PROCESS FOR CRYOGENIC SEPARATION OF A NATURAL GAS STREAM

摘要

Process for the cryogenic separation of a natural gas feed stream into a gas containing the most volatile compounds in the feed stream and into a liquid product containing the heaviest compounds in the feed stream, comprising at least the steps following: - Step a): at least partial condensation of a natural gas supply stream in a first heat exchange system; Step b): introduction of the at least partially condensed current from step a) into an absorption column at an introduction level located in the lower part of said absorption column, said absorption column producing, at the head, a gas stream containing the most volatile compounds and in the tank, a liquid product; - Step c): introduction of the liquid product from step b) into a fractionation column to obtain, in the fractionation column tank, a liquid product containing the heaviest compounds in the feed stream and, at the head of fractionation column, a distillate, at least partially condensed in a second heat exchange system; - Step d): introduction, at a level located in the upper part of the absorption column, of the gaseous phase of the condensed distillate from step c) as a feed stream to the absorption column; characterized in that the gas stream produced at the top of the absorption column from step b) is used to condense, in the second heat exchange system, the distillate from the head of the fractionation column .