Natural gas liquefaction.

摘要

A process for liquefying natural gas (50) in conjunction with producing a liquid stream containing predominantly hydrocarbons heavier than methane (41) is disclosed. In the process, the natural gas stream to be liquefied (31) is partially cooled, expanded to an intermediate pressure (14,15), and supplied to a distillation column (19). The bottom product (41) from this distillation column preferentially contains the majority of any hydrocarbons heavier than methane that would otherwise reduce the purity of the liquefied natural gas (50). The residual gas stream (37) from the distillation column (19) is compressed (16) to a higher intermediate pressure, cooled under pressure (60) to condense it, and then expanded (61) to low pressure to form the liquefied natural gas stream.