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

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.