在300 m L连续加氢实验装置上,以神华鄂尔多斯直接液化工厂生产的加氢稳定油为原料,以加氢精制剂RNC-2为催化剂,考察了不同反应温度和体积空速对加氢产物性质及加氢精制反应过程的影响。结果表明:升高反应温度或降低体积空速,芳烃加氢...在300 m L连续加氢实验装置上,以神华鄂尔多斯直接液化工厂生产的加氢稳定油为原料,以加氢精制剂RNC-2为催化剂,考察了不同反应温度和体积空速对加氢产物性质及加氢精制反应过程的影响。结果表明:升高反应温度或降低体积空速,芳烃加氢饱和反应过程中的氢耗增大,产品油的密度、运动黏度及馏程降低;从不同反应条件加氢产品油中芳烃组成可以看出,芳烃加氢饱和反应过程中,总芳烃饱和率随反应温度的升高而升高、随体积空速的增大而降低,同时产物中多环芳烃饱和率>双环芳烃饱和率>单环芳烃饱和率,当反应温度为395℃、体积空速为0.7 h;时,总芳烃饱和率达到70.17%,同时加氢产品油中总环烷烃含量高达70.5%;煤直接液化加氢稳定油经过加氢精制反应后,其多环芳烃的质量分数均低于1%,硫和氮元素含量均低于10 mg/L,可用于制备高附加值环境友好型环烷基基础油。展开更多
CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applica...CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the CO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form CO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that CO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that CO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the CO molecule.展开更多
文摘在300 m L连续加氢实验装置上,以神华鄂尔多斯直接液化工厂生产的加氢稳定油为原料,以加氢精制剂RNC-2为催化剂,考察了不同反应温度和体积空速对加氢产物性质及加氢精制反应过程的影响。结果表明:升高反应温度或降低体积空速,芳烃加氢饱和反应过程中的氢耗增大,产品油的密度、运动黏度及馏程降低;从不同反应条件加氢产品油中芳烃组成可以看出,芳烃加氢饱和反应过程中,总芳烃饱和率随反应温度的升高而升高、随体积空速的增大而降低,同时产物中多环芳烃饱和率>双环芳烃饱和率>单环芳烃饱和率,当反应温度为395℃、体积空速为0.7 h;时,总芳烃饱和率达到70.17%,同时加氢产品油中总环烷烃含量高达70.5%;煤直接液化加氢稳定油经过加氢精制反应后,其多环芳烃的质量分数均低于1%,硫和氮元素含量均低于10 mg/L,可用于制备高附加值环境友好型环烷基基础油。
基金Supported by the National Natural Science Foundation of China for Youth (Grant No. 20703040)
文摘CO poisoning to platinum catalysts has long been recognized as one of the major technical obstacles in heterogeneous catalysis and its successful removal represents a significant challenge to a wide variety of applications. Using density functional theory (DFT), we performed systematic theoretical calcula-tions to explore the CO removal mechