Patent ID: 9103585
Filing Date: 2015-08-11
Classification: C10G,F25J

Abstract:
1. A method of recovering natural gas liquids from natural gas, the method comprising: feeding a vapor portion of a cooled feed gas in a first column to thereby form a first column bottom product and a first column overhead product, and configuring the first column to allow feeding of alternate first and second reflux streams to the first column such that the first column receives the first reflux stream during ethane recovery, and such that the first column receives the second reflux stream during propane recovery; feeding the first column bottom product and a liquid portion of the cooled feed gas to a second column to thereby produce a second column overhead and a second column bottom product; wherein the first column bottom product is used as a reflux for the second column during ethane recovery and as a refrigerant for an overhead condenser of the second column and second column feed during propane recovery; compressing the first column overhead product and (a) expanding a portion of the compressed first column overhead product in a first expansion device to thereby form the first reflux stream during ethane recovery, and (b) expanding the portion of the compressed first column overhead product in a second expansion device to thereby provide cooling to the feed gas by combing with the first column overhead product when a portion of the second column overhead is used as the second reflux stream during propane recovery.