ethylene, ethane, propylene, propane, C4's, and C5+.
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