Mixtures of physical absorption solvents and ionic liquids for gas separation

• US 9,321,005 B2
• Filed: 04/30/2013
• Issued: 04/26/2016
• Est. Priority Date: 04/30/2013
• Status: Expired due to Fees

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Broderick, Erin M., Bhattacharyya, Alakananda
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): Bergfelder, Adam
• Application Number:
  US13/873,823
• Publication Number:
  US 20140318370A1
• Time in Patent Office: 1,092 Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2252/30 Ionic liquids and zwitter-ions
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

The invention comprises an absorbent composition and process for purification of gaseous mixtures. The composition comprises a mixture of a physical absorption solvent and an ionic liquid. It was found that the mixtures provided improved absorption of a gas component, such as carbon dioxide, when compared physical absorption solvents.

Claims

1. A method of purifying a gas mixture comprising contacting said gas mixture with a mixture of a phosphonium or an imidizolium ionic liquid and a physical absorption solvent selected from the group consisting of a mixture of dimethyl ethers of propylene glycol (CH₃O(C₂H₄O)_nCH₃ (where n is between 2 and 9)) and N-methyl-2-pyrrolidone in an absorbent zone wherein said ionic liquid and physical absorption solvent mixture absorbs at least one component from said gas mixture, and the said ionic liquid and physical absorption solvent mixture is regenerated to remove said absorbed component or components.

2. The method of claim 1 wherein said mixture comprises from about 5-95 vol % ionic liquid and from about 5-95 vol % physical absorption solvent.

3. The method of claim 1 wherein said mixture comprises from about 25-75 vol % of said ionic liquid and from about 25-75 vol % of said physical absorption solvent.

4. The method of claim 1 wherein said composition comprises from about 40-60 vol % of said ionic liquid and from about 40-60 vol % of said physical absorption solvent.

5. The method of claim 1 wherein said component comprises carbon dioxide.

6. The method of claim 1 wherein said gas mixture comprises a carbon dioxide containing gas mixture.

7. The method of claim 6 wherein said gas mixture is selected from the group consisting of natural gas, flue gas, syngas, and shale gas.