In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of cok...In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of coke precursor deposited on the surface of solid acid alkylation catalyst are clearly recognized and identified by means of various characterization approaches, including IR, NMR, GC MS and GC. According to the characterization results, the coke precursors are mainly made up of long chain saturated hydrocarbons and small amount of polynucleo aromatics. The coke precursors deposit on the catalysts do not block the pores of the catalysts, but deposited on the acid centres of catalyst. It causes that the acid strength of active centres of the catalyst descends, and selectivity for alkylation becomes worse. It is found that the species of coke precursor consist of C 13 ～C 21 paraffin. The results obtained in the project are different entirely from that other researchers gained before. It will be of benefit to investigate and find out new regeneration methods of solid acid alkylation catalyst.展开更多
Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activi...Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activity is very low and obvious deactivation of catalyst is observed in a short run.This paper aims at slowing down catalyst deactivation and improving reaction activity of alkylation of methylnaphthalene with methanol by taking advantage of some special properties of supercritical fluids, such as higher solubility than gases and higher diffusivity than liquids. The results indicate that the reaction under supercritical condition will achieve high reaction activity and long catalyst life. When the reaction was carried out at 460 ℃ and 7.0 MPa which is above the critical temperature and pressure of the inert reaction solvent,1,3,5-trimethylbenzene, the reaction activity increased by 3 times and catalyst life was extended by 25 to 30 times than those under ambient pressure and at the same temperature.展开更多
Low-temperature oxidation(LTO)is the main reaction that affects fuel formation in the in-situ combustion process,which has important significance for the subsequent combustion propulsion and the successful extraction ...Low-temperature oxidation(LTO)is the main reaction that affects fuel formation in the in-situ combustion process,which has important significance for the subsequent combustion propulsion and the successful extraction of crude oil.In this study,heavy oil was subjected to LTO reactions at different temperatures.Three types of reaction products with varying oxidation depths were characterized in terms of the number of oxygen atoms and the polarity of the molecule to reveal the low-temperature oxidation process of the heavy oil.Ketone compounds and acid polyoxides in the oil phase and deep oxidation products with a higher number of oxygen atoms in the coke were identified with increasing oxidation depth.The experimental results showed that the oxidation reaction of the heavy oil changed from kinetic-controlled to diffusion-controlled in the open oxidation system of the heavy oil as the oxidation depth increased.The oxidation reaction of the oil phase reached a maximum and stable value in oxygen content.The molecular compositions of the ketone compound and acid polyoxide did not change significantly with further increase in reaction temperature.The molecular compositions of the deep oxidation products with a higher number of oxygen atoms in the coke phase changed significantly.The coke precursor molecules with a lower oxygen content and condensation degree participated in the coke formation,and the oxidation reaction pathway and the complexity of the oxidation product component also increased.展开更多
文摘In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of coke precursor deposited on the surface of solid acid alkylation catalyst are clearly recognized and identified by means of various characterization approaches, including IR, NMR, GC MS and GC. According to the characterization results, the coke precursors are mainly made up of long chain saturated hydrocarbons and small amount of polynucleo aromatics. The coke precursors deposit on the catalysts do not block the pores of the catalysts, but deposited on the acid centres of catalyst. It causes that the acid strength of active centres of the catalyst descends, and selectivity for alkylation becomes worse. It is found that the species of coke precursor consist of C 13 ～C 21 paraffin. The results obtained in the project are different entirely from that other researchers gained before. It will be of benefit to investigate and find out new regeneration methods of solid acid alkylation catalyst.
基金国家自然科学基金 (No 2 0 2 760 112 0 3 760 12 )黑龙江省科学院重点基金 (No 2 0 0 0 0 1 12)资助项目~~
文摘Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activity is very low and obvious deactivation of catalyst is observed in a short run.This paper aims at slowing down catalyst deactivation and improving reaction activity of alkylation of methylnaphthalene with methanol by taking advantage of some special properties of supercritical fluids, such as higher solubility than gases and higher diffusivity than liquids. The results indicate that the reaction under supercritical condition will achieve high reaction activity and long catalyst life. When the reaction was carried out at 460 ℃ and 7.0 MPa which is above the critical temperature and pressure of the inert reaction solvent,1,3,5-trimethylbenzene, the reaction activity increased by 3 times and catalyst life was extended by 25 to 30 times than those under ambient pressure and at the same temperature.
基金supported by the National Key R&D Program of China(2018YFA0702400)the PetroChina Exploration&Production Company(KS2020-01-05).
文摘Low-temperature oxidation(LTO)is the main reaction that affects fuel formation in the in-situ combustion process,which has important significance for the subsequent combustion propulsion and the successful extraction of crude oil.In this study,heavy oil was subjected to LTO reactions at different temperatures.Three types of reaction products with varying oxidation depths were characterized in terms of the number of oxygen atoms and the polarity of the molecule to reveal the low-temperature oxidation process of the heavy oil.Ketone compounds and acid polyoxides in the oil phase and deep oxidation products with a higher number of oxygen atoms in the coke were identified with increasing oxidation depth.The experimental results showed that the oxidation reaction of the heavy oil changed from kinetic-controlled to diffusion-controlled in the open oxidation system of the heavy oil as the oxidation depth increased.The oxidation reaction of the oil phase reached a maximum and stable value in oxygen content.The molecular compositions of the ketone compound and acid polyoxide did not change significantly with further increase in reaction temperature.The molecular compositions of the deep oxidation products with a higher number of oxygen atoms in the coke phase changed significantly.The coke precursor molecules with a lower oxygen content and condensation degree participated in the coke formation,and the oxidation reaction pathway and the complexity of the oxidation product component also increased.
