Membrane permeate recycle system for use with pressure swing adsorption apparatus

Patent metadata

Field	Value
Publication number	US-11207636-B2
Application number	US-201916560431-A
Country	US
Kind code	B2
Filing date	Sep 4, 2019
Priority date	Sep 4, 2019
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A system that is used for the treatment of a net gas stream is disclosed. The system includes a compressor to produce a compressed gas stream from a net gas stream. The compressor is connected to a pressure swing adsorption unit where the net gas stream is separated to produce a hydrogen product stream and a tail gas stream. Tail gas stream from the pressure swing adsorption unit is sent to a first membrane unit to produce a first permeate stream and a first non-permeate stream. A portion of the tail gas stream is sent to a second membrane unit to produce a second permeate stream and a second non-permeate stream.

First claim

The invention claimed is:

1. A net gas stream treatment system comprising:
a compressor positioned to receive a net gas stream;
a pressure swing adsorption unit positioned to receive a compressed gas stream from said compressor, said pressure swing adsorption unit containing at least two outlets, one of said outlets configured to contain a hydrogen product stream and a second of said outlets configured to contain a tail gas stream, sending the compressed gas stream to a pressure swing adsorption unit to produce a hydrogen product stream and a tail gas stream;
said second of said outlets communicating with a first membrane unit comprising membranes wherein each of said membranes have a permeate and a non-permeate side wherein; and
a second membrane unit communicating with said pressure swing adsorption unit to receive a portion of the tail gas stream and configured to produce a second permeate stream and a second non-permeate stream,
wherein the first membrane unit and the second membrane unit are selective for hydrogen.

2. The system of claim 1 , further comprising a compressor positioned to receive said tail gas stream and positioned to send a compressed tail gas stream to the first and second membrane units.

3. The system of claim 1 , wherein the first membrane unit and the second membrane unit are configured to send the first non-permeate stream and the second non-permeate stream to an absorber unit and wherein the absorber unit is operated to produce a fuel gas stream and a C3+ stream.

4. The system of claim 1 , further comprising a control system communicating to said pressure swing adsorption unit, to control flow of the tail gas stream to the first membrane unit and the second membrane unit.

5. The system of claim 1 , wherein the second membrane unit is configured to recycle the second permeate stream the pressure swing adsorption unit as purge gas.

6. The system of claim 1 , wherein a control system is provided and configured to control a temperature in said first membrane unit and said second membrane unit.

7. The system of claim 4 , wherein the control system is configured to control permeate pressure of the first membrane unit and the second membrane unit by controlling a ratio of permeate flow to membrane feed flow for the first membrane unit and the second membrane unit.

8. The system of claim 4 , wherein the control system is configured to measure an amount of flow of gas to each bank of membranes within each of the first membrane unit and the second membrane unit.

9. The system of claim 4 , wherein a control system for said system is combined with the control system for the pressure swing adsorption unit.

10. The system of claim 4 , wherein a control system for the membranes units is separate from the control unit for the pressure swing adsorption unit.

11. The system of claim 8 , wherein the control system combines the measure of the amount of flow of gas into a single value to control an amount of gas sent to the second membrane unit.

12. The system of claim 1 , combining the first membrane unit and the second membrane unit and further comprises segregation valves with positioners configured to permit slow opening of valves keeping away pressure shock waves.

13. The system of claim 1 wherein each of said membrane units comprises at least two membrane module banks.

14. The system of claim 13 wherein each of said membrane module banks comprises a set of membrane modules.

15. The system of claim 13 wherein each of said membrane module banks has at least one segregation valve configured to separate or join each membrane module bank to another membrane module bank or to said pressure adsorption unit.

16. The system of claim 1 , wherein at least one bank of membrane units configured to operate is at a lower pressure than at least one bank of membrane units.

17. The system of claim 1 , wherein the first membrane unit and the second membrane unit each comprise at least two banks of membranes.

18. The system of claim 1 , wherein the first membrane unit and the second membrane unit each comprise a different membrane polymer.

19. The system of claim 1 , wherein the pressure swing adsorption unit comprises a protective adsorbent layer at an end of an adsorber bed to remove impurities from the second membrane permeate stream wherein said end is configured at an outlet for a hydrogen product.

Assignees

• Uop Llc

Inventors

• Russell Bradley P
• Pandey Gautam
• Wegerer David A
• Elseviers Wim

Classifications

• B01D2256/16

  Hydrogen · CPC title

• B01D2257/702

  Hydrocarbons · CPC title

• B01D2257/80

  Water · CPC title

• B01D53/047 Primary

  Pressure swing adsorption · CPC title

• B01D53/229 Primary

  Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption) · CPC title