Systems and methods to assess and reduce salt levels in a mru

Patent metadata

Field	Value
Publication number	US-2025020626-A1
Application number	US-202318351994-A
Country	US
Kind code	A1
Filing date	Jul 13, 2023
Priority date	Jul 13, 2023
Publication date	Jan 16, 2025
Grant date	—

Abstract

The disclosure relates to systems and methods to assess and reduce salt levels in a monoethylene glycol (MEG) recovery unit (MRU).

First claim

What is claimed:

1 . A method, comprising:
measuring a total dissolved solid content in a monoethylene glycol (MEG)-containing stream output from a MEG recovery unit (MRU); comparing the measured total dissolved solid content to a threshold value; and when the measured total dissolved solid content is above the threshold value, flushing the MRU with a first solution comprising sodium bicarbonate and having a pH of from 4.8 to 5.3.

2 . The method of claim 1 , wherein the first solution comprises from 0.015 M to 0.1 M sodium bicarbonate.

3 . The method of claim 1 , wherein a temperature of the first solution is from 35° C. to 50° C.

4 . The method of claim 1 , further comprising flushing the MRU with the first solution a second time.

5 . The method of claim 1 , further comprising, after flushing the MRU with the first solution, flushing the MRU with a second solution having a pH of from 6.5 to 10.3.

6 . The method of claim 5 , further comprising flushing the MRU with the second solution a second time.

7 . The method of claim 1 , further comprising, prior to flushing the MRU with the first solution, mechanically removing a salt deposit from a surface of a member selected from the group consisting of the MRU and a flow line in fluid communication with the MRU.

8 . The method of claim 1 , wherein measuring the total dissolved solid content comprises measuring concentrations of barium (Ba 2+ ), calcium (Ca 2+ ), strontium (Sr 2+ ), magnesium (Mg 2+ ), sodium (Na + ), potassium (K + ), sulfate (SO 4 2− ), chloride (Cl − ), and carbonate (CO 3 2− ) output from the MRU.

9 . The method of claim 1 , wherein the threshold value is at least 15700 mg/L.

10 . The method of claim 1 , further comprising:
passing a MEG-containing stream output from a pretreatment section of the MRU through a first thermal cyclic filter, a first porous membrane filter, a second porous membrane filter and a third porous membrane filter to form a filtered stream; and inputting the filtered stream into a regeneration section of the MRU, wherein:
the first porous membrane filter is downstream of the first thermal cyclic filter;
the second porous membrane filter is downstream of the first porous membrane filter; and
the third porous membrane filter is downstream of the second porous membrane filter.

11 . The method of claim 10 , wherein:
the first porous membrane filter has a first pore size; the second porous membrane filter has a second pore size; the third porous membrane filter has a third pore size; the first pore size is larger than the second pore size; and the second pore size is larger than the third pore size.

12 . The method of claim 10 , further comprising a second thermal cyclic filter and a third thermal cyclic filter, wherein:
the second thermal cyclic filter is upstream of the second porous membrane filter and downstream of the first porous membrane filter; and the third thermal cyclic filter is upstream of the third porous membrane filter and downstream of the second porous membrane filter.

13 . A method, comprising:
flushing a monoethylene glycol recovery unit (MRU) with a first solution comprising sodium bicarbonate and a pH of 4.8 to 5.3 at a temperature of 35° C. to 50° C.

14 . The method of claim 13 , further comprising, after flushing with the first solution, flushing the MRU with a second solution comprising a pH of 6.5 to 10.3.

15 . The method of claim 13 , further comprising, prior to flushing the MRU with the first solution, mechanically removing a salt deposit from a surface of a member selected from the group consisting of the MRU and a flow line in fluid communication with the MRU.

16 . A system, comprising:
a pretreatment section configured to: i) receive a first stream comprising monoethylene glycol (MEG) and impurities comprising salt, water and hydrocarbons; ii) reduce an amount of hydrocarbons of the first stream to form a second stream having a reduced hydrocarbon content; and iii) output the second stream; a filtration section configured to: i) receive the second stream; ii) reduce an amount of one or more impurities in the second stream to form a third stream having a reduced impurity content; and iii) output the third stream; a reclamation section configured to: i) receive the third stream; ii) reduce an amount of salt in the third stream to form a fourth stream having a reduced salt content; and iii) output the fourth stream; and a regeneration section configured to: i) receive the fourth stream; ii) reduce an amount of water in the fourth stream to form a fifth stream having a reduced water content; and iii) output the fifth stream, wherein the filtration section comprises:
a first thermal cyclic filter;
a first porous membrane filter downstream of the first thermal cyclic filter;
a second porous membrane filter downstream of the first porous membrane filter;
a third porous membrane filter downstream of the second porous membrane filter; and
a first vacuum pump configured to maintain the filtration section at a first pressure.

17 . The system of claim 16 , wherein the filtration section further comprises:
a second thermal cyclic filter upstream of the second porous membrane filter and downstream of the first porous membrane filter; and a third thermal cyclic filter is upstream of the third porous membrane filter and downstream of the second porous membrane filter.

18 . The system of claim 17 , wherein:
the first porous membrane filter has a first pore size; the second porous membrane filter has a second pore size; the third porous membrane filter has a third pore size; the first pore size is larger than the second pore size; and the second pore size is larger than the third pore size.

19 . The system of claim 18 , wherein:
the first pore size is 50 μm to 100 μm; the second pore size is 5 μm to 50 μm; and the third pore size is 0.1 μm to 45 μm.

20 . The system of claim 17 , wherein the filtration section further comprises:
a first section and a second section, wherein: the first thermal cyclic filter, the first porous membrane filter, the second thermal cyclic filter and the second porous membrane filter are disposed in the first section; the first vacuum pump maintains the first section under the first pressure; the third thermal cyclic filter and the third porous membrane filter are disposed in the second section; and a second vacuum pump maintains the second section under a second pressure.

Assignees

• Saudi Arabian Oil Co

Inventors

• Oduro Harry Daniel

Classifications

• B01D2325/0283

  Pore size · CPC title

• B01D61/2461

  comprising multiple membrane extraction steps · CPC title

• B01D2317/02

  Elements in series · CPC title

• C10L3/107

  Limiting or prohibiting hydrate formation · CPC title

• C07C29/80

  by distillation · CPC title