Methods of using ionic liquid based asphaltene inhibitors

1. A method of enhancing the performance of an asphaltene inhibitor during production, storage, transportation or refining of a petroleum hydrocarbon fluid, wherein the asphaltene inhibitor is a phenol aldehyde resin of the structure:

(a)

wherein R is —H or a C 1-20 linear or branched alkyl and n is greater than 2; or

(b)

wherein R 5 is a C 1-20 linear or branched alkyl, R 6 is different from R 5 and is H or a linear or branched C 1-20 alkyl, and n and m are greater than 1,

the method comprising contacting the asphaltene inhibitor with an ionic liquid during a production or refining operation or prior to or during storage or transportation of the petroleum hydrocarbon fluid, wherein the ionic liquid has a cation of R 1 R 2 R 3 R 4 N + or R 1 R 2 R 3 N + R 8 N + R 5 R 6 R 7 and an anion, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from hydrogen, a straight or branched C 1-30 alkyl group, benzyl, a C 7-30 alkylbenzyl group, a C 7-30 arylalkyl group, a straight or branched C 3-30 alkenyl group, a C 1-30 hydroxyalkyl group, a C 7-30 hydroxyalkylbenzyl group, an oxyalkylene or a polyoxyalkylene group or a zwitterion; R 8 is a straight or branched C 1-30 alkylene, an alkylene oxyalkylene or an alkylene polyoxyalkylene; and the anion comprises halides, hydroxyl, bicarbonate, carbonate, alkyl carbonates, alkoxides, carboxylates, hydroxycarboxylates or a combination thereof.

2. The method of claim 1 , wherein at least one of the following conditions prevail:

(a) R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is —H or a C 1-20 alkyl;

(b) the oxyalkylene is of the formula HO—R 11 — where R 11 is a C 2 -C 10 alkylene group;

(c) the polyoxyalkylene group is of the formula H—[O—R 10 —] z , or H(O—R 11 ) x —[O—R 11 —] y where each occurrence of R 10 or R 11 is independently a C 1-10 alkylene, z is an integer greater than 1 and x and y are independently selected from 1 to 1500;

(d) the alkylene polyoxyalkylene group is of the formula (a) —R 12 —[O—R 13 —] y , wherein R 12 is a C 1-30 alkylene, each occurrence of R 13 is independently a C 1-10 alkylene, and y is an integer from 1 to 500; or (b) —R 14 —O—R 15 —;

(e) the alkylene oxyalkylene group is of the formula —R 14 —O—R 15 —, wherein R 14 and R 15 are each independently a C 1-20 , branched or straight chain alkylene;

(f) the weight ratio of the asphaltene inhibitor relative to the ionic liquid is about 99:1 to about 3:1; or

the asphaltene inhibitor is combined with an organic metal salt.

3. The method of claim 1 , wherein the asphaltene inhibitor further contains an amine or polyamine additive.

4. The method of claim 3 , wherein the amine or polyamine additive is selected from the group consisting of fatty acid based imidazolines, diethylenetriamine, tetraethylenetetramine, tetraethylenepentamine, or a combination thereof.

5. The method of claim 1 , wherein R 5 is a C 7-16 linear or branched alkyl and R 6 is a C 1-6 linear or branched alkyl.

6. The method of claim 1 , wherein the ionic liquid and the asphaltene inhibitor form a complex, a synergistic mixture or a reaction product.

7. The method of claim 1 , wherein the ionic liquid comprises dicocodimethyl ammonium hydroxide, ditallowdimethyl ammonium hydroxide, tributylmethylammonium methyl carbonate, tetraethylammonium bicarbonate, tetrabutylammonium hydroxide, tallowtrimethyl ammonium hydroxide, cocotrimethyl ammonium hydroxide, hydrogenated tallow trimethyl ammonium hydroxide, dihydrogenated tallow dimethyl ammonium hydroxide, oxydiethylene bis(cocodimethylammonium hydroxide), or a combination thereof.

8. The method of claim 1 , wherein the anion is a hydroxide, carbonate or bicarbonate.

9. The method of claim 1 , wherein the anion is a carboxylate, hydroxycarboxylate, a Cis fatty acid, an alkoxide or a combination thereof.

