Cyclic amine for selectively removing hydrogen sulphide

Patent metadata

Field	Value
Publication number	US-10493398-B2
Application number	US-201615764138-A
Country	US
Kind code	B2
Filing date	Sep 7, 2016
Priority date	Sep 29, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The use of an amine of the formula (I)

in which the R 1 to R 5 radicals are each as defined in the description, and an absorbent and a process for removing acidic gases from a fluid stream, especially for selectively removing hydrogen sulfide over carbon dioxide. The invention also relates to particular amines suitable for selective removal of hydrogen sulfide. Absorbents based on amines of the formula (I) have high selectivity, high loading capacity and good regeneration capacity.

First claim

The invention claimed is:

1. A process for selectively removing hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, the method comprising contacting the fluid stream with an absorbent comprising an amine of formula (I):

wherein
R 1 , R 2 , R 3 and R 4 are methyl;
R 5 is OR 10 ; and R 10 is selected from hydrogen, C 1 -C 5 -alkyl and C 2 -C 5 -hydroxyalkyl;
to obtain a treated fluid stream and a laden absorbent,
wherein the following expression is satisfied:

mol
⁡

(

H
2

⁢
S

)

mol
⁡

(

CO
2

)

⁢

⁢
in
⁢

⁢
the
⁢

⁢
laden

absorbent
⁢

⁢
at
⁢

⁢
the
⁢

⁢
bottom
⁢

⁢
of
⁢

⁢
the
⁢

⁢
absorber

mol
⁡

(

H
2

⁢
S

)

mol
⁡

(

CO
2

)

⁢

⁢
in
⁢

⁢
the
⁢

⁢
fluid
⁢

⁢
stream

>
1.

2. The process according to claim 1 , wherein the amine of the formula (I) is selected from the group consisting of:
4-hydroxy-2,2,6,6-tetramethylpiperidine,
4-ethoxy-2,2,6,6-tetramethylpiperidine,
4-propoxy-2,2,6,6-tetramethylpiperidine,
4-butoxy-2,2,6,6-tetramethylpiperidine,
4-(2′-hydroxyethoxy)-2,2,6,6-tetramethylpiperidine,
4-(3′-hydroxypropoxy)-2,2,6,6-tetramethylpiperidine and
4-(4′-hydroxybutoxy)-2,2,6,6-tetramethylpiperidine.

3. The process according to claim 1 , wherein the absorbent is an aqueous solution.

4. The process according to claim 1 , wherein the absorbent comprises at least one organic solvent.

5. The process according to claim 1 , wherein the absorbent comprises an acid having a pK A of less than 6.

6. The process according to claim 1 , wherein the absorbent comprises a tertiary amine or highly sterically hindered amine, wherein the highly sterically hindered amine comprises a tertiary carbon atom directly adjacent to a primary or secondary nitrogen atom.

7. The process according to claim 1 , wherein a residual carbon dioxide content in the treated fluid stream is at least 0.5% by volume.

8. The process according to claim 1 , wherein the laden absorbent is regenerated by at least one of the measures selected from the group consisting of heating, decompressing and stripping with an inert fluid.

Assignees

• Basf Se

Inventors

• Ingram Thomas
• Sieder Georg
• Katz Torsten
• Vorberg Gerald
• Notz Ralf

Classifications

• C10L3/102

  of acid contaminants · CPC title

• B01D2252/20436

  Cyclic amines · CPC title

• B01D2252/20478

  Alkanolamines · CPC title

• B01D2256/245

  Methane · CPC title

• C10L2290/542

  Adsorption of impurities during preparation or upgrading of a fuel · CPC title