Cryogenic process utilizing high pressure absorber column

摘要

A gas processing plant has a de-ethanizer and a refluxed absorber, wherein the absorber operates at higher pressure than the de-ethanizer, and wherein at least a portion of the absorber bottoms product is expanded to provide cooling for the absorber reflux stream and/or the distillation column feed stream. Especially contemplated gas processing plants include propane and ethane recovery plants, and where the gas processing plant is an ethane recovery plant, it is contemplated that the ethane product comprises no more than 500 ppm carbon dioxide.

主权项

1. A method of processing a feed gas, comprising:
(a) separating the feed gas into a liquid portion and a gaseous portion; (b) expanding the liquid portion and feeding the expanded liquid portion directly into a distillation column; (c) supplying, separately from the liquid portion, the gaseous portion to a refluxed absorber as an absorber feed; (c1) wherein the method does not employ a turboexpander; (d) wherein the absorber receives an absorber reflux, and produces an absorber overhead product and an absorber bottoms product, the absorber having an absorber pressure that is greater than a pressure of the distillation column pressure; (d1) reducing pressure of the absorber bottoms product to generate refrigeration cold, and using the refrigeration cold in an exchanger to provide cooling to the absorber reflux; (e) supplying the absorber bottoms product as a distillation column feed, wherein the absorber bottoms product and the expanded liquid portion are fed to the distillation column at different locations, wherein the distillation column produces a distillation column overhead product and a distillation column bottoms product; (e1) separating the distillation overhead product into a liquid portion and a vapor portion, wherein the distillation column receives the liquid portion of the distillation column overhead product as a reflux stream: (f) compressing the vapor portion of the distillation column overhead product to produce a compressed distillation column overhead product vapor; and (g) at least partially condensing the compressed distillation column overhead product vapor to produce the absorber reflux.