Liquefaction of natural gas with natural gas recycling

摘要

Natural gas liquefaction method wherein the natural gas is cooled, condensed and subcooled by indirect heat exchange with two cooling mixtures to a temperature such that the natural gas does not remain entirely liquid under pressure after expansion to the atmospheric pressure. The liquid natural gas under pressure is expanded to form a gas phase and a liquid phase. The gas phase can be either compressed and recycled to the process inlet, or used as a fuel. The liquid phase is expanded to form a gas phase and a liquid phase. The gas phase is compressed and recycled to the process inlet. The liquid phase constitutes the liquefied natural gas produced.