Use of extended surfactants in process membrane cleaning

Patent metadata

Field	Value
Publication number	US-11291958-B2
Application number	US-201816122418-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Sep 29, 2017
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

Disclosed are membrane separation cleaning processes and clean in place compositions for such membranes. The cleaning compositions can remove proteins, fats, and other food, beverage, and brewery based soils and offer an environmentally friendly alternative surfactant system to NPE. Branched extended chain PO/EO nonionic surfactants with certain characteristics may be used to provide superior cleaning to membranes. The specific surfactants may be used alone or in combination. In some embodiments, the surfactant package is used as part of a cleaning composition.

First claim

What is claimed is:

1. A method for cleaning a membrane filter system comprising:
washing a membrane with a composition comprising a surfactant comprising one or more branched extended nonionic surfactants with a contact angle of less than 20 degrees, and a cloud point of 50° C. or higher,
wherein said branched extended nonionic surfactant comprises a surfactant booster having the following formula:
R-[L] x -[O—CH 2 -CH 2 ] y

where R is a branched, saturated or unsaturated, substituted or unsubstituted, aliphatic or aromatic hydrocarbon radical having from about 8 to 20 carbon atoms, L is a propylene oxide (PO) linking group, x is the chain length of the linking group ranging from 2-25, and y is the average degree of ethoxylation ranging from 2 to 20.

2. The method according to claim 1 , wherein the membrane is fouled with a food, water, beverage, or brewery product.

3. The method according to claim 1 , wherein the membrane is fouled with a dairy product.

4. The method according to claim 1 wherein said surfactant booster has an R group of ethyl hexyl.

5. The method according to claim 4 wherein said surfactant booster has an R group of 2 ethyl hexyl.

6. The method according to claim 1 wherein x is 5.

7. The method according to claim 1 wherein said y is 6 or 9.

8. The method according to claim 1 wherein said branched extended nonionic surfactant further comprises a Guerbet alcohol.

9. The method according to claim 8 wherein said Guerbet alcohol is a 3 propyl heptanol C 10 -(PO) a (EO) b series, where a is 1.0 to 1.5, b is 4 to 14, PO is propylene oxide, and EO is ethylene oxide.

10. The method according to claim 1 wherein said membrane is a polyethersulfone membrane.

11. The method according to claim 1 wherein said membrane is a polyvinylidene fluoride membrane.

12. The method according to claim 1 wherein said membrane is a polyamide and/or thin film composite membrane.

13. The method according to claim 1 wherein said membrane is a ceramic membrane.

14. The method according to claim 1 wherein said membrane is a stainless steel membrane.

15. The method according to claim 1 wherein said composition has an interfacial tension of less than 7 mN/m.

16. The method according to claim 1 , further comprising washing said membrane with a source of alkalinity.

17. The method according to claim 16 wherein said washing of said membrane with a source of alkalinity occurs prior to, simultaneous with or after said washing of said membrane with said surfactant.

18. The method according to claim 1 wherein said method does not include the application of nonyl phenol ethoxylates (NPE) to said membrane.

19. A method of cleaning a filtration membrane comprising:
applying to said membrane a cleaning composition comprising;
a source of alkalinity; and
one or more branched extended nonionic surfactants with a contact angle of less than 20 degrees, a cloud point of 50° C. or higher wherein said branched extended nonionic surfactant comprises a surfactant booster having the following formula:
R-[L] x -[O—CH 2 -CH 2 ] y

where R is a branched, saturated or unsaturated, substituted or unsubstituted, aliphatic or aromatic hydrocarbon radical having from about 8 to 20 carbon atoms, L is a propylene oxide (PO) linking group, x is the chain length of the linking group ranging from 2-25, and y is the average degree of ethoxylation ranging from 2 to 20 and thereafter,
rinsing said membrane, wherein said cleaning composition is NPE free.

20. The method according to claim 19 wherein said extended surfactant has an R group of 2 ethyl hexyl.

21. The method according to claim 19 wherein x is 5.

22. The method according to claim 19 wherein said y is 6 or 9.

23. The method according to claim 19 wherein said cleaning composition further comprises a Guerbet alcohol.

24. The method according to any of claim 23 wherein said Guerbet alcohol is a 3 propyl heptanol C 10 -(PO) a (EO) b series, where a is 1.0 to 1.5, and b is 4 to 14.

25. The method according to claim 19 wherein said membrane is a polyethersulfone membrane.

26. The method according to claim 19 wherein said membrane is a polyvinylidene fluoride membrane.

27. The method according to claim 19 wherein said membrane is a polyamide and/or thin film composite membrane.

28. The method according to claim 19 wherein said membrane is a ceramic membrane.

29. The method according to claim 19 wherein said membrane is a stainless steel membrane.

30. The method according to claim 19 wherein said composition has an interfacial tension of less than 7 mN/m.

31. A method of cleaning a filtration membrane comprising:
Mixing water with one or more branched extended nonionic surfactants with a contact angle of less than 20 degrees, a cloud point of 50° C. or higher wherein said branched extended nonionic surfactant comprises a surfactant booster having the following formula:
R-[L] x -[O—CH 2 -CH 2 ] y

where R is a branched, saturated or unsaturated, substituted or unsubstituted, aliphatic or aromatic hydrocarbon radical having from about 8 to 20 carbon atoms, L is a propylene oxide (PO) linking group, x is the chain length of the linking group ranging from 2-25, and y is the average degree of ethoxylation ranging from 2 to 20 and thereafter,
flushing said membrane with water and said surfactant mixture.

32. The method according to claim 31 wherein said extended surfactant has an R group of 2 ethyl hexyl.

33. The method according to of claim 31 wherein x is 5.

34. The method according to claim 31 wherein said y is 6 or 9.

35. The method according to claim 31 wherein said cleaning composition further comprises a Guerbet alcohol.

36. The method according to claim 31 wherein said membrane is a polyvinylidene fluoride membrane.

Assignees

• Ecolab Usa Inc

Inventors

• Schacht Paul Frazer
• Power Caleb
• Lascotte Keith G
• Irey Elizabeth
• Soontravanich Sukhwan

Classifications

• B01D65/02 Primary

  Membrane cleaning or sterilisation {; Membrane regeneration} · CPC title

• B01D2321/164

  Use of bases · CPC title

• B01D2321/168

  Use of other chemical agents · CPC title

• B01D71/34

  Polyvinylidene fluoride · CPC title

• A23C2210/20

  Treatment using membranes, including sterile filtration · CPC title