METHOD OF NATURAL GAS LOW-BOILING COMPONENTS EXTRACTION DURING GAS LIQUEFACTION IN CLOSED LOOP AND INSTALLATION FOR ITS IMPLEMENTATION Russian patent published in 2009 - IPC F25J3/00 

FIELD: heating.

SUBSTANCE: invention relates to cryogenic equipment, namely to the liquefaction methods for natural gas and other multicomponent gases. The method of extracting low-boiling natural gas components implies compression of natural gas in a high-pressure compressor, gas purification and drying, sequential cooling in the first methane counter flow heat exchanger, then in an evaporator of a refrigerating machine and in the second methane heat exchanger. The liquid-vapour mixture obtained is supplied through the first ejector to the first separator where the liquefied phase is separated from its vapours which are directed to the counter flow to cool gas in methane heat exchangers and to mix with initial gas supplied to the compressor intake thus forming a circulation loop. The liquid phase from the first high-pressure separator is throttled to the second separator reducing the liquid phase pressure and simultaneously the produced vapour is withdrawn from the second separator by the ejector. The liquefied methane is delivered to customers. Part of the vapours from the counter flow is withdrawn in the amount of 1-15% depending on the content of low-boiling component in the initial natural gas and supplied to an additional condenser-evaporator where it is condensed to 92-98.0% of methane due to the partial usage of the coldness obtained when throttling the liquid phase from the first separator of the natural gas liquefaction system and the additional separator in which the uncondensed low-boiling gas components are separated from methane with their concentration being thus reduced in the counter circulation flow and are supplied either for further processing to produce marketable product or if little are discharged directly into the atmosphere.

EFFECT: increasing gas liquefaction efficiency.

2 cl, 2 dwg