Gas sweetening solvents containing quaternary ammonium salts

• US 10,449,483 B2
• Filed: 08/27/2014
• Issued: 10/22/2019
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Laroche, Christophe R.
• Primary Examiner(s): Orlando, Amber R
• Assistant Examiner(s): Shao, Phillip Y
• Application Number:
  US14/914,979
• Publication Number:
  US 20160206992A1
• Time in Patent Office: 1,882 Days
• Field of Search: None
• 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 2252/2053 Other nitrogen compounds
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1462 Removing mixtures of hydrogen sulfide and carbon dioxide
• CPC Class Codes: B01D 53/1468 Removing hydrogen sulfide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents

Abstract

A method of treating oil and gas streams comprising H₂S and a carbon oxide, the method including the step of treating the oil and gas stream with an amine solution having an alkanolamine and a quaternary ammonium salt, wherein the amine solution selectively removes the H₂S over the carbon oxide.

Claims

1. A method of treating oil and gas streams comprising H₂S, and a carbon oxide, said method comprising the step of:

treating said gas stream with an amine solution comprising a first tertiary alkanolamine and a methylated quaternary ammonium salt;

wherein said methylated quaternary ammonium salt reacts with a primary or secondary alkanolamine present in said oil and gas streams, producing a second tertiary alkanolamine; and

wherein said second tertiary alkanolamine and said amine solution selectively remove said H₂S over said carbon oxide.

2. The method of claim 1, wherein said amine solution comprises from about 0.1 wt % to about 99 wt % said methylated quaternary ammonium salt.

3. The method of claim 2, wherein said amine solution comprises from about 0.1 wt % to about 5 wt % said methylated quaternary ammonium salt;

and

wherein said amine solution comprises from about 15 wt % to about 99 wt % said first tertiary alkanolamine.

4. The method of claim 3, wherein said first tertiary alkanolamine is selected from the group consisting of methyldiethanolamine (MDEA), triethanolamine (TEA), dimethylethanolamine (DMEA), diethylethanolamine (DEEA), 3-dimethylaminopropane-1,2-diol (DMAPD), 3-diethylaminopropane-1,2-diol (DEAPD), 2-dimethylaminopropane-1,3-diol, 2-diethylaminopropane-1,3-diol, 2-(hydroxyethyl)-2-dimethylaminopropane-1,3-diol (DMTA), 2-(hydroxyethyl)-2-diethylaminopropane-1,3-diol (DETA), tert-butoxyaminoethoxyethanol (TBAEE) and mixtures thereof.

5. The method of claim 1, wherein said methylated quaternary ammonium salt is added to said amine solution during treatment of said oil and gas stream.

6. The method of claim 5, wherein said amine solution comprises from about 0.5 wt % to 99 wt % said quaternary ammonium salt;

and

wherein said amine solution comprises from about 0.01 wt % to about 60 wt % said first tertiary alkanolamine.

7. The method of claim 6, wherein said first tertiary alkanolamine is selected from the group consisting of methyldiethanolamine (MDEA), triethanolamine (TEA), dimethylethanolamine (DMEA), diethylethanolamine (DEEA), 3-dimethylaminopropane-1,2-diol (DMAPD), 3-diethylaminopropane-1,2-diol (DEAPD), 2-dimethylaminopropane-1,3-diol, 2-diethylaminopropane-1,3-diol, 2-(hydroxyethyl)-2-dimethylaminopropane-1,3-diol (DMTA), 2-(hydroxyethyl)-2-diethylaminopropane-1,3-diol (DETA), tert-butoxyaminoethoxyethanol (TBAEE) and mixtures thereof.

8. The method of claim 4 or 7, wherein said amine solution additionally comprises an adjuvant selected from the group consisting of a corrosion inhibitor, an antifoaming agent and a stripping aids or mixtures thereof.

9. The method of claim 1, wherein said methylated quaternary ammonium salt is selected from the group consisting of 2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium bromide;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium chloride;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium iodide;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium bicarbonate;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium carbonate;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium sulfate;

2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethylethanaminium phosphate;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium chloride;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium bromide;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium iodide;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium bicarbonate;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium carbonate;

2,3-dihydroxy-N,N,N-trim thylpropan-1-aminium sulfate;

2,3-dihydroxy-N,N,N-trimethylpropan-1-aminium phosphate;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium bromide;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium chloride;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium iodide;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium bicarbonate;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium carbonate;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium sulfate;

2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methy ethanaminium phosphate;

tetramethyl ammonium bromide;

tetramethyl ammonium chloride;

tetramethyl ammonium iodide;

tetramethyl ammonium bicarbonate;

tetramethyl ammonium carbonate;

tetramethyl ammonium sulfate;

tetramethyl ammonium phosphate; and

mixtures thereof.