Carbon dioxide recovery at high pressure

• US 6,497,852 B2
• Filed: 12/22/2000
• Issued: 12/24/2002
• Est. Priority Date: 12/22/2000
• Status: Expired due to Term

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Chakravarti, Shrikar, Gupta, Amitabh
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): Vanoy, Timothy C.
• Application Number:
  US09/742,451
• Publication Number:
  US 20020081256A1
• Time in Patent Office: 732 Days
• Field of Search: 423/220, 423/226, 423/228, 423/229
• US Class Current: 423/228
• CPC Class Codes: B01D 53/1418 Recovery of products
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

Carbon dioxide is recovered from a feed stream whose pressure is up to 30 psia by preferentially absorbing carbon dioxide from said feed stream into a liquid absorbent fluid, pressurizing and heating the resulting stream to a pressure sufficient to enable the stream to reach the top of the stripper at a pressure of 35 psia or greater, and stripping carbon dioxide from said stream in a stripper operating at a pressure of 35 psia or greater and recovering from said stripper a gaseous carbon dioxide product stream having a pressure of 35 psia or greater.

Claims

1. A process for recovering carbon dioxide, comprising

(A) providing a gaseous feed stream comprising carbon dioxide, wherein the pressure of said feed stream is up to 30 psia;

(B) preferentially absorbing carbon dioxide from said feed stream into a liquid absorbent fluid comprising an organic amine absorbent to form a carbon dioxide enriched liquid absorbent stream;

(C) pressurizing said carbon dioxide enriched liquid absorbent stream to a pressure sufficient to enable the stream to reach the top of the stripper in step (D) at a pressure of 35 psia or greater, and heating the carbon dioxide enriched liquid absorbent stream to obtain a heated carbon dioxide enriched liquid absorbent stream, wherein said pressurizing and heating are carried out in any sequence or simultaneously; and

(D) stripping carbon dioxide from said carbon dioxide enriched liquid absorbent stream in a stripper operating at a pressure of 35 psia or greater and recovering from said stripper a gaseous carbon dioxide product stream having a pressure of 35 psia or greater.

2. A process according to claim 1 further comprising recovering stripped liquid absorbent fluid from the stripper in step (D) and recycling said fluid to step (B).

3. A process according to claim 1 wherein the gaseous feed stream has a carbon dioxide content of less than 30 vol. %.

4. A process according to claim 1 wherein said liquid absorbent fluid comprises monoethanolamine.

5. A process according to claim 4 wherein the carbon dioxide enriched liquid absorbent stream in step (C) is pressurized sufficiently so as to reach the top of

the stripper at a pressure of 40 to 55 psia and the stripper in step (D) operates at a pressure between 40 and 55 psia.

6. A process according to claim 2 wherein the heating of step (C) is conducted by heat exchange from said stripped liquid absorbent fluid to the carbon dioxide-enriched liquid absorbent stream before said carbon dioxide-enriched liquid absorbent stream is fed to step (D).