TREATMENT BY MEMBRANE PERMEATION WITH ADJUSTMENT OF THE TEMPERATURE OF THE FIRST RETENTAT DEPENDING ON THE CH4 CONCENTRATION IN THE THIRD AND / OR FOURTH PERMEAT

摘要

Installation for the treatment by membrane permeation of a feed gas flow comprising at least methane and carbon dioxide, comprising: a compressor making it possible to compress the feed gas flow, a first membrane separation unit capable of receiving the gas flow from the compressor and to provide a first permeate and a first retentate, a second membrane separation unit able to receive the first retentate and to provide a second permeate and a second retentate, a third membrane separation unit suitable for receiving the first permeate and providing a third permeate and a third retentate, a fourth membrane separation unit capable of receiving the third retentate and providing a fourth permeate and a fourth retentate, at least a first means for measuring the concentration of CH4 in the third permeate or the fourth permeate or in a flow combining the third permeate or the fourth permeate, and to the self ns means for adjusting the temperature of the first retentate at the inlet of the second membrane separation unit as a function of the measurement taken by the first measuring means; with each membrane separation unit comprising at least one membrane more permeable to carbon dioxide than to methane.