METHOD AND APPARATUS OF ETHANE EXTRACTION AND TRAPPING Russian patent published in 1995 - IPC

FIELD: chemical industry. SUBSTANCE: hydrocarbon gas stream is divided for first and second streams. First stream is cooled with following condensation, practically, of the whole stream and expansion up to pressure, that is lower, than pressure of distillation column. After expansion and cooling first stream is going to heat-exchanger, in which it is getting in heat-exchanging engagement with much warmer distillation stream, rising from fractionation sections of distillation column. Then division of heated first stream takes place to form cold vapor and stream of liquid. Liquid is fed in column in first position of feeding along center of column, and cooled vapor is fed in column in second position of feeding along center of column. Second stream is expanded up to pressure of column and then is fed in column in third position of feeding along center of column. Distillation stream is cooled by first stream in sufficient degree to make its partial condensation. Then partially condensed distillation stream is divided to ensure feeding of residual flying gas stream and stream of phlegm. Stream of phlegm is fed in column from above. In the cases, in which second stream is being expanded in corresponding expanding device any formed before instant of expansion condensation is combined fully or partially with first stream. The action takes place before instant of cooling and / or expansion or it is fed partially or fully in column in the form of condensed stream along center of column. EFFECT: method and apparatus are used for trapping and extraction of ethane from stream of hydrocarbon gas. 45 cl, 7 dwg, 4 tbl