Absorbent and process for selectively removing hydrogen sulfide

Patent metadata

Field	Value
Publication number	US-11458433-B2
Application number	US-201816643665-A
Country	US
Kind code	B2
Filing date	Aug 30, 2018
Priority date	Sep 4, 2017
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

An absorbent for the selective removal of hydrogen sulfide over carbon dioxide from a fluid stream, wherein the absorbent contains an aqueous solution, comprising an amine of formula (I) and/or an amine of formula (II) wherein U—V—W is CH—O—CHR5, N—CO—CHR5 or N—CO—NR5; U′—V′—W is C—O—CR5; R1 is independently C1-C5-alkyl; R2 is selected from hydrogen and C1-C5-alkyl; R3 is independently selected from hydrogen and C1-C5-alkyl; R4 is independently selected from hydrogen and C1-C5-alkyl; R5 is selected from hydrogen, C1-C5-alkyl, (C1-C5-alkoxy)-C1-C5-alkyl, and hydroxy-C1-C5-alkyl; and x is an integer from 1 to 10. The absorbent has a reduced tendency for phase separation at temperatures falling within the usual range of regeneration temperatures for the aqueous amine mixtures and a low volatility in aqueous solvents.

First claim

The invention claimed is:

1. A process for the selective removal of hydrogen sulfide over carbon dioxide from a fluid stream, comprising contacting the fluid stream with an absorbent containing an aqueous solution, comprising an amine of formula (I)

wherein
U—V—W is N—CO—CHR 5 ;
R 1 is independently C 1 -C 5 -alkyl;
R 2 is selected from hydrogen and C 1 -C 5 -alkyl;
R 3 is independently selected from hydrogen and C 1 -C 5 -alkyl;
R 4 is independently selected from hydrogen and C 1 -C 5 -alkyl;
R 5 is selected from hydrogen, C 1 -C 5 -alkyl, (C 1 -C 5 -alkoxy)-C 1 -C 5 -alkyl, and hydroxy-C 1 -C 5 -alkyl; and
x is an integer from 1 to 10,
wherein the absorbent comprises a total amount of 15% to 70% by weight of amine of formula (I), based on the total weight of the absorbent,

and obtaining a laden absorbent and a treated fluid stream.

2. The process according to claim 1 , wherein the
amine is selected from 1[2-(tert-butylamino)ethyl]pyrrolidin-2-one, 1-[2-(tert-butylamino)propyl]pyrrolidin-2-one,
1-[2-(isopropylamino)ethyl]pyrrolidin-2-one,
and

1-[2-(isopropylamino)propyl]pyrrolidin-2-one.

3. The process according to claim 2 , wherein the amine is selected from 1-[2-(tert-butylamino)ethyl]pyrrolidin-2-one, and 1-[2-(isopropylamino)ethyl]pyrrolidin-2-one.

4. The absorbent according to claim 3 , wherein the amine is 1-[2-(tert-butylamino)-ethyl]pyrrolidin-2-one.

5. The process according to claim 1 , wherein the absorbent additionally comprises an acid.

6. The process according to claim 1 , wherein the absorbent additionally comprises a tertiary amine and/or severely sterically hindered amine other than the compounds of the general formula (I), wherein severe steric hindrance is understood to mean a tertiary carbon atom directly adjacent to a primary or secondary nitrogen atom.

7. The process according to claim 1 , wherein the absorbent comprises a non-aqueous organic solvent.

8. The process according to claim 7 , wherein the non-aqueous organic solvent is selected from C 4-10 alcohols, ketones, esters, lactones, amides, lactams, sulfones, sulfoxides, glycols, polyalkylene glycols, di- or mono(C 1 -C 4 -alkyl ether) glycols, di- or mono(C 1 -C 4 -alkyl ether) polyalkylene glycols, cyclic ureas, thioalkanols and mixtures thereof.

9. The process according to claim 1 , further comprising regenerating the laden absorbent by heating, decompressing or stripping with an inert fluid.

Assignees

• Basf Se
• Exxonmobil Res & Eng Co

Inventors

• Ernst Martin
• Vorberg Gerald
• Ingram Thomas
• Sieder Georg
• Pereira Carla

Classifications

• B01D53/1468

  Removing hydrogen sulfide · CPC title

• B01D2252/20426

  Secondary amines · CPC title

• B01D2256/245

  Methane · CPC title

• B01D2252/20468

  containing a pyrrolidone-ring · CPC title

• B01D53/1493 Primary

  Selection of liquid materials for use as absorbents · CPC title