Recovering condensables from natural gas

摘要

To recover condensates from natural gas the raw gas is sent to a high-pressure separator (4) and the incondensable gas is sent to the first stage of an expansion turbine (16) and expanded to a pressure nearly equal to that of the head of a fractionation column (25, 28, 29) composed of three sections, top (25), intermediate (29) and bottom (28). The liquids from the separator (4) are expanded in a second separator (14) and fed to the bottom section (28). The gas from the second separator (14) is mixed with the exhaust from the first turbine stage (16) and fed to the lower portion of the top section (25) to the head of which there is sent the liquid issuing from the intermediate section (29). The latter receives the exhaust from the second turbine stage (36) which is fed by the gas from the top section (25) head. The liquid on the bottom of the top section (25) is fed to the bottom section (28 ). The residual gas is drawn from the top of the intermediate section (29) is compressed by the coaxial compressor to the turbine whereas the condensates are drawn from the bottom section (28).