Partial liquifaction process for a hydrocarbon-rich fraction such as natural gas

摘要

Partially liquefying a gaseous mixture of hydrocarbon in two refrigeration stages liquefies ≤ 90 wt% of the mixture. Some of the residual gas is used to produce electricity. The first refrigeration stage uses an external refrigerant. In the second stage cooling is produced by expanding and vaporizing some of the cooled fluid. An Independent claim is included for a further process for partially liquefying natural gas as above. At the end of the first stage the gas is cooled to below -40 degrees C. Preferred Features: 20-80 wt.% of the mixture is liquefied. The liquid produced at the end of the first phase is a single or dense phase. The residual gas is injected into a gas well to improve production of the well. The expanded and vaporized fluid from the second stage is still sufficiently pressurized for use in a gas turbine driving a power generator or chilled and sent to the bottom of the first of two fractionating columns.