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

Patent metadata

Field	Value
Publication number	US-9757708-B2
Application number	US-201514973443-A
Country	US
Kind code	B2
Filing date	Dec 17, 2015
Priority date	Sep 29, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A lean MEG stream having a first pH level is contacted with a CO 2 -rich gas stream to yield a lean MEG product having a second different and lower pH level preferably in a range of 6.5 to 7.0. The system and method can be readily incorporated into a slipstream MEG recovery package, with a source of the lean 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 lean MEG product to be stored or injected.

First claim

What is claimed:

1. A MEG recovery system comprising a vessel for adjusting a pH level of a lean MEG stream exiting a MEG regeneration unit, the vessel including an inlet in fluid communication with the lean MEG stream and a port in fluid communication with a CO 2 -rich gas stream from a MEG reclamation unit, the lean MEG stream and the CO 2 -rich gas stream coming into contact with one another within the vessel, the vessel further including an outlet for a reduced pH lean MEG stream and a different outlet to vent a reduced CO 2 gas stream.

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

3. A MEG recovery system according to claim 2 wherein the amount of CO 2 -rich gas exceeds the stoichiometric quantity.

4. A MEG recovery system according to claim 1 wherein the reduced pH lean MEG stream has a pH level-of at least 6.

5. A MEG recovery system according to claim 1 wherein the reduced pH lean MEG stream has a pH level of 7.

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

7. A MEG recovery system according to claim 6 further comprising the second lean MEG stream contains less salt than the lean MEG stream.

8. A MEG recovery system according to claim 6 wherein the second lean MEG stream has a pH level of 7.

9. A MEG recovery system according to claim 1 wherein a portion of the lean MEG stream exiting the regeneration unit is routed to the MEG reclamation unit.

10. A MEG recovery system according to claim 1 wherein the vessel is a gas-liquid contactor.

11. A MEG recovery system comprising a gas/liquid contactor vessel including an inlet in fluid communication with a lean MEG stream exiting a MEG regeneration unit and a port in fluid communication with a CO 2 -rich gas stream from a MEG reclamation unit, the lean MEG stream and the CO 2 -rich gas stream coming into contact with one another within the gas/liquid contactor vessel, the gas/liquid contactor vessel further including an outlet for a reduced pH lean MEG stream and a different outlet to vent a reduced CO 2 gas stream.

Assignees

• Cameron Solutions Inc

Inventors

• Messenger Brian E

Classifications

• C07C29/94

  Use of additives, e.g. for stabilisation · CPC title

• C07C29/88

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

• B01D2252/2023

  Glycols, diols or their derivatives · CPC title

• B01D53/263

  by absorption · CPC title

• B01J2219/24

  Stationary reactors without moving elements inside · CPC title