Cryogenic removing of carbon dioxide in small natural gas liquefaction system

摘要

Almost all natural gas includes CO_2 which may be freezed in the heat exchangers duringnatural gas liquefaction. In this paper a small natural gas liquefaction process withcryogenic removing of CO_2 is simulated, optimized and designed. Two switching heatexchangers are used in the liquefaction system. One is cooled by the low temperaturerefrigerant in order to freeze and remove CO_2 from natural gas, the other is regeneratedby the high temperature refrigerant when the CO_2 sublimates. The effect of the pressureand CO_2 concentration of the feed gas on size heat exchangers and the switchingperiod is studied.