Among the reactions catalyzed by zeolites there are some that exhibit high selectivity due to the spatial confinement effect of the zeolite framework.Tailoring the acidity,particularly the distribution and location of...Among the reactions catalyzed by zeolites there are some that exhibit high selectivity due to the spatial confinement effect of the zeolite framework.Tailoring the acidity,particularly the distribution and location of the Bronsted acid sites in the zeolite is effective for making it a better catalyst for these reactions.We prepared a series of H-mordenite（H-MOR） samples by varying the composition of the sol-gel,using different structure directing agents and post-treatment.NH3-TPD and IR characterization of adsorbed pyridine were employed to determine the amount of Bronsted acid sites in the 8-membered ring and 12-membered ring channels.It was shown that controlled synthesis was a promising approach to improve the concentration of Bronsted acid sites in MOR,even with a low Al content.Using an appropriate composition of Si and Al in the sol-gel favored a higher proportion of Bronsted acid sites in the 8-membered ring channels.HMI as a structure-direct agent gave an obvious enrichment of Bronsted acid sites in the 8-membered ring.Carbonylation of dimethyl ether was used as a probe reaction to examine the modification of the acid properties,especially the Bronsted acid sites in the 8-membered ring channels.There was a linear relationship between methyl acetate formation and the number of Bronsted acid sites in the 8-membered ring channels,demonstrating the successful modification of acid properties.Our results provide information for the rational design and modification of zeolites with spatial constraints.展开更多
Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-pu...Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.展开更多
介绍了采用脱酸剂 S 对直馏柴油进行脱酸精制方法,结果表明,当原料酸度为20.00 mgKOH/100 mL 时,S 剂的加入量为400 μg/g 即可,S 剂的加入量应随原料油酸度而变化;精制脱酸油的酸度应以尽量接近0为宜。对采用脱酸剂 S 精制柴油的效果...介绍了采用脱酸剂 S 对直馏柴油进行脱酸精制方法,结果表明,当原料酸度为20.00 mgKOH/100 mL 时,S 剂的加入量为400 μg/g 即可,S 剂的加入量应随原料油酸度而变化;精制脱酸油的酸度应以尽量接近0为宜。对采用脱酸剂 S 精制柴油的效果进行评价,结果表明,对成品柴油质量无不良影响,在柴油罐底水中加入3%的抗乳化剂 A 和0.2%抗酸度回升剂 E 可解决脱酸油乳化及遇水酸度回升问题。直馏柴油无碱脱酸成本简要概算为2.922元/t 油。展开更多
基金supported by the National Natural Science Foundation of China(21325626,21406120)the Postdoctoral Science Foundation of China(2014M560181,2015T80214)~~
文摘Among the reactions catalyzed by zeolites there are some that exhibit high selectivity due to the spatial confinement effect of the zeolite framework.Tailoring the acidity,particularly the distribution and location of the Bronsted acid sites in the zeolite is effective for making it a better catalyst for these reactions.We prepared a series of H-mordenite（H-MOR） samples by varying the composition of the sol-gel,using different structure directing agents and post-treatment.NH3-TPD and IR characterization of adsorbed pyridine were employed to determine the amount of Bronsted acid sites in the 8-membered ring and 12-membered ring channels.It was shown that controlled synthesis was a promising approach to improve the concentration of Bronsted acid sites in MOR,even with a low Al content.Using an appropriate composition of Si and Al in the sol-gel favored a higher proportion of Bronsted acid sites in the 8-membered ring channels.HMI as a structure-direct agent gave an obvious enrichment of Bronsted acid sites in the 8-membered ring.Carbonylation of dimethyl ether was used as a probe reaction to examine the modification of the acid properties,especially the Bronsted acid sites in the 8-membered ring channels.There was a linear relationship between methyl acetate formation and the number of Bronsted acid sites in the 8-membered ring channels,demonstrating the successful modification of acid properties.Our results provide information for the rational design and modification of zeolites with spatial constraints.
基金the National Natural Science Foundation of China(Grant No.51974054)Scientific and Technological Research Program of Chongqing Municipal Education Commission(No.KJQN202201537)+2 种基金Research Foundation of Chongqing University of Science and Technology(No.ckrc2020017)Natural Science Foundation Project of Chongqing(No.cstc2021jcyj-msxmX0911)Chongqing Science and Technology Commission(No.sl202100000144).
文摘Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.
文摘介绍了采用脱酸剂 S 对直馏柴油进行脱酸精制方法,结果表明,当原料酸度为20.00 mgKOH/100 mL 时,S 剂的加入量为400 μg/g 即可,S 剂的加入量应随原料油酸度而变化;精制脱酸油的酸度应以尽量接近0为宜。对采用脱酸剂 S 精制柴油的效果进行评价,结果表明,对成品柴油质量无不良影响,在柴油罐底水中加入3%的抗乳化剂 A 和0.2%抗酸度回升剂 E 可解决脱酸油乳化及遇水酸度回升问题。直馏柴油无碱脱酸成本简要概算为2.922元/t 油。
