Patent EA-002135-B1 (EA)
Title: Method and compound for inhibiting the plugging of conduits by gas hydrates
Inventor: KLOMP ULFERT CORNELIS
IPC: C10L3/00
Filed: 1998-09-08
Abstract: 1. A method for inhibiting the plugging of a conduit, the conduit containing a mixture comprising an amount of hydrocarbons having from one to eight carbon atoms and an amount of water wherein the amounts of hydrocarbons and water could form hydrates at conduit temperatures and pressures, the method comprising the steps of: adding to the mixture an amount of a hydrate formation inhibitor component of formula (I) (R1)(R2)(R3)(R4)A<+>Y<->            (I) wherein two of R1 -R4 are independently normal or branched alkyls having 4 or 5 carbon atoms, two of R1 -R4 are independently representing organic moieties having at least 8 carbon atoms, A represents a nitrogen or phosphorus atom, Y represents an anion, and wherein at least one of R1 -R4 represents a --(CH2 -CHR5 --O)p --(CH2)q --(CHR6 -CH2)r --(CH2 -CHR7)s --(CHR8)t --O--C(O)-R9 moiety wherein R5 -R8 each independently represent a hydrogen atom or a C1 -C4 alkyl group and at least one of R6 -R8 is not a hydrogen atom; p represents 0 or an integer of up to 50; q, r, s, and t are 0, 1 or 2 and together at least 1 and not more than 4 and wherein when q represents 1 or 2 the sum of r, s, and t is at least 1 and, wherein when t and the sum of q, r, s and t represent 2, R8 does not represent a methyl group; and R9 represents an (cyclo)alkyl, alkenyl, aryl, arylalkyl, arylalkenyl, alkylaryl or alkenylaryl group having at least a carbon chain of 6 atoms, the amount of hydrate formation inhibitor component being effective to inhibit formation of hydrates in the mixture at conduit temperatures and pressures, and flowing the mixture containing the hydrate formation inhibitor component through the conduit. 2. The method according to claim 1, wherein A represents nitrogen and two of R1 -R4 independently contain between 8 and 20 carbon atoms. 3. The method according to claim 1 or 2, wherein two of R1 -R4 contain the same number of carbon atoms, each being at least 8. 4. The method according to claims 1 to 3, wherein R6, R7 and R8 each independently represent hydrogen or a methyl or ethyl group. 5. The method according to claim 4, wherein p is zero, the sum of q, r, s, and t is 2 and R9 repreents an alkyl or alkenyl group of between 9 and 18 carbon atoms. 6. The method according to claim 5, wherein q and t are 1 and R8 represents a methyl or ethyl group. 7. The method according to claims 1 to 6, wherein R9 represents the carbon chain of coconut fatty acid or tallow fatty acid. 8. The method according to claims 1 to 7, wherein the anion represents a hydroxide, a carboxylate, a halide, a sulphate or an organic sulphonate. 9. The method according to claims 1 to 8, wherein between 0.05 and 11% wt, based on the water content, of the hydrate formation inhibitor component is added to the water/hydrocarbon mixture. 10. The method according to claim 9, wherein the amount of hydrate formation inhibitor component added is between 0.1 and 5% wt, preferably 0.1 and 0.5, based on the water content. 11. The method according to claims 1 to 10, wherein a corrosion inhibitor is added to the hydrocarbon/water mixture. 12. The method according to claims 1 to 11, wherein a polymer of an ethylenically unsaturated N-heterocyclic carbonyl compound is added to the hydrocarbon/water mixture. 13. The method according to claims 1 to 12, wherein the step of flowing the mixture containing the hydrate formation inhibitor component through the conduit is effected after a shutdown which caused separation of hydrate crystals from the mixture. 14. The method according to claim 13, wherein the step of flowing the mixture is effected with a hydrocarbon/water mixture which has been subjected during shutdown to a decrease in temperature of more than 12 degree C, preferably at lest to 14 degree C. 15. Compounds of general formula (I) wherein at least one of R1 -R4 is a group --(CH2 -CHR5 --O)p --(CH2)q --(CHR6 -CH2)r --(CH2 -CHR7)s --(CHR8)t --O--C(O)-R9 moiety wherein two of R1 -R4 are independently normal or branched alkyls having 4 or 5 carbon atoms, two of R1 -R4 are independently representing organic moieties having at least 8 carbon atoms, A represents a nitrogen or phosphorus atom, Y represents an anion, and wherein at least one of R1 -R4 represents a --(CH2 -CHR5 --O)p --(CH2)q --(CHR6 -CH2)r --(CH2 -CHR7)s --(CHR8)t --O--C(O)-R9 moiety wherein R5 -R8 each independently represent a hydrogen atom or a C1 -C4 alkyl group and at least one of R6 -R8 is not a hydrogen atom; p represents 0 or an integer of up to 50; q, r, s, and t are 0, 1 or 2 and together at least 1 and not more than 4 and wherein when q represents 1 or 2 the sum of r, s, and t is at least 1 and, wherein when t and the sum of q, r, s and t represent 2, R8 does not represent a methyl group; and R9 represents an (cyclo)alkyl, alkenyl, aryl, arylalkyl, arylalkenyl, alkylaryl or alkenylaryl group having at least a carbon chain of 6 atoms, 16. Compounds of claim 15, wherein two of R1 -R4 have meanings as defined in claim 15. 