The oligomerization of light olefins is considered a green production technology.Currently,the application of mordenite in isoamylene oligomerization faces two main challenges:low dimerization selectivity and poor sta...The oligomerization of light olefins is considered a green production technology.Currently,the application of mordenite in isoamylene oligomerization faces two main challenges:low dimerization selectivity and poor stability.In this work,a series of different SiO_(2)/Al_(2)O_(3) ratio mordenite are synthesized by utilizing hexamethyleneimine(HMI)as the organic structure directing agent,and it turns out that the rod-like zeolite with the ratio of SiO_(2)/Al_(2)O_(3)=14 exhibits the higher dimerization selectivity.The incorporation of TPOAC optimizes the pore structure and acid site distribution of the rod-like zeolite,which enables the samples to not only exhibit a conversion rate of isoamylene over 88.30% within 12 h,while maintaining good dimerization selectivity.These findings provide a promising approach for improving the efficiency and sustainability of olefin oligomerization processes.展开更多
Methoxyl methyl ether isoamylene quercetin （MIAQ） is one of the newly synthesized quercetin derivatives. The present study investigated the effect of MIAQ on rat aorta endothelial cells （RAECs） injured by hydrogen...Methoxyl methyl ether isoamylene quercetin （MIAQ） is one of the newly synthesized quercetin derivatives. The present study investigated the effect of MIAQ on rat aorta endothelial cells （RAECs） injured by hydrogen peroxide （H2O2）, as well as the potential mechanisms. We observed that MIAQ at 2.5-10μmol/L significantly enhanced the viability of injured RAECs, and the effect was more potent than quercetin and ct-tocopherol. However, M1AQ at the same concentration failed to show anti-oxidant activity in a cell-free system. In H2O2-injured endothelial cells treated with MIAQ （5-10μmol/L）, the level of nitric oxide （NO） and malondialdehyde was decreased, and the activities of superoxide dismutase and glutathione peroxidase was enhanced. In addition, RAECs treated with MIAQ （2.5-10 μmol/L） exhibited significant inhibiting apoptosis. In conclusion, MIAQ had protective effect on RAECs, possibly through increasing NO production and antioxidases activities, as well as inhibiting apoptosis. These findings suggest that MIAQ is possibly beneficial in the prevention of atherosclerosis and other diseases related to endothelial injury.展开更多
The present work contributed to a new developed production method for enhancing the quality of isoamylene （IA） by adding a small amount of tertiary amyl alcohol （TAA） to the catalyst of strong acid cation exchange...The present work contributed to a new developed production method for enhancing the quality of isoamylene （IA） by adding a small amount of tertiary amyl alcohol （TAA） to the catalyst of strong acid cation exchange resin. TAA improved the selectivity of 2-methyl-2-butene （2M2B） at a high conversion level for the isomerization of IA. Compared with the other results from the current IA units, the conversion of 2-methyl- 1-butene （2M1B）, the mass ratio of 2M2B to 2M1B and the selectivity of 2M2B were increased from 0.5474, 7.32 and 0.6864 to 0.72, 12 and 0.95, respectively, while the dimers content in the products decreased from 4.38% to below 1.0%. Optimized conditions for IA isomerization consisted of temperature between 28 and 33℃ and system pressure of 0.5 MPa, weight hourly space velocity of 8.0 h-1 with TAA mass fraction of 0.7%-0.9% in raw material. The results in lab supported bases for the developed process in industrial application which was later proved to be successful. In addition, a possible mechanism of the isomerization process was speculated to propose a key step of water formation in the TAA-added isomerization process and a verified experiment was conducted to support this speculation.展开更多
Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established...Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established to increase isoamylene conversion. Facing the challenge of improving product purity at the same time, an equilibrium stage model based design methodology is proposed and illustrated step-by-step for converting the Fischer-Tropsch C_5 olefins to tert-amyl methyl ether(TAME) process by using Aspen Plus. Under the guide of the proposed methodology, the design leads to a TAME product purity of higher than 95% and an isoamylene conversion of higher than 90%. The etherification kinetics over Amberlyst 35 is also studied within a temperature range of 60 ℃ to 75 ℃ to shed more light on the feasibility of process development. The methodology provides an effective reactive distillation column design to achieve the target reactant conversion and product purity simultaneously.展开更多
基金supported by the National Natural Science Foundation of China(21776505)。
文摘The oligomerization of light olefins is considered a green production technology.Currently,the application of mordenite in isoamylene oligomerization faces two main challenges:low dimerization selectivity and poor stability.In this work,a series of different SiO_(2)/Al_(2)O_(3) ratio mordenite are synthesized by utilizing hexamethyleneimine(HMI)as the organic structure directing agent,and it turns out that the rod-like zeolite with the ratio of SiO_(2)/Al_(2)O_(3)=14 exhibits the higher dimerization selectivity.The incorporation of TPOAC optimizes the pore structure and acid site distribution of the rod-like zeolite,which enables the samples to not only exhibit a conversion rate of isoamylene over 88.30% within 12 h,while maintaining good dimerization selectivity.These findings provide a promising approach for improving the efficiency and sustainability of olefin oligomerization processes.
