Membrane preconcentration of carbon dioxide from exhaust gas sources

Patent metadata

Field	Value
Publication number	US-12582940-B2
Application number	US-202418642583-A
Country	US
Kind code	B2
Filing date	Apr 22, 2024
Priority date	Apr 21, 2023
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A process of preconcentrating CO 2 in an exhaust gas stream includes flowing all the exhaust gas stream from an exhaust gas source to a CO 2 preconcentration system. Within the CO 2 preconcentration system, at least a portion of the exhaust gas stream is fed to a membrane separation module comprising a polymeric membrane that has a perm-selectivity for CO 2 over N 2 and O 2 , to produce a CO 2 rich exhaust gas. The exhaust gas stream may initially have as low as 400 ppm CO 2 and may be preconcentrated to over 8 vol. % CO 2 , thereby generating a more optimal feed for further treatment processes.

First claim

What is claimed is:

1 . A process of preconcentrating CO 2 in an exhaust gas stream, comprising:
flowing all the exhaust gas stream from an exhaust gas source to a CO 2 preconcentration system; and within the CO 2 preconcentration system, feeding at least a portion of the exhaust gas stream to a membrane separation module comprising a polymeric membrane that has a perm-selectivity for CO 2 over N 2 and O 2 , to produce a CO 2 rich exhaust gas at a permeate side of the membrane separation module and a CO 2 lean gas at a retentate side of the membrane separation module; driving separation at the membrane separation module using a vacuum pump of the CO 2 preconcentration system on the permeate side, wherein the CO 2 rich exhaust gas from the permeate side is sent directly to the vacuum pump to produce a preconcentrated exhaust gas; and wherein the exhaust gas stream has a CO 2 concentration as low as 400 ppm CO 2 , the CO 2 rich exhaust gas has a CO 2 concentration of up to 20 vol. % CO 2 , and wherein the preconcentrated exhaust gas has a CO 2 concentration corresponding to an exhaust gas CO 2 concentration at which another CO 2 treatment system connected to the CO 2 preconcentration system is optimal or otherwise particularly suited.

2 . The process of claim 1 , wherein feeding at least a portion of the exhaust gas stream to a membrane separation module comprises feeding all the exhaust gas stream to the membrane separation module.

3 . The process of claim 1 , wherein feeding at least a portion of the exhaust gas stream to a membrane separation module comprises feeding a first portion of the exhaust gas stream to the membrane separation module, the first portion corresponding to less than all the exhaust gas stream flowed into the CO 2 preconcentration system.

4 . The process of claim 3 , comprising splitting the exhaust gas stream into the first portion of the exhaust gas stream and a second portion of the exhaust gas stream, and mixing the second portion of the exhaust gas stream with the CO 2 rich exhaust gas downstream of the membrane separation module to produce the preconcentrated exhaust gas.

5 . The process of claim 1 , comprising pressurizing or compressing the exhaust gas stream to produce a pressurized or compressed exhaust gas stream; and cooling the pressurized or compressed exhaust gas stream upstream of the membrane separation module.

6 . The process of claim 1 , wherein the exhaust gas stream is a low CO 2 concentration exhaust gas having between 3 and 4 vol. % CO 2 , and the CO 2 rich exhaust gas has greater than 8 vol. % CO 2 .

7 . The process of claim 1 , wherein the exhaust gas stream has between 8 and 10 vol. % CO 2 , and the CO 2 rich exhaust gas has greater than 16 vol. % CO 2 .

8 . The process of claim 1 , wherein the polymeric membrane has a 10 to 100 CO 2 /N 2 perm-selectivity.

9 . The process of claim 1 , wherein the CO 2 preconcentration system has only one membrane separation stage.

10 . The process of claim 1 , wherein flowing all the exhaust gas stream from the exhaust gas source to the CO 2 preconcentration system comprises flowing all the exhaust gas from a gas turbine system to the CO 2 preconcentration system.

11 . The process of claim 1 , wherein flowing all the exhaust gas stream from the exhaust gas source to the CO 2 preconcentration system comprises flowing all the exhaust gas from a natural gas fire heater boiler or steam boiler to the CO 2 preconcentration system.

12 . The process of claim 1 , wherein the CO 2 rich exhaust gas at the permeate side of the membrane separation module has a CO 2 concentration that is between 1.25 and 20 times higher than the exhaust gas stream received by the CO 2 preconcentration system.

13 . The process of claim 1 , comprising providing the preconcentrated exhaust gas to the other CO 2 treatment system for further concentration of the CO 2 in the preconcentrated exhaust gas.

14 . The process of claim 13 , wherein providing the preconcentrated exhaust gas to the other CO 2 treatment system for further concentration of the CO 2 in the preconcentrated exhaust gas comprises flowing the preconcentrated exhaust gas along a preconcentrated stream flow path fluidly connecting the permeate side of the membrane separation module with the other CO 2 treatment system.

15 . The process of claim 13 , wherein the other CO 2 treatment system is not an exhaust gas recirculation/recycle (EGR) system.

16 . The process of claim 13 , wherein the preconcentrated exhaust gas is not sent, either alone or in combination with other streams, as a recycle stream to a gas turbine engine.

17 . The process of claim 13 , wherein the other CO 2 treatment system comprises an amine-based system, or a CO 2 injection system, or a system that converts CO 2 into another chemical, or a combination thereof.

Assignees

• Chevron Usa Inc

Inventors

• Bhuwania Nitesh
• Chinn Daniel
• Jadhav Raja Ankush
• Huang Zihan

Classifications

• B01D2257/504

  Carbon dioxide · CPC title

• B01D2256/12

  Oxygen · CPC title

• B01D2256/10

  Nitrogen · CPC title

• B01D2258/01

  Engine exhaust gases · CPC title

• B01D71/06

  Organic material · CPC title