10. A method of inhibiting, reducing or preventing the formation, agglomeration and/or accumulation of asphaltene deposits or inhibiting, preventing or reducing precipitation of asphaltene from a petroleum hydrocarbon fluid (a) in an underground reservoir; (b) onto a conduit or vessel; or (iii) in a refinery by contacting the fluid with a composition comprising:

(A) an asphaltene inhibitor of a phenol aldehyde resin of the structure:

(i)

wherein R is —H or a C 1-20 linear or branched alkyl and n is greater than 2; or

(ii)

wherein R 5 is a C 1-20 linear or branched alkyl, R 6 is different from R 5 and is H or a linear or branched C 1-20 alkyl, and n and m are greater than 1, and

(B) an ionic liquid comprising a cation of R 1 R 2 R 3 R 4 N + or R 1 R 2 R 3 N + R 8 N + R 5 R 6 R 7 and an anion, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from hydrogen, a straight or branched C 1-30 alkyl group, benzyl, a C 7-30 alkylbenzyl group, a C 7-30 arylalkyl group, a straight or branched C 3-30 alkenyl group, a C 1-30 hydroxyalkyl group, a C 7-30 hydroxyalkylbenzyl group, an oxyalkylene or a polyoxyalkylene group or a zwitterion; R 8 is a straight or branched C 1-30 alkylene, an alkylene oxyalkylene or an alkylene polyoxyalkylene; and the anion comprises halides, hydroxyl, bicarbonate, carbonate, alkyl carbonates, alkoxides, carboxylates, hydroxycarboxylates or a combination thereof.

11. The method of claim 10 , wherein at least one of the following conditions prevail:

(a) R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is —H or a C 1-20 alkyl;

(b) the oxyalkylene is of the formula HO—R 11 — where R 11 is a C 2 -C 10 alkylene group;

(c) the polyoxyalkylene group is of the formula H—[O—R 10 —] z , or H(O—R 11 ) x —[O—R 11 —] y where each occurrence of R 10 or R 11 is independently a C 1-10 alkylene, z is an integer greater than 1 and x and y are independently selected from 1 to 1500;

(d) the alkylene polyoxyalkylene group is of the formula (a) —R 12 —[O—R 13 —] y , wherein R 12 is a C 1-30 alkylene, each occurrence of R 13 is independently a C 1-10 alkylene, and y is an integer from 1 to 500; or (b) —R 14 —O—R 15 —;

(e) the alkylene oxyalkylene group is of the formula —R 14 —O—R 15 —, wherein R 14 and R 15 are each independently a C 1-20 , branched or straight chain alkylene;

(f) the weight ratio of the asphaltene inhibitor relative to the ionic liquid is about 99:1 to about 3:1; or

the asphaltene inhibitor is combined with an organic metal salt.

12. The method of claim 10 , wherein the asphaltene inhibitor further contains an amine or polyamine additive.

13. The method of claim 12 , wherein the amine or polyamine additive is selected from the group consisting of fatty acid based imidazolines, diethylenetriamine, tetraethylenetetramine, tetraethylenepentamine, or a combination thereof.

14. The method of claim 10 , wherein R 5 is a C 7-16 linear or branched alkyl and R 6 is a C 1-6 linear or branched alkyl.

15. The method of claim 10 , wherein the ionic liquid comprises dicocodimethyl ammonium hydroxide, ditallowdimethyl ammonium hydroxide, tributylmethylammonium methyl carbonate, tetraethylammonium bicarbonate, tetrabutylammonium hydroxide, tallowtrimethyl ammonium hydroxide, cocotrimethyl ammonium hydroxide, hydrogenated tallow trimethyl ammonium hydroxide, dihydrogenated tallow dimethyl ammonium hydroxide, oxydiethylene bis(cocodimethylammonium hydroxide), or a combination thereof.

16. The method of claim 10 , wherein the ionic liquid and the asphaltene inhibitor form a complex, a synergistic mixture or a reaction product.

