Method and compositions for inhibition of naphthenic acid induced corrosion

Patent metadata

Field	Value
Publication number	US-9719035-B2
Application number	US-201313925535-A
Country	US
Kind code	B2
Filing date	Jun 24, 2013
Priority date	Jun 30, 2006
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Corrosion induced by the presence of naphthenic acids in hydrocarbon fluids, particularly where such fluids are at elevated temperatures, may be inhibited or controlled through use of corrosion inhibiting compositions comprising a combination of a minor portion of a phosphorus-based constituent and a major portion of a sulfur-based constituent, nitrogen-based constituent, or combination thereof. In another embodiment the sulfur-based constituent and/or nitrogen-based constituent may be used without any phosphorus-based constituent. Where the compounds are appropriately selected, the compositions may inhibit corrosion to a degree comparable or nearly comparable to the inhibition provided by an equal amount of some conventional phosphorus-based compounds alone, but are significantly less likely to impair catalyst activity in downstream cracking and refinery operations.

First claim

We claim:

1. A method for inhibiting naphthenic acid corrosion of metals in hydrocarbon fluids comprising adding to a non-aqueous hydrocarbon fluid, in an amount sufficient to inhibit corrosion therein, a corrosion inhibitor composition comprising:
a phosphorus-based constituent comprising at least one compound selected from the group consisting of:
a. thiophosphorus compounds of the formula

wherein R 1 is R 3 (OCH 2 CH 2 ) n or R 3 (OCH 2 CH 2 ) n O; R 2 is the same as R 1 or XH, each X being independently sulfur or oxygen; provided however that at least one X is sulfur; R 3 is an alkyl group of from about 6 to about 18 carbon atoms; and n is an integer of from about 0 to about 12;
b. salts of the thiophosphorus compounds;
c. alkyl and aryl esters of the thiophosphorus compounds; and
d. isomers of the thiophosphorus compounds; and
e. phosphate ester compounds;
a sulfur-based constituent that is 1,2,4-dithiazole-3-thione; and
a nitrogen-based constituent selected from the group consisting of acridine, phenanthridine, octahydrophenanthridine, and combinations thereof;
provided that the phosphorus-based constituent is present in minor portion.

2. The method of claim 1 wherein the temperature of the hydrocarbon fluid is from about 175° C. to 400° C.

3. The method of claim 1 wherein the amount of the inhibitor composition is from about 10 ppm to about 5,000 ppm.

4. A composition for inhibiting or controlling naphthenic acid induced corrosion in a non-aqueous hydrocarbon fluid comprising:
a phosphorus-based constituent comprising at least one compound selected from the group consisting of:
a. thiophosphorus compounds of the formula

wherein R 1 is R 3 (OCH 2 CH 2 ) n or R 3 (OCH 2 CH 2 ) n O; R 2 is the same as R 1 or XH, each X being independently sulfur or oxygen; provided however that at least one X is sulfur; R 3 is an alkyl group of from about 6 to about 18 carbon atoms; and n is an integer of from about 0 to about 12;
b. salts of the thiophosphorus compounds;
c. alkyl and aryl esters of the thiophosphorus compounds; and
d. isomers of the thiophosphorus compounds; and
e. phosphate ester compounds;
a sulfur-based constituent that is 1,2,4-dithiazole-3-thione; and
a nitrogen-based constituent comprising at least one compound conforming to one of the following formulas:

wherein R is —H, —SH, —SR, —SSR, or C1-C12 normal or partially or fully branched alkyl that is saturated or unsaturated;
provided that the phosphorus-based constituent is present in minor portion;
where the composition is capable of inhibiting or controlling naphthenic acid induced corrosion in a non-aqueous hydrocarbon fluid.

5. The composition of claim 4 wherein the minor portion is no more than about 40 percent by weight of the composition.

6. The composition of claim 5 wherein the minor portion is no more than about 30 percent by weight of the composition.

7. The composition of claim 4 wherein the nitrogen-based constituent is selected from the group consisting of acridine, phenanthridine, octahydrophenanthridine, 1,3-thiazole, and combinations thereof.

8. A composition for inhibiting or controlling naphthenic acid induced corrosion in a non-aqueous hydrocarbon fluid where the composition comprises:
a sulfur-based constituent that is 1,2,4-dithiazole-3-thione; and
a nitrogen-based constituent selected from the group consisting of acridine, phenanthridine, octahydrophenanthridine, 1,3-thiazole, and combinations thereof;
wherein the composition is present in major portion and where the composition is capable of inhibiting or controlling naphthenic acid induced corrosion in a non-aqueous hydrocarbon fluid.

Assignees

• Baker Hughes Inc

Inventors

• Zetlmeisl Michael J
• Harrell Bradley G
• Borgard Bradley G
• Bieber Scott

Classifications

• C10G2300/203

  Naphthenic acids, TAN · CPC title

• C07C7/20

  Use of additives, e.g. for stabilisation · CPC title

• C09K15/12

  containing sulfur and oxygen · CPC title

• C10G2300/4075

  Limiting deterioration of equipment · CPC title

• C10G7/10 Primary

  Inhibiting corrosion during distillation · CPC title