Efficient conversion of lignin to fine chemicals and biofuel become more and more attractive in biorefinery. In this work, we used a series of silica-alumina catalysts （i.e., SiO2-Al2O3, HY, Hβ, and HZSM-5） to degr...Efficient conversion of lignin to fine chemicals and biofuel become more and more attractive in biorefinery. In this work, we used a series of silica-alumina catalysts （i.e., SiO2-Al2O3, HY, Hβ, and HZSM-5） to degrade lignin into arenes and phenols. The relationship between the catalyst structure and lignin depolymerization performance was investigated. The results showed that both acidity and pore size of the catalyst could influence the conversion of lignin. In the volatilizable product, phenols were identified as the main phenolic monomers via gas chromatography-mass spectrometer. SIO2-Al2O3 was the most efficient catalyst, giving 90.96% degree of conversion, 12.91% yield of phenols, and 2.41% yield of arenes in ethanol at 280℃ for 4 h. The Fourier transform infrared spectroscopy and ^1H nuclear magnetic resonance spectroscopy analysis demonstrated that deoxygenation and alkylation occurred in this process. The effect of solvents was also investigated and the results showed that ethanol was the most efficient solvent.展开更多
研究了几种磺酸功能化离子液体催化纤维素在生物丁醇中转化为乙酰丙酸丁酯的性能.系统考察了催化剂的酸强度,用量,反应温度,时间和溶剂对纤维素转化效率和产物分布规律的影响.实验结果表明酸度最强的磺酸功能化离子液体1-(4-磺酸丁基)-3...研究了几种磺酸功能化离子液体催化纤维素在生物丁醇中转化为乙酰丙酸丁酯的性能.系统考察了催化剂的酸强度,用量,反应温度,时间和溶剂对纤维素转化效率和产物分布规律的影响.实验结果表明酸度最强的磺酸功能化离子液体1-(4-磺酸丁基)-3-甲基咪唑硫酸氢盐([C4H8SO3Hmim]HSO4)能够有效地催化纤维素转化为乙酰丙酸丁酯,且在优化的反应条件下纤维素的转化率高达98.4%,乙酰丙酸丁酯的产率为31.1%,同时共生产物甲酸丁酯、水溶性产物和生物油的产率分别为33.4%、20.6%和23.8%.该催化体系具有一定的耐水性能,水的添加量为0.2 m L时并不会严重影响纤维素的转化率.此外,酸性离子液体催化剂还表现出了良好的重复使用性能,使用六次后仍然保持较高的活性.展开更多
The rules on regulating aromatic compounds production was investigated by aqueous cat- alytic reforming of sorbitol. It was found that aromatics, ketones, furans, organic acids were main compounds in organic phase. Th...The rules on regulating aromatic compounds production was investigated by aqueous cat- alytic reforming of sorbitol. It was found that aromatics, ketones, furans, organic acids were main compounds in organic phase. The obvious effect of metal content showed that the highest carbon selectivity of aromatics was 34.36% when 3wt% Ni content was loaded on HZSM-5 zeolite modified by MCM-41. However, it was decreased only to 4.82% when Ni content was improved to 20wt%. Meanwhile, different reaction parameters also displayed important impacts on carbon selectivity. It was improved with the increase of temperature, while it was decreased as liquid hourly space velocity and hydrogen pressure was increased. The results showed that appropriate higher temperature, longer contact time and lower hy- drogen pressure were in favor of aromatics information, which suggested a feasible process to solve energy crisis.展开更多
