Process and device for membrane separation of a mixture containing hydrogen and carbon dioxide as main components

Patent metadata

Field	Value
Publication number	US-12492124-B2
Application number	US-202217873766-A
Country	US
Kind code	B2
Filing date	Jul 26, 2022
Priority date	Jul 26, 2021
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

A process for membrane separation of a mixture containing as main, or even major, components hydrogen and carbon dioxide and also at least one other component, for example chosen from the following group: carbon monoxide, methane and nitrogen, including: heating of the mixture in the heat exchanger, permeation of the reheated mixture in a first membrane separation unit making it possible to obtain a first permeate which is a hydrogen and carbon dioxide enriched relative to the mixture, and a first residue which is hydrogen and carbon dioxide lean, permeation of the first residue in a second membrane separation unit making it possible to obtain a second residue, at least one portion of the first permeate is compressed in a booster compressor and the second residue is expanded in a turbine, the booster compressor being driven by the turbine.

First claim

What is claimed is:

1 . A process for membrane separation of a mixture containing hydrogen and carbon dioxide and also at least one other component chosen from the following group: carbon monoxide, methane and nitrogen, said process comprising:
i) heating of the mixture in a heat exchanger up to a first temperature; ii) separating the mixture reheated to the first temperature, in a first membrane separation unit thereby obtaining a first permeate which is hydrogen and carbon dioxide enriched relative to the mixture and a first residue which is hydrogen and carbon dioxide lean relative to the mixture; iii) cooling of at least one portion of the first permeate in the heat exchanger; thereby producing a cooled first permeate stream, iv) separating the first residue in a second membrane separation unit thereby obtaining a second permeate and a second residue which is hydrogen and carbon dioxide lean relative to the second permeate, and v) compressing the cooled first permeate stream in a booster compressor, expanding the second residue in a turbine and the booster compressor is driven by the turbine.

2 . The process as claimed in claim 1 , wherein at least one portion of the first permeate compressed in the booster compressor is sent to a pressure swing adsorption separation unit in order to extract the hydrogen therefrom.

3 . The process as claimed in claim 2 , wherein the at least one portion of the first permeate compressed in the booster compressor is cooled in the heat exchanger before being sent to the adsorption separation unit.

4 . The process as claimed in claim 1 , wherein the heat exchanger has a first end and a second end, the second end being colder than the first and wherein the at least one portion of the first permeate is cooled up to the second end before being sent to the booster compressor.

5 . The process as claimed in claim 1 , wherein the inlet temperature of the turbine is substantially equal to the temperature at which the second residue leaves the second membrane separation unit.

6 . The process as claimed in claim 1 , wherein the reheated mixture enters the first membrane separation unit at a temperature substantially equal to the temperature at which it leaves the heat exchanger.

7 . The process as claimed in claim 1 , wherein a variable portion of the mixture is not reheated in the heat exchanger and mixes with the reheated mixture upstream of the first membrane separation unit.

8 . The process as claimed in claim 7 , wherein at least one variable portion of the first permeate from the first membrane separation unit is sent directly to the booster compressor without passing through the heat exchanger.

9 . The process as claimed in claim 6 , wherein only one portion of the first permeate compressed in the booster compressor is sent to the heat exchanger.

10 . The process as claimed in claim 1 , comprising a separation step operating at a temperature below 0° C. by distillation and/or by partial condensation in order to separate a gas compressed in a compressor and to produce the mixture to be separated.

11 . The process as claimed in claim 10 , wherein at least one portion of the second permeate is sent to the gas compressor.

12 . The process as claimed in claim 10 , wherein the gas compressed in the compressor is a residual gas from a pressure swing adsorption hydrogen separation unit.

Assignees

• Air Liquide

Inventors

• Leclerc Mathieu
• Pere Felix

Classifications

• C01B2203/0475

  the impurity being carbon dioxide · CPC title

• C01B2203/046

  Purification by cryogenic separation · CPC title

• C01B2203/043

  Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration · CPC title

• C01B2203/0405

  Purification by membrane separation · CPC title

• C01B3/34

  by reaction of hydrocarbons with gasifying agents · CPC title