Solvent and method for removal of an acid gas from a fluid stream

• US 9,468,883 B2
• Filed: 03/29/2013
• Issued: 10/18/2016
• Est. Priority Date: 03/29/2013
• Status: Active Grant

• Current Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Original Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Inventors: Remias, Joseph E., Lippert, Cameron A., Liu, Kunlei
• Primary Examiner(s): Smith, Jennifer A
• Assistant Examiner(s): NASSIRI MOTLAGH, ANITA
• Application Number:
  US13/853,186
• Publication Number:
  US 20140294704A1
• Time in Patent Office: 1,299 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B01D 2252/20421 Primary amines
• CPC Class Codes: B01D 2252/20426 Secondary amines
• CPC Class Codes: B01D 2252/20431 Tertiary amines
• CPC Class Codes: B01D 2252/20484 with one hydroxyl group
• CPC Class Codes: B01D 2252/20489 with two or more hydroxyl groups
• CPC Class Codes: B01D 2252/502 having two or more functionalities in the same molecule other than alkanolamine
• 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

A solvent for removal of an acid gas from a fluid stream includes a promoter amine with a pKa of between 6.5 and 10.5 and a tertiary amine with a pKa of between 8.5 and 10.5.

Claims

1. A solvent for removal of an acid gas from a fluid stream, comprising:

a promoter amine comprising a mixture of N-sulfonylamine (SA) and 3-aminopropionitrile (APN), wherein SA comprises 3-5 mol % and APN comprises 1-20 mol %; and

a tertiary amine with a pKa of between 8.5 and 10.5.

2. The solvent of claim 1 including 0.01 to 15.0 weight percent promoter amine, 10.0 to 65.0 weight percent tertiary amine and 34.99 to 89.99 weight percent water.

3. The solvent of claim 1, wherein said tertiary amine is selected from a group of tertiary amines consisting of methyldiethanolamine (MDEA), triethanolamine (TEA), N,N,-dialkylethanolamine, N,N,N′

,N′

-tetraalky-1,8-naphthalenediamine, N,N,-dialkylbenzylamine, 1,4-dialkylpiperazine, N,N,N′

,N′

-tetraalkyl-1,6-hexanediamine, N,N,N′

,N′

-tetraalkyl-1,5-pentanediamine, N,N,N′

,N′

-tetraalkyl-1,4-butanediamine, N,N,N′

,N′

-tetraalkyl-1,3-propanediamine, N,N,N′

,N′

-tetraalkyl-1,2-ethanediamine, N,N,N′

N′

-tetrakis(2-hydroxyethypethyl) ethylenediamine, N,N, N′

,N″

-pentaalkyldiethylenetriamine, N,N,N′

,N′

,N″

-pentaalkyldipropylaminetriamine, N,N,-dialkylcyclohexylamine, N,N,N′

,N′

-tetraalkylbis (aminoethyl)ether, N,N,-dimethyl-2(2-aminoethoxy)ethanol, where alkyl represents any methyl, ethyl, propyl, butyl isomer, and mixtures thereof.

4. The solvent of claim 1, wherein said tertiary amine is selected from a grou of tertiary amines consisting of methyldiethanolamine (MDEA), triethanolamine (TEA), dimethylethanolamine (DMEA), N,N,-dimethylbenzylamine, diethylmonoethanolamine, dipropylmonoethanolamine, 1,4-dimethylpiperazine, N,N,N′

,N′

-tetramethyl-1,6-hexanediamine, N,N,N′

,N′

-tetrakis(2-hydroxyethyl)ethylenediamine, N,N,N′

,N′

,N″

-pentamethyldiethylenetriamine, N,N,N′

,N′

-tetramethylethylenediamine, N,N,N′

,N′

tetramethylpropane-1,3-diamine, N,N,N′

,N′

-tetramethylbutane-1,4-diamine, N,N,N′

,N′

-tetramethyl-1,5-pentanediamine, and mixtures thereof.

5. The solvent of claim 1, wherein said tertiary amine is methyldiethanolamine (MDEA).

6. The solvent of claim 5, wherein said solvent comprises about 0.1 weight percent N-sulfonylamine (SA), about 0.25 weight percent aminopropionitrile (APN) and between about 2.0 and about 65.0 weight percent methyldiethanolamine and a remainder is water.

7. The solvent of claim 1, wherein said acid gas is carbon dioxide.

8. A method of removing an acid gas from a fluid stream, comprising:

contacting said fluid stream with a solvent for removal of said acid gas from said fluid stream, and said solvent including;

(a) a promoter amine comprising a mixture of N-sulfonylamine and 3-aminopropionitrile, wherein N-sulfonylamine comprises 3-5 mol % and 3-aminopropionitrile comprises 1-20 mol %; and

(b) a tertiary amine with a pKa of between 8.5 and 10.5.

9. The method of claim 8, including providing said solvent with 0.01 to 15.0 weight percent promoter amine, 10.0 to 65.0 weight percent tertiary amine and 34.99 to 89.99 weight percent water.

10. The method of claim 8, including using a tertiary amine selected from a group of tertiary amines consisting of methyldiethanolamine (MDEA), triethanolamine (TEA), dimethylethanolamine (DMEA), N,N,-dimethylbenzylamine, diethylmonoethanolamine, dipropylmonoethanolamine, 1,4-dimethylpiperazine, N,N,N′

,N′

-tetramethyl-1,6-hexanediamine, N,N,N′

,N′

-tetrakis(2-hydroxyethyl)ethylenediamine, N,N,N′

,N′

,N″

-pentamethyldiethylenetriamine, N,N,N′

,N′

-tetramethylethylenediamine, N,N,N′

,N′

tetramethylpropane-1,3-diamine, N,N,N′

,N′

-tetramethylbutane-1,4-diamine, N,N,N′

,N′

-tetramethyl-1,5-pentanediamine, and mixtures thereof.

11. The method of claim 8, including methyldiethanolamine (MDEA) as said tertiary amine.

12. The method of claim 8, further including binding acid gas in said fluid stream to said solvent to form an acid gas-solvent complex.

13. The method of claim 12, including separating said acid gas solvent complex from said fluid stream.

14. The method of claim 13, including regenerating said solvent by releasing said acid gas.

15. The method of claim 14, including recycling said regenerated solvent for contacting said fluid stream.