17. The method of claim 10 , wherein the anion is a carboxylate, hydroxycarboxylate, a C 18 fatty acid, an alkoxide or a combination thereof.

18. A method of treating a petroleum hydrocarbon fluid, the method comprising: contacting the petroleum hydrocarbon fluid with:

(I) a phenol aldehyde resin of the structure:

a)

wherein R is —H or a C 1-20 linear or branched alkyl and n is greater than 2; or

(b)

wherein R 5 is a C 1-20 linear or branched alkyl, R 6 is different from R 5 and is H or a linear or branched C 1-20 alkyl, and n and m are greater than 1; and

(II) an ionic liquid having a cation of R 1 R 2 R 3 R 4 N + or R 1 R 2 R 3 N + R 8 N + R 5 R 6 R 7 and an anion, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from hydrogen, a straight or branched C 1-30 alkyl group, benzyl, a C 7-30 alkylbenzyl group, a C 7-30 arylalkyl group, a straight or branched C 3-30 alkenyl group, a C 1-30 hydroxyalkyl group, a C 7-30 hydroxyalkylbenzyl group, an oxyalkylene or a polyoxyalkylene group or a zwitterion; R 8 is a straight or branched C 1-30 alkylene, an alkylene oxyalkylene or an alkylene polyoxyalkylene; and the anion comprise, hydroxyl, bicarbonate, carbonate, alkyl carbonates, alkoxides, carboxylates, hydroxycarboxylates or a combination thereof.

19. The method of claim 18 , wherein at least one of the following conditions prevail:

(a) R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is —H or a C 1-20 alkyl;

(b) the oxyalkylene is of the formula HO—R 11 — where R 11 is a C 2 -C 10 alkylene group;

(c) the polyoxyalkylene group is of the formula H—[O—R 10 —] z , or H(O—R 11 ) x —[O—R 11 —] y where each occurrence of R 10 or R 11 is independently a C 1-10 alkylene, z is an integer greater than 1 and x and y are independently selected from 1 to 1500;

(d) the alkylene polyoxyalkylene group is of the formula (a) —R 12 —[O—R 13 —] y , wherein R 12 is a C 1-30 alkylene, each occurrence of R 13 is independently a C 1-10 alkylene, and y is an integer from 1 to 500; or (b) —R 14 —O—R 15 —;

(e) the alkylene oxyalkylene group is of the formula —R 14 —O—R 15 —, wherein R 14 and R 15 are each independently a C 1-20 , branched or straight chain alkylene; or

(f) the weight ratio of the asphaltene inhibitor relative to the ionic liquid is about 99:1 to about 3:1;

(g) the asphaltene inhibitor is combined with an organic metal salt.

20. The method of claim 18 , wherein the asphaltene inhibitor further contains an amine or polyamine additive.

21. The method of claim 18 , wherein the ionic liquid and the phenol aldehyde resin form a complex, a synergistic mixture or a reaction product.

22. The method of claim 21 , wherein the ionic liquid and the asphaltene inhibitor form a complex or synergistic mixture and wherein the weight ratio of the asphaltene inhibitor to the ionic liquid in the complex or synergistic mixture is about 5:95 to about 3:1.

23. The method of claim 18 , wherein the ionic liquid comprises dicocodimethyl ammonium hydroxide, ditallowdimethyl ammonium hydroxide, tributylmethylammonium methyl carbonate, tetraethylammonium bicarbonate, tetrabutylammonium hydroxide, tallowtrimethyl ammonium hydroxide, cocotrimethyl ammonium hydroxide, hydrogenated tallow trimethyl ammonium hydroxide, dihydrogenated tallow dimethyl ammonium hydroxide, oxydiethylene bis(cocodimethylammonium hydroxide), or a combination thereof.

24. The method of claim 18 , wherein the anion is a carboxylate, hydroxycarboxylate, a C 18 fatty acid, an alkoxide or a combination thereof.

25. The method of claim 18 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is —H or a C 1-20 alkyl.

26. The method of claim 18 , wherein the polyoxyalkylene group is of the formula H—[O—R 10 —] z , where each occurrence of R 10 is independently a C 1-10 alkylene and z is an integer greater than 1.