Recovery method of ammonia from gaseous mixture

• US 6,585,807 B2
• Filed: 04/30/2001
• Issued: 07/01/2003
• Est. Priority Date: 04/28/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Inventors: Ito, Hirofumi, Chikamatsu, Nobuyasu, Mizukami, Masamichi, Umino, Hiroshi
• Primary Examiner(s): SMITH, DUANE
• Application Number:
  US09/844,678
• Publication Number:
  US 20020002905A1
• Time in Patent Office: 792 Days
• Field of Search: 951/78, 951/79, 951/80, 951/93, 951/94, 952/32
• US Class Current: 95/178
• CPC Class Codes: C01C 1/12 Separation of ammonia from gases and vapours as part of the ammonia synthesis process C01C1/04
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

An object of the present invention is to carry out separation recovery of ammonia efficiently from a gaseous mixture containing ammonia and carbon dioxide, without generating a solid ammonium carbamate. A recovery method of ammonia from a gaseous mixture, includes a process (I) in which a gaseous mixture containing ammonia and carbon dioxide is contacted with an organic solvent to allow the organic solvent to absorb ammonia in the gaseous mixture, and a process (II) in which the organic solvent which absorbed ammonia is distilled to separate ammonia from the organic solvent.

Claims

1. A recovery method of ammonia from a gaseous mixture, comprising a process (I) in which a gaseous mixture comprising ammonia and carbon dioxide is contacted with an organic solvent selected from the group consisting of alcohol, ether, ketone, ester, and halogenated hydrocarbon to allow said organic solvent to absorb ammonia, and a process (II) in which said organic solvent which absorbed ammonia is distilled to separate ammonia from said organic solvent.

2. The recovery method of ammonia from a gaseous mixture according to claim 1, wherein said organic solvent separated from ammonia in the process (II) is reused in the contacting step in the process (I).

3. The recovery method of ammonia from a gaseous mixture according to claims 1 or 2, wherein said gaseous mixture is contacted to organic solvent at a temperature of 50°

C. or more in the process (I).

4. The recovery method of ammonia from a gaseous mixture according to claim 1 or 2, wherein said organic solvent is alcohol.

5. The recovery method of ammonia from a gaseous mixture according to claim 4, wherein said alcohol is aliphatic alcohol having a carbon number of 3 to 6.

6. The recovery method of ammonia from a gaseous mixture according to claim 1 or 2, wherein said gaseous mixture further comprises alcohol.

7. The recovery method of ammonia from a gaseous mixture according to claim 6, wherein said gaseous mixture is an exhaust gas from the reaction of urea and alcohol.

8. The recovery method of ammonia from a gaseous mixture according to claim 6, wherein said organic solvent is an alcohol, which is contained in said gaseous mixture.

9. The recovery method of ammonia from a gaseous mixture according to claim 7, wherein said organic solvent is an alcohol, which is contained in said gaseous mixture.