17. Compounds of claims 15 or 16, wherein A is a nitrogen atom and two of R1 -R4 independently contain between 8 and 20 carbon atoms, preferably between 10 and 16 carbon atoms. 18. Compounds of claims 15 to 17, wherein two of R1 -R4 contain the same number of carbon atoms, each being at least 8. 19. Compounds of claims 15 to 18, wherein R6, R7 and R8 each independently represent a hydrogen atom or a methyl or ethyl group. 20. Compounds of claim 19, wherein p is zero, the sum of q, r, s and t is 2 and R9 represents an alkyl or alkenyl group of between 9 and 18 carbon atoms. 21. Compounds of claim 20, wherein q and t are 1 and R8 represents a methyl or ethyl group. 22. Compounds of claims 15 to 21, wherein R9 represents the carbon chain of coconut fatty acid or tallow fatty acid. 23. Compounds of claims 15 to 22, wherein the anion represents a hydroxide, a carboxylate, a halide, a sulphate or an organic sulphonate. 24. Di-ester of di-butyl -di-isopropanol ammonium bromide and of coconut fatty acid. 25. Di-ester of di-butyl -di-isobutanoll ammonium bromide and of coconut fatty acid. 26. A composiion containing one or more hydrate formation inhibitor components of formula (I), liquid hydrocarbon and, optionally, a corrosion inhibitor, wherein the components of formula (I) contain compounds, wherein: two of R1 -R4 are independently normal or branched alkyls having 4 or 5 carbon atoms, two of R1 -R4 are independently representing organic moieties having at least 8 carbon atoms, A represents a nitrogen or phosphorus atom, Y represents an anion, and wherein at least one of R1 -R4 represents a --(CH2 -CHR5 --O)p --(CH2)q --(CHR6 -CH2)r --(CH2 -CHR7)s --(CHR8)t --O--C(O)-R9 moiety wherein R5 -R8 each independently represent a hydrogen atom or a C1 -C4 alkyl group and at least one of R6 -R8 is not a hydrogen atom; p represents 0 or an integer of up to 50; q, r, s, and t are 0, 1 or 2 and together at least 1 and not more than 4 and wherein when q represents 1 or 2 the sum of r, s, and t is at least 1 and, wherein when t and the sum of q, r, s and t represent 2, R8 does not represent a methyl group; and R9 represents an (cyclo)alkyl, alkenyl, aryl, arylalkyl, arylalkenyl, alkylaryl or alkenylaryl group having at least a carbon chain of 6 atoms, 27. Compositions of claim 26, wherein two of R1 -R4 have meanings as defined in claim 26. 28. Compositions of claims 26 or 27, wherein A is a nitrogen atom and two of R1 -R4 independently contain between 8 and 20 carbon atoms, preferably between 10 and 16 carbon atoms. 29. Compositions of claims 26 to 28, wherein two of R1 -R4 contain the same number of carbon atoms, each being at least 8. 30. Compositions of claims 26 to 29, wherein R6, R7 and R8 each independently represent a hydrogen atom or a methyl or ethyl group. 31. Compositions of claim 30, wherein p is zero, the sum of q, r, s and t is 2 and R9 represents an alkyl or alkenyl group of between 9 and 18 carbon atoms. 32. Compositions of claim 26, wherein q and t are 1 and R8 represents a methyl or ethyl group. 33. Compositions of claims 26 to 32, wherein R9 represents the carbon chain of coconut fatty acid or tallow fatty acid. 34. Compositions of claims 26 to 33, wherein the anion represents a hydroxide, a carboxylate, a halide, a sulphate or an organic sulphonate. 35. Compositions of claims 26 to 34, wherein the hydrocarbon liquid is a mixture of paraffinic and naphthenic hydrocarbons and/or an aromatic solvent derived from kerosene. 36. Compositions of claims 26 to 35, wherein the compound according to formula (I) is the di-ester of di-butyl di-isopropanol ammonium bromide and coconut fatty acid. 37. Compositions of claims 26 to 36, wherein the compound according to formula (I) is the di-ester of di-butyl di-isobutanol ammonium bromide and coconut fatty acid.