随着气体绝缘金属封闭开关设备(GIS)的广泛应用,经常会遇到母线较长的情况。尤其是户外安装的大电站,温差变化大,母线的热胀冷缩补偿尤其重要。文中以河南许昌长葛南变电站110 k V工程为例,对GIS母线进行热胀冷缩分析与计算,提出了一种...随着气体绝缘金属封闭开关设备(GIS)的广泛应用,经常会遇到母线较长的情况。尤其是户外安装的大电站,温差变化大,母线的热胀冷缩补偿尤其重要。文中以河南许昌长葛南变电站110 k V工程为例,对GIS母线进行热胀冷缩分析与计算,提出了一种采用柔性支架进行补偿的方法,采用有限元仿真方法对柔性支架的最大偏移量和强度进行计算。计算结果表明:采用柔性支架完全可以满足长直母线的热胀冷缩补偿要求,有效地保证了产品安全可靠运行。展开更多
基金supported by the National Natural Science Foundation of China (20876055, 21076085)Fundamental Research Funds for the Central Universities, SCUT, China~~
文摘Efficient conversion of lignin to fine chemicals and biofuel become more and more attractive in biorefinery. In this work, we used a series of silica-alumina catalysts （i.e., SiO2-Al2O3, HY, Hβ, and HZSM-5） to degrade lignin into arenes and phenols. The relationship between the catalyst structure and lignin depolymerization performance was investigated. The results showed that both acidity and pore size of the catalyst could influence the conversion of lignin. In the volatilizable product, phenols were identified as the main phenolic monomers via gas chromatography-mass spectrometer. SIO2-Al2O3 was the most efficient catalyst, giving 90.96% degree of conversion, 12.91% yield of phenols, and 2.41% yield of arenes in ethanol at 280℃ for 4 h. The Fourier transform infrared spectroscopy and ^1H nuclear magnetic resonance spectroscopy analysis demonstrated that deoxygenation and alkylation occurred in this process. The effect of solvents was also investigated and the results showed that ethanol was the most efficient solvent.
基金supported by the National Natural Science Foundation of China(21336002,21276094)Doctoral Fund of Ministry of Education of China(20130172110043)~~
文摘研究了几种磺酸功能化离子液体催化纤维素在生物丁醇中转化为乙酰丙酸丁酯的性能.系统考察了催化剂的酸强度,用量,反应温度,时间和溶剂对纤维素转化效率和产物分布规律的影响.实验结果表明酸度最强的磺酸功能化离子液体1-(4-磺酸丁基)-3-甲基咪唑硫酸氢盐([C4H8SO3Hmim]HSO4)能够有效地催化纤维素转化为乙酰丙酸丁酯,且在优化的反应条件下纤维素的转化率高达98.4%,乙酰丙酸丁酯的产率为31.1%,同时共生产物甲酸丁酯、水溶性产物和生物油的产率分别为33.4%、20.6%和23.8%.该催化体系具有一定的耐水性能,水的添加量为0.2 m L时并不会严重影响纤维素的转化率.此外,酸性离子液体催化剂还表现出了良好的重复使用性能,使用六次后仍然保持较高的活性.
文摘The rules on regulating aromatic compounds production was investigated by aqueous cat- alytic reforming of sorbitol. It was found that aromatics, ketones, furans, organic acids were main compounds in organic phase. The obvious effect of metal content showed that the highest carbon selectivity of aromatics was 34.36% when 3wt% Ni content was loaded on HZSM-5 zeolite modified by MCM-41. However, it was decreased only to 4.82% when Ni content was improved to 20wt%. Meanwhile, different reaction parameters also displayed important impacts on carbon selectivity. It was improved with the increase of temperature, while it was decreased as liquid hourly space velocity and hydrogen pressure was increased. The results showed that appropriate higher temperature, longer contact time and lower hy- drogen pressure were in favor of aromatics information, which suggested a feasible process to solve energy crisis.
文摘随着气体绝缘金属封闭开关设备(GIS)的广泛应用,经常会遇到母线较长的情况。尤其是户外安装的大电站,温差变化大,母线的热胀冷缩补偿尤其重要。文中以河南许昌长葛南变电站110 k V工程为例,对GIS母线进行热胀冷缩分析与计算,提出了一种采用柔性支架进行补偿的方法,采用有限元仿真方法对柔性支架的最大偏移量和强度进行计算。计算结果表明:采用柔性支架完全可以满足长直母线的热胀冷缩补偿要求,有效地保证了产品安全可靠运行。
