Surfactant removal from produced waters

Patent metadata

Field	Value
Publication number	US-10501340-B2
Application number	US-201615189590-A
Country	US
Kind code	B2
Filing date	Jun 22, 2016
Priority date	Jun 22, 2015
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A method for removing a surfactant from a water stream includes contacting the water stream with a particulate support having a hydrous iron oxide coating to provide a treated water stream. The treated water stream has less surfactant than the water stream.

First claim

The invention claimed is:

1. A method for removing a surfactant from a water stream, the method consisting essentially of:
providing a water stream comprising produced water containing surfactant recovered from an oil well,
contacting the water stream with a particulate support comprising sand with a hydrous iron oxide coating,
absorbing said surfactant to said hydrous iron oxide coating to provide a surfactant-iron-sand complex, and
separating the water stream from said particulate support to thereby provide a treated water stream comprising less surfactant than the water stream.

2. The method of claim 1 , wherein said hydrous iron oxide coating is formed by adding a hydrous iron oxide precursor to the water stream to form the hydrous iron oxide coating.

3. The method of claim 1 , wherein the particulate support is a bed of moving sand.

4. The method of claim 1 , wherein the treated water stream has less than 1 wt. % residual surfactant.

5. The method of claim 1 , wherein said surfactant is at least partially degraded.

6. The method of claim 3 , wherein said surfactant is at least partially degraded and adsorbing the degraded surfactant to the hydrous iron oxide coating to provide a degraded surfactant-iron-sand complex.

7. The method of claim 1 , wherein the surfactant of the surfactant-iron-sand complex is at least partially degraded.

8. The method of claim 1 , wherein the separating is by gravity separating, filtering, centrifuging, decanting, or a combination comprising at least one of the foregoing separating methods, preferably by gravity separating.

9. The method of claim 1 , wherein the surfactant is present in the water stream in an amount of 50 to 400 ppm.

10. The method of claim 1 , wherein the surfactant is an anionic surfactant.

11. The method of claim 10 , wherein the anionic surfactant comprises a C4-25 alkyl sulfonate, a C6-25 alkylaryl sulfonate, a C4-25 alkyl sulfate, or a salt thereof, or a combination comprising at least one of the foregoing.

12. The method of claim 1 , wherein the surfactant comprises dodecylsulfate or an alkali metal salt thereof.

13. The method of claim 2 , wherein the hydrous iron oxide precursor comprises ferric chloride, ferrous chloride, ferric sulfate, ferrous sulfate, or a combination comprising at least one of the foregoing.

14. The method of claim 3 , wherein the contacting comprises passing the water through the bed of moving sand.

15. The method of claim 2 , wherein the hydrous iron oxide precursor is present in the water stream at a hydrous iron oxide precursor:surfactant molar ratio of 0.25:1 to 5:1.

16. The method of claim 2 , wherein
the water stream is a produced water stream recovered from an oil well;
the hydrous iron oxide precursor comprises ferric chloride; and
the surfactant is an anionic surfactant in an amount of 50 to 400 ppm.

17. The method of claim 2 , comprising oxidizing the water stream prior to introducing the hydrous iron oxide precursor to the water stream.

Assignees

• Conocophillips Co

Inventors

• Needham Riley B
• SOLAIRAJ Sriram

Classifications

• C02F2101/301

  Detergents, surfactants · CPC title

• C02F1/72

  by oxidation {(C02F1/4672 takes precedence)} · CPC title

• C02F1/288

  using composite sorbents, e.g. coated, impregnated, multi-layered · CPC title

• C02F2103/10

  from quarries or from mining activities · CPC title

• B01J20/3236

  containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts · CPC title