Production of moderate purity carbon dioxide streams

• US 20070148070A1
• Filed: 12/23/2005
• Published: 06/28/2007
• Est. Priority Date: 12/23/2005
• Status: Abandoned Application

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Chakravarti, Shrikar, Gupta, Amitabh, Burgers, Kenneth
• Application Number:
  US11/315,065
• Publication Number:
  US 20070148070A1
• Time in Patent Office: Days
• US Class Current: 423/220
• CPC Class Codes: B01D 53/1456 Removing acid components
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

A gaseous product stream having a predetermined carbon dioxide content of 10-95 mol. % is produced from a gaseous feed stream containing 3-20 mol. % carbon dioxide by converting a portion of the feed stream to a purified stream containing 95-99.9 mol. % (dry basis) carbon dioxide and adding the purified stream to the remaining portion of the feed stream. Alternately, a portion of the purified stream is stored and added subsequently in response to fluctuating demand for the product stream.

Claims

1. A method for producing a gaseous product stream containing carbon dioxide, comprising

(A) determining the desired carbon dioxide content of the gaseous product stream, provided that said carbon dioxide content is from 10 mol. % to 95 mol. % of said gaseous product stream;

(B) providing a processor which processes a gaseous input stream comprising 3 mol. % to 25 mol. % carbon dioxide and produces a gaseous purified stream comprising 95-99.9 mol. % (dry basis) carbon dioxide and having a pressure greater than the pressure of the gaseous input stream, by a process which includes absorption of carbon dioxide into an amine solution and desorption of the absorbed carbon dioxide from said amine solution;

(C) providing a gaseous feed stream comprising 3 mol. % to 25 mol. % carbon dioxide;

(D) determining the carbon dioxide content of the gaseous purified stream that is produced by processing in said processor a gaseous input stream having the carbon dioxide content of said gaseous feed stream;

(E) determining the amount of a gaseous additive stream, having the composition of said gaseous feed stream, that must be combined with a given amount of the gaseous purified stream having the carbon dioxide content determined in step (D) in order to form a gaseous product stream having the carbon dioxide content determined in step (A);

(F) determining the amount of said gaseous feed stream that must be fed to said processor as said gaseous input stream and processed in said processor in order to produce said given amount of said gaseous purified stream;

(G) dividing said gaseous feed stream provided in step (C) into a first stream and a second stream wherein the ratio of the flow rate of said first stream to the flow rate of said second stream is equal to the ratio of the amount determined in step (E) to the amount determined in step (F);

(H) feeding said second stream to said processor as the gaseous input stream thereto and processing it therein to produce said purified gaseous stream having a carbon dioxide content of 95-99.9 mol. % (dry basis);

(I) raising the pressure of said first stream to the pressure of said purified gaseous stream; and

(J) combining the purified gaseous stream produced in step (H) with the pressurized stream produced in step (I) thereby forming a gaseous product stream having the carbon dioxide content determined in step (A).

2. A method according to claim 1 wherein said gaseous feed stream comprises flue gas.

3. A method for producing a gaseous product stream containing carbon dioxide and providing said product stream at rates that vary over a given length of time, comprising

(A) determining the desired mass flow rate and the desired carbon dioxide content of the gaseous product stream, provided that said carbon dioxide content is from 10 mol. % to 95 mol. % of said gaseous product stream;

(B) providing a processor which processes a gaseous input stream comprising 3 mol. % to 25 mol. % carbon dioxide and produces a gaseous purified stream comprising 95-99.9 mol. % (dry basis) carbon dioxide and having a pressure greater than the pressure of the gaseous input stream, by a process which includes absorption of carbon dioxide into an amine solution and desorption of the absorbed carbon dioxide from said amine solution;

(C) providing a vessel that is capable of receiving a gaseous purified stream from said processor, of holding carbon dioxide fed in said gaseous purified stream, and of controllably discharging a gaseous discharge stream having the composition of said gaseous purified stream;

(D) providing a gaseous feed stream comprising 3 mol. % to 25 mol. % carbon dioxide;

(E) dividing said gaseous feed stream provided in step (D) into a first stream and a second stream;

(F) feeding said second stream to said processor as the gaseous input stream thereto and processing it therein to produce said purified gaseous stream having a carbon dioxide content of 95-99.9 mol. % (dry basis);

(G) determining the amount of a gaseous stream having the carbon dioxide content of the gaseous purified stream, and the amount of a gaseous additive stream having the composition of said gaseous feed stream, that must be combined in order to form a gaseous product stream having the mass flow rate and the carbon dioxide content determined in step (A);

(H) raising the pressure of an amount of said first stream determined in step (G) to the pressure of said purified gaseous stream;

(I) combining a purified gaseous stream produced in step (F) with the pressurized stream produced in step (H) and optionally with an amount of gaseous discharge stream from said vessel, thereby forming a gaseous product stream having the mass flow rate and the carbon dioxide content determined in step (A); and

(J) intermittently or continuously feeding a gaseous purified stream from said processor into said vessel.

4. A method according to claim 3 wherein said vessel is capable of holding at least a portion of said carbon dioxide as a gas.

5. A method according to claim 3 wherein said vessel is capable of liquefying at least a portion of said carbon dioxide, of holding liquefied carbon dioxide, and of revaporizing said liquefied carbon dioxide.

6. A method according to claim 3 wherein said vessel is capable of solidifying at least a portion of said carbon dioxide, of holding solidified carbon dioxide, and of revaporizing said solidified carbon dioxide.

7. A method according to claim 3 wherein said gaseous feed stream comprises flue gas.

8. A method according to claim 7 wherein said vessel is capable of holding at least a portion of said carbon dioxide as a gas.

9. A method according to claim 7 wherein said vessel is capable of liquefying at least a portion of said carbon dioxide, of holding liquefied carbon dioxide, and of revaporizing said liquefied carbon dioxide.

10. A method according to claim 7 wherein said vessel is capable of solidifying at least a portion of said carbon dioxide, of holding solidified carbon dioxide, and of revaporizing said solidified carbon dioxide.