基金National Natural Science Foundation of China (Grant No. 61071002)
文摘Methoxyl methyl ether isoamylene quercetin （MIAQ） is one of the newly synthesized quercetin derivatives. The present study investigated the effect of MIAQ on rat aorta endothelial cells （RAECs） injured by hydrogen peroxide （H2O2）, as well as the potential mechanisms. We observed that MIAQ at 2.5-10μmol/L significantly enhanced the viability of injured RAECs, and the effect was more potent than quercetin and ct-tocopherol. However, M1AQ at the same concentration failed to show anti-oxidant activity in a cell-free system. In H2O2-injured endothelial cells treated with MIAQ （5-10μmol/L）, the level of nitric oxide （NO） and malondialdehyde was decreased, and the activities of superoxide dismutase and glutathione peroxidase was enhanced. In addition, RAECs treated with MIAQ （2.5-10 μmol/L） exhibited significant inhibiting apoptosis. In conclusion, MIAQ had protective effect on RAECs, possibly through increasing NO production and antioxidases activities, as well as inhibiting apoptosis. These findings suggest that MIAQ is possibly beneficial in the prevention of atherosclerosis and other diseases related to endothelial injury.
文摘The present work contributed to a new developed production method for enhancing the quality of isoamylene （IA） by adding a small amount of tertiary amyl alcohol （TAA） to the catalyst of strong acid cation exchange resin. TAA improved the selectivity of 2-methyl-2-butene （2M2B） at a high conversion level for the isomerization of IA. Compared with the other results from the current IA units, the conversion of 2-methyl- 1-butene （2M1B）, the mass ratio of 2M2B to 2M1B and the selectivity of 2M2B were increased from 0.5474, 7.32 and 0.6864 to 0.72, 12 and 0.95, respectively, while the dimers content in the products decreased from 4.38% to below 1.0%. Optimized conditions for IA isomerization consisted of temperature between 28 and 33℃ and system pressure of 0.5 MPa, weight hourly space velocity of 8.0 h-1 with TAA mass fraction of 0.7%-0.9% in raw material. The results in lab supported bases for the developed process in industrial application which was later proved to be successful. In addition, a possible mechanism of the isomerization process was speculated to propose a key step of water formation in the TAA-added isomerization process and a verified experiment was conducted to support this speculation.
基金financial support from the National High Technology Research and Development Program 863(2011AA05A204)National Natural Science Foundation of China(U1361202)
文摘Isoamylene from the Fischer-Tropsch syncrude can be transformed to valuable fuel oxygenate additives through an equilibrium limited etherification reaction with methanol. A reactive distillation process is established to increase isoamylene conversion. Facing the challenge of improving product purity at the same time, an equilibrium stage model based design methodology is proposed and illustrated step-by-step for converting the Fischer-Tropsch C_5 olefins to tert-amyl methyl ether(TAME) process by using Aspen Plus. Under the guide of the proposed methodology, the design leads to a TAME product purity of higher than 95% and an isoamylene conversion of higher than 90%. The etherification kinetics over Amberlyst 35 is also studied within a temperature range of 60 ℃ to 75 ℃ to shed more light on the feasibility of process development. The methodology provides an effective reactive distillation column design to achieve the target reactant conversion and product purity simultaneously.
