Method to Produce LNG at Gas Pressure Letdown Stations in Natural Gas Transmission Pipeline Systems

摘要

There is described a method to produce LNG at gas pressure letdown stations. A high pressure gas stream is pre-cooled, dewatered, and then divided into two streams: a diverted LNG production stream (LNG stream) and a gas to end users stream (User stream). Carbon dioxide is removed from the LNG stream and the LNG stream is compressed. The LNG stream is then precooled by passing through one or more heat exchangers. Hydrocarbon condensate is removed from the LNG steam by passing the LNG stream through a first Knock Out drum. The LNG stream is then depressured by passing through a JT valve to depressurize the gas vapour exiting the first Knock Out drum and discharge it into a second Knock Out drum where the LNG is captured.