METHOD FOR SEPARATING A NATURAL GAS STREAM INTO A METHANE-ENRICHED FRACTION AND A FRACTION ENRICHED IN C₂ AND HIGHER HYDROCARBONS

摘要

Method for purifying a feed gas stream comprising methane and hydrocarbons having at least two carbon atoms, comprising the following steps: step a): cooling the feed gas stream in a heat exchanger; step b): feeding the stream from step a) into a first phase separator pot to produce a liquid stream and a gas stream; step c): separating the gas stream from step b) in a membrane permeation unit, thereby producing at least one permeate gas stream and a partially condensed residual stream; step d): feeding the residual stream from step c) into a second phase separator pot to produce a liquid stream and a gas stream; step e): feeding at least a portion of the gas stream from step d) into a Joule Thomson expansion means; step f): heating at least a portion of the expanded stream from step e) by feeding it into the heat exchanger (2) implemented in step a), counter-current to the feed stream.