Cationic ammonium surfactants as low dosage hydrate inhibitors
View Patent ↗This disclosure relates to anti-agglomerant low dosage hydrate inhibitors that can inhibit the formation of hydrate agglomerants and/or plugs. The anti-agglomerant low dosage hydrate inhibitors can be surfactants. The hydrate inhibitors can be used for inhibiting, retarding, mitigating, reducing, controlling and/or delaying formation of hydrocarbon hydrates, agglomerants of hydrates, and/or plugs. The hydrate inhibitors can be applied to prevent, reduce, and/or mitigate plugging of conduits, pipes, transfer lines, valves, and other places or equipment where hydrocarbon hydrate solids can form. The hydrate inhibitors can be zwitterionic or cationic ammonium surfactants.
1. A hydrate inhibitor composition comprising a hydrate-inhibiting effective amount of a compound of Formula (I), or an acid, a free base, a zwitterion, or a salt thereof:
wherein
R 1 is hydrogen, a C 1 to C 20 substituted or unsubstituted alkyl group, or a C 1 to C 20 substituted or unsubstituted alkenyl group;
R 2 is an alkylcarboxyl, or an alkylamido group;
R 4 is hydrogen, a C 1 to C 20 substituted or unsubstituted alkyl group, or a C 1 to C 20 substituted or unsubstituted alkenyl group;
R 5 is C 10 to C 20 alkyl or —R 50 —NR 6 R 7 , wherein R 50 is C 1 to C 5 alkylene, and R 6 and R 7 are independently C 1 to C 6 alkyl; and
R 8 is a C 2 to C 10 substituted or unsubstituted alkylene group.
2. The composition of claim 1 , wherein the substituted alkyl group of R 1 and R 4 has at least one of the —CH 2 — groups in the chain replaced with an ether, an amine, an amide, a carbonyl, or an ester functional group or at least one of the hydrogen atoms attached to a carbon atom of the chain is replaced with a hydroxy, a halo, or an amine group.
3. The composition of claim 2 , wherein the substituted alkyl group of R 1 and R 4 has at least one of the —CH 2 — groups in the chain replaced with an amine.
4. The composition of claim 1 , wherein R 8 is —C 2 H 4 —.
5. The composition of claim 4 , wherein R 1 is C 10 to C 20 alkyl or —R 10 —NR 6 R 7 , wherein R 10 is C 1 to C 5 alkylene, and R 6 and R 7 are independently substituted or unsubstituted C 1 to C 6 alkyl.
6. The composition of claim 1 , wherein R 2 is —R 20 —C(O)O − , wherein R 20 is C 1 to C 4 alkylene.
7. The composition of claim 1 , wherein R 4 is hydrogen.
8. The composition of claim 6 , wherein R 20 is C 2 H 4 , and R 50 is C 3 H 6 .
9. The composition of claim 1 , wherein when the compound is in its salt form, the counterion is selected from the group consisting of a halide, a carboxylate, hydrogen sulfate, dihydrogen phosphate, nitrate, and a combination thereof.
10. The composition of claim 9 , wherein the counterion is an acetate, an acrylate, or a combination thereof.
11. The composition of claim 1 , wherein the composition further comprises a thermodynamic hydrate inhibitor, a kinetic hydrate inhibitor, an anti-agglomerant, or a combination thereof.
12. The composition of claim 1 , wherein the composition further comprises a polar solvent, a nonpolar solvent, or a mixture thereof.
13. A method of inhibiting formation of hydrate agglomerants in a fluid comprising water, a gas, and optionally a liquid hydrocarbon, comprising contacting the fluid with an effective amount of a hydrate inhibitor composition of claim 1 .
14. The method of claim 13 , wherein the effective amount is from about 0.1 to about 10 volume %, based on an amount of water.
15. A hydrate inhibitor composition comprising a hydrate-inhibiting effective amount of:
wherein R 11 is C 8 to C 20 alkyl, and R 12 and R 13 are independently C 1 to C 6 alkyl.
16. The composition of claim 15 wherein the compound of Formula 1 is: