A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effectiv...A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effective diffusion coefficient was proposed. It is found that the simulation results fit the experimental data well and the breakthrough time of the bed layer is predicted accurately. By modeling the alkylation process, the time-space distribution of butene and point activity profiles of catalysts can be obtained. Furthermore, the reasons for the deactivation of solid acid catalysts were investigated. It indicates that the main reason for the deactivation of catalysts is the site coverage near the inlet of the reactor, while it is ascribed to the steric effect in the region far away from the inlet.展开更多
An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole? as bonding agent. The original chitosan and the modified chitosan we...An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole? as bonding agent. The original chitosan and the modified chitosan were characterized by FT-IR and XRD analysis. FT-IR spectra revealed that the alkylation of chitosan selectively occurred at hydroxyl groups, with unprotected amino groups untouched. It was proposed that the particular properties of the ionic liquid solvent should be responsible for the selectively alkylation. The result from X-ray diffraction showed that the crystallinity of O-alkylation of chitosan decreases, most likely due to the decomposition of CS in the ionic liquid. The solubility test of O-alkylated chitosan in aqueous HAc solution (w/w: 0.1%) confirmed that the product could be easily dissolved in aqueous HAc solution because of its abundant free amino groups. It was suggested that the O-alkylated chitosan was suitable for the coming cell transfection test in vitro.展开更多
For the alkylation of benzene with long-chain olefins, using Hβzeolite catalyst as replacement of HF or AlCl3 has the advantages of no corrosion, less environmental pollution, and much more 2-phenyl isomer, which has...For the alkylation of benzene with long-chain olefins, using Hβzeolite catalyst as replacement of HF or AlCl3 has the advantages of no corrosion, less environmental pollution, and much more 2-phenyl isomer, which has the highest biodegradability and solubility, and better detergent properties among the related isomers. The characterization of the coke shows that the deactivation of catalyst is caused by the jam of bulkier molecules, such as naphthalene, indane and linear alkylbenzenes, which are too big to move quickly in the intracrystalline pores of catalyst. The deactivated catalyst can be regenerated by benzene washing at higher temperature. To make the processes of reaction and regeneration continuous, a novel moving bed reactor is developed. Comparing with the processes with fixed bed reactors, the processes in this work have the advantages of continuous operation, low temperature, low pressure, low mole ratio of benzene to olefins, and high weight hourly space velocity.展开更多
Dihydroxy toluene was synthesized from resorcinol in 4 steps:alkylation, methylacylation, Huang Ming Long reaction and dealkylation. In first two steps ethylene dichloride was used as the solvent. This made the two re...Dihydroxy toluene was synthesized from resorcinol in 4 steps:alkylation, methylacylation, Huang Ming Long reaction and dealkylation. In first two steps ethylene dichloride was used as the solvent. This made the two reactions easy and the yields high, and also decreased the amount of DMF used in second step. The third step was a modified Huang Ming Long reaction carried out at more mild condition. The total yield of the title compound was 62%.展开更多
文摘A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effective diffusion coefficient was proposed. It is found that the simulation results fit the experimental data well and the breakthrough time of the bed layer is predicted accurately. By modeling the alkylation process, the time-space distribution of butene and point activity profiles of catalysts can be obtained. Furthermore, the reasons for the deactivation of solid acid catalysts were investigated. It indicates that the main reason for the deactivation of catalysts is the site coverage near the inlet of the reactor, while it is ascribed to the steric effect in the region far away from the inlet.
文摘An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole? as bonding agent. The original chitosan and the modified chitosan were characterized by FT-IR and XRD analysis. FT-IR spectra revealed that the alkylation of chitosan selectively occurred at hydroxyl groups, with unprotected amino groups untouched. It was proposed that the particular properties of the ionic liquid solvent should be responsible for the selectively alkylation. The result from X-ray diffraction showed that the crystallinity of O-alkylation of chitosan decreases, most likely due to the decomposition of CS in the ionic liquid. The solubility test of O-alkylated chitosan in aqueous HAc solution (w/w: 0.1%) confirmed that the product could be easily dissolved in aqueous HAc solution because of its abundant free amino groups. It was suggested that the O-alkylated chitosan was suitable for the coming cell transfection test in vitro.
文摘For the alkylation of benzene with long-chain olefins, using Hβzeolite catalyst as replacement of HF or AlCl3 has the advantages of no corrosion, less environmental pollution, and much more 2-phenyl isomer, which has the highest biodegradability and solubility, and better detergent properties among the related isomers. The characterization of the coke shows that the deactivation of catalyst is caused by the jam of bulkier molecules, such as naphthalene, indane and linear alkylbenzenes, which are too big to move quickly in the intracrystalline pores of catalyst. The deactivated catalyst can be regenerated by benzene washing at higher temperature. To make the processes of reaction and regeneration continuous, a novel moving bed reactor is developed. Comparing with the processes with fixed bed reactors, the processes in this work have the advantages of continuous operation, low temperature, low pressure, low mole ratio of benzene to olefins, and high weight hourly space velocity.
文摘Dihydroxy toluene was synthesized from resorcinol in 4 steps:alkylation, methylacylation, Huang Ming Long reaction and dealkylation. In first two steps ethylene dichloride was used as the solvent. This made the two reactions easy and the yields high, and also decreased the amount of DMF used in second step. The third step was a modified Huang Ming Long reaction carried out at more mild condition. The total yield of the title compound was 62%.
