摘要:
A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is claimed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method comprise substantially water soluble polymers having N-vinyl amide or N-allyl amide units. Specific examples of such copolymers include, N-vinyl-N-methylacetamide (VIMA) copolymerized with acryloylpyrrolidine (APYD) or acryloylpiperidine (APID), and more preferably, VIMA copolymerized with N-substituted methacrylamides, such as N-isopropylmethacrylamide (iPMAM) and methacryloylpyrrolidine (MAPYD) to produce inhibitors for practicing the claimed method.
摘要:
Novel maleimide copolymers have at least two monomeric units, a maleimide unit and a vinyl unit having a pendant group, the pendant group having two to twenty-one carbon atoms, at least one nitrogen atom and at least one oxygen atom. The copolymer has an average molecular weight between about 1,000 and about 6,000,000. Preferred maleimide copolymers include acrylamide/maleimide copolymers, N-vinyl amide/maleimide copolymers, vinyl lactam/maleimide copolymers, alkenyl cyclic imino ether/maleimide copolymers, and acryloylamide/maleimide copolymers. The substantially water soluble maleimide copolymers are useful for inhibiting the formation of clathrate hydrates in a fluid having hydrate-forming constituents by reducing the rate of nucleation, growth, and/or agglomeration of gas hydrate crystals in a petroleum fluid stream, thereby inhibiting the formation of a hydrate blockage in the pipe conveying the petroleum fluid stream. The inhibitor can be used conveniently at low concentrations, for example in the range of from about 0.01% to about 5% by weight of the water present in the oil or gas stream, to effectively treat a petroleum fluid having a water phase.
摘要:
Novel maleimide copolymers have at least two monomeric units, a maleimide unit and a vinyl unit having a pendant group, the pendant group having two to twenty-one carbon atoms, at least one nitrogen atom and at least one oxygen atom. The copolymer has an average molecular weight between about 1,000 and about 6,000,000. Preferred maleimide copolymers include acrylamide/maleimide copolymers, N-vinyl amide/maleimide copolymers, vinyl lactam/maleimide copolymers, alkenyl cyclic imino ether/maleimide copolymers, and acryloylamide/maleimide copolymers. The substantially water soluble maleimide copolymers are useful for inhibiting the formation of clathrate hydrates in a fluid having hydrate-forming constituents by reducing the rate of nucleation, growth, and/or agglomeration of gas hydrate crystals in a petroleum fluid stream, thereby inhibiting the formation of a hydrate blockage in the pipe conveying the petroleum fluid stream. The inhibitor can be used conveniently at low concentrations, for example in the range of from about 0.01% to about 5% by weight of the water present in the oil or gas stream, to effectively treat a petroleum fluid having a water phase.
摘要:
In a process for producing a functionalized polyalkenamer, at least one monomer comprising a monocyclic olefin having at least one pendant alkyl group bonded thereto, wherein the pendant alkyl group has at least two carbon atoms and is substituted with a polar moiety spaced by at least one carbon atom from the monocyclic olefin, is contacted with a polymerization catalyst under conditions effective to effect ring opening polymerization of the monocyclic olefin and produce the functionalized polyalkenamer.
摘要:
In a process for producing a functionalized polyalkenamer, at least one monomer comprising a monocyclic olefin having at least one pendant alkyl group bonded thereto, wherein the pendant alkyl group has at least two carbon atoms and is substituted with a polar moiety spaced by at least one carbon atom from the monocyclic olefin, is contacted with a polymerization catalyst under conditions effective to effect ring opening polymerization of the monocyclic olefin and produce the functionalized polyalkenamer.
摘要:
In a process for producing a functionalized polyalkenamer, at least one monomer comprising a monocyclic olefin having at least one pendant alkyl group bonded thereto, wherein the pendant alkyl group has at least two carbon atoms and is substituted with a polar moiety spaced by at least one carbon atom from the monocyclic olefin, is contacted with a polymerization catalyst under conditions effective to effect ring opening polymerization of the monocyclic olefin and produce the functionalized polyalkenamer.
摘要:
Disclosed is a selected type of copolymer composition comprising copolymers having units derived from ethylene and dicyclopentadiene (DCPD) co-monomers. Such copolymer compositions: a) have a DCPD-derived comonomer unit content of from about 25 mole % to about 45 mole %; b) have a Weight Average Molecular Weight, Mw, of greater than about 170,000; c) comprise amorphous material and have glass transition temperatures, Tg, of from about 8° C. to about 129° C., which also fit the equation Tg (in ° C.)≧[(mole % DCPD×3.142)−4.67]; and d) comprise no significant amount of crystalline polyethylene homopolymer or crystallizable polyethylene segments within the ethylene-dicylopentadiene copolymers. Such copolymers can be readily derivatized by hydrogention and/or epoxidation to provide polymeric materials suitable for use as engineering thermoplastics.Also disclosed are processes for preparing and optionally further derivatizing ethylene/dicyclopentadiene copolymers having the characteristics hereinbefore described. Such processes comprise: a) contacting ethylene with a polymerization mixture comprising greater than about 4.0 molar dicyclopentadiene, in the presence of a selected activated cyclopentadienyl-fluorenyl metallocene catalyst bearing a substituent, preferably a methyl substituent, at the 3-position of the cyclopentadienyl ring, under specific polymerization conditions including relatively high ethylene pressures to thereby form the desired ethylene-dicyclopentadiene copolymers within the polymerization mixture. Such copolymers are then recovered and/or further hydrogenated or functionalized.
摘要:
Disclosed is a selected type of copolymer composition comprising copolymers having units derived from ethylene and dicyclopentadiene (DCPD) co-monomers. Such copolymer compositions: a) have a DCPD-derived comonomer unit content of from about 25 mole % to about 45 mole %; b) have a Weight Average Molecular Weight, Mw, of greater than about 170,000; c) comprise amorphous material and have glass transition temperatures, Tg, of from about 8° C. to about 129° C., which also fit the equation Tg (in ° C.)≧[(mole % DCPD×3.142)−4.67]; and d) comprise no significant amount of crystalline polyethylene homopolymer or crystallizable polyethylene segments within the ethylene-dicyclopentadiene copolymers. Such copolymers can be readily derivatized by hydrogenation and/or epoxidation to provide polymeric materials suitable for use as engineering thermoplastics. Also disclosed are processes for preparing and optionally further derivatizing ethylene/dicyclopentadiene copolymers having the characteristics hereinbefore described.
摘要:
In a process for producing a functionalized polyalkenamer, at least one monomer comprising a monocyclic olefin having at least one pendant alkyl group bonded thereto, wherein the pendant alkyl group has at least two carbon atoms and is substituted with a polar moiety spaced by at least one carbon atom from the monocyclic olefin, is contacted with a polymerization catalyst under conditions effective to effect ring opening polymerization of the monocyclic olefin and produce the functionalized polyalkenamer.