System and method for pH control of lean MEG product from MEG regeneration and reclamation packages

Patent metadata

Field	Value
Publication number	US-10232340-B2
Application number	US-201715700859-A
Country	US
Kind code	B2
Filing date	Sep 11, 2017
Priority date	Sep 29, 2014
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A MEG stream having a first pH level is contacted with a CO 2 -rich gas stream to yield a MEG product having a second different and lower pH level. The system and method can be readily incorporated into a slipstream MEG recovery package, with a source of the MEG stream being a MEG regeneration section of the package. The CO 2 -rich gas could be a vented CO 2 stream from the MEG reclamation section of the package. Unlike hydrochloric and acetic acid overdosing, CO 2 overdosing of the lean MEG stream does not lead to rapid acidification of the MEG product to be stored or injected.

First claim

What is claimed:

1. A MEG recovery vessel including:
an inlet in fluid communication with a MEG stream exiting a MEG treatment, the MEG stream having a first pH level;
a port in fluid communication with a gas stream, the gas stream containing more than 50% CO 2 ;
an outlet for the MEG stream after contact with the gas stream; and
a vent for the gas stream after contact with the MEG stream;

wherein the MEG stream after contact with the gas stream has a second pH level lower than the first pH level; and
wherein the gas stream after contact with the MEG stream has a lowered CO 2 content.

2. A MEG recovery vessel according to claim 1 wherein an amount of CO 2 in the gas stream is at least equal to a stoichiometric quantity effective for achieving a reduced pH level of the MEG stream.

3. A MEG recovery vessel according to claim 1 wherein an amount of CO 2 in the gas stream is greater than a stoichiometric quantity effective for achieving a reduced pH level of the MEG stream.

4. A MEG recovery system according to claim 1 wherein the second lower pH level is at least 6.

5. A MEG recovery vessel according to claim 1 wherein the second lower pH level is 7.

6. A MEG recovery vessel according to claim 1 wherein the MEG stream is mixed with a second MEG stream having a different pH level than the first pH level.

7. A MEG recovery vessel according to claim 6 wherein the different pH level is 7.

8. A MEG recovery vessel according to claim 1 wherein the MEG stream is mixed with a second MEG stream having a different salt content than that of the MEG stream.

9. A MEG recovery vessel according to claim 1 wherein the MEG treatment includes a MEG regeneration unit.

10. A MEG recovery vessel according to claim 1 wherein the gas stream is from a MEG reclamation unit.

11. A MEG recovery vessel according to claim 1 wherein the MEG treatment lowers a non-MEG content of a mixture containing the MEG stream.

12. A MEG recovery gas/liquid contactor vessel comprising:
an inlet in fluid communication with a MEG stream exiting a MEG treatment;
a port in fluid communication with a gas stream containing more than 50% CO 2 ;
an outlet for a reduced pH MEG stream; and
a different outlet to vent a reduced CO 2 gas stream;

wherein the MEG stream and the gas stream come into contact with one another within the gas/liquid contactor vessel.

13. A method for pH control of a MEG stream, the method comprising:
contacting a MEG stream with a gas stream, the MEG stream being from a MEG treatment, the gas stream containing more than 50% CO 2 .

14. A method according to claim 13 wherein an amount of CO 2 in the gas stream is at least equal to a stoichiometric quantity effective for achieving a reduced pH level of the MEG stream.

15. A method according to claim 13 wherein an amount of CO 2 in the gas stream is a stoichiometric quantity effective for achieving a reduced pH level of the MEG stream.

16. A method according to claim 13 further comprising mixing the MEG stream with a second MEG stream having a different pH level than that of the MEG stream.

17. A method according to claim 13 further comprising mixing the MEG stream with a second MEG stream having a different salt content than that of the MEG stream.

18. A method according to claim 13 wherein a pH level the MEG stream is at least 6 after contact with the gas stream.

19. A method according to claim 13 wherein the MEG treatment includes a MEG regeneration unit.

20. A method according to claim 13 wherein the gas stream is from a MEG reclamation unit.

21. A method according to claim 13 wherein the MEG treatment lowers a non-MEG content of a mixture containing the MEG stream.

Assignees

• Cameron Solutions Inc

Inventors

• Messenger Brian E

Classifications

• C07C29/88

  by treatment giving rise to a chemical modification of at least one compound (chemisorption C07C29/76) · CPC title

• C09K2208/22

  Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers · CPC title

• C09K8/52

  Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning · CPC title

• C07C31/202

  Ethylene glycol · CPC title

• B01D2252/2023

  Glycols, diols or their derivatives · CPC title