The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of ...The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.展开更多
The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects...The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects of the type of aluminum co catalyst and its relative amount, the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined. The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum. It was likely to strongly modify the reactivity in the catalytic system when using phosphine ligand as additives, especially at the reaction temperature below 0 ℃. The catalytic system based on Ni( η 5 Ind) 2 complex displayed an extremely high productivity (TOF up to 169000 h -1 ) and a good regioselectivity to 2,3 dimethylbutenes (2,3 DMB) in dimers (66 4%) under proper reaction parameters.展开更多
The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ) complexes containing N-P bidentate ligands was studied in combination with organoaluminum co-catalysts. The effects of the type of a...The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ) complexes containing N-P bidentate ligands was studied in combination with organoaluminum co-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the nature of precursors in terms of ligand backbone and metal center were investigated. The results indicated that precursor I (N,N-dimethyl-2-(diphenylphosphino)aniline nickel (Ⅱ) dichloride) exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3Al2Cl3, whereas low productivity by its cobalt analogues was observed under identical reaction conditions.展开更多
基金supported by the National Natural Science Foundation of China under agreement number 22378026the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180508).
文摘The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.
文摘The catalytic performance of Ni( η 5 Ind) 2 complex in the dimerization of propylene was studied in combination with an organoaluminum co catalyst, eventually in the presence of a phosphine ligand. The effects of the type of aluminum co catalyst and its relative amount, the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined. The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum. It was likely to strongly modify the reactivity in the catalytic system when using phosphine ligand as additives, especially at the reaction temperature below 0 ℃. The catalytic system based on Ni( η 5 Ind) 2 complex displayed an extremely high productivity (TOF up to 169000 h -1 ) and a good regioselectivity to 2,3 dimethylbutenes (2,3 DMB) in dimers (66 4%) under proper reaction parameters.
文摘The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ) complexes containing N-P bidentate ligands was studied in combination with organoaluminum co-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the nature of precursors in terms of ligand backbone and metal center were investigated. The results indicated that precursor I (N,N-dimethyl-2-(diphenylphosphino)aniline nickel (Ⅱ) dichloride) exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3Al2Cl3, whereas low productivity by its cobalt analogues was observed under identical reaction conditions.
