LNG PRODUCTION IN CRYOGENIC NATURAL GAS PROCESSING PLANTS

摘要

A process for liquefying natural gas in conjunction with processing natural gas to recover natural gas liquids (NGL) is disclosed. In the process, the natural gas stream to be liquefied is taken from one of the streams in the N GL recovery plant and cooled under pressure to condense it. A distillation stre am is withdrawn from the NGL recovery plant to provide some of the cooling required to condense the natural gas stream. The condensed natural gas strea m is expanded (14) to an intermediate pressure and supplied to a mid-column fe ed point on a distillation column (17). The bottom product (41) from this distillation column (17) preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas, and is routed to the NGL recovery plant so that these heavier hydrocarbons can be recovered in the NGL product.