Membrane permeation treatment with adjustment of the number of membranes used as a function of the pressure of the feed gas flow
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et I'Exploitation des Procedes Georges Claude
InventorsJean-Marc CHAREYRE, Veronique GRABIE, Golo ZICK
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Abstract
A facility and method for membrane permeation treatment of a feed gas flow containing at least methane and carbon dioxide that includes a compressor, a pressure measurement device, at least one valve, and first, second, third, and fourth membrane separation units for separation of CO2 from CH4 to permeates enriched in CO2 and retentates enriched in CH4, respectively. The at least one valve adjusts the number of membranes combined and connected to the flow of gas entering into at least one of the membrane separation units as a function of the pressure recorded by the pressure measurement device.
Claims15
A facility for the membrane permeation treatment of a feed gas flow containing at least methane and carbon dioxide, comprising:
- a compressor for compressing the feed gas flow;
- a first membrane separation unit able to receive a flow of gas from the compressor and supply a first permeate and a first retentate, the first membrane separation unit comprising a plurality of membranes;
- a second membrane separation unit able to receive the first retentate and supply a second permeate and a second retentate, the second membrane separation unit comprising a plurality of membranes;
- a third membrane separation unit able to receive the first permeate and supply a third permeate and a third retentate, the third membrane separation unit comprising a plurality of membranes;
- a fourth membrane separation unit able to receive the third retentate and supply a fourth permeate and a fourth retentate, the fourth membrane separation unit comprising a plurality of membranes;
- a pressure measurement device able to measure a pressure of a flow of gas flowing into or out of the first membrane separation unit;
- and
- at least one valve able to adjusting a number of the plurality of membranes in at least one of the membrane separation units that receive a flow of gas therein as a function of the measured pressure.
A method for the membrane permeation treatment of a feed gas flow containing at least methane and carbon dioxide, comprising the steps of:
- compressing the feed gas flow with a compressor;
- receiving a flow of gas from the compressor at a first membrane separation unit and supplying therefrom a first permeate and a first retentate, the first membrane separation unit comprising a plurality of membranes;
- receiving the first retentate at a second membrane separation unit and supplying therefrom a second permeate and a second retentate, the second membrane separation unit comprising a plurality of membranes;
- receiving the first permeate at a third membrane separation unit and supplying therefrom a third permeate and a first retentate, the third membrane separation unit comprising a plurality of membranes;
- receiving the third retentate at a fourth membrane separation unit and supplying therefrom a fourth permeate and a fourth retentate, the fourth membrane separation unit comprising a plurality of membranes;
- measuring a pressure of either the flow of gas received from the compressor by the first membrane separation unit or a pressure of the first retentate;
- comparing the measured pressure with a setpoint pressure and determining a difference therebetween;
- and
- adjusting, through use of at least one valve, a number of the plurality of membranes of at least one of the membrane separation units that receive a flow of gas as a function of the determined difference between the measured pressure and the setpoint pressure so as to keep a methane concentration of the second retentate constant.
Dependencies are inferred from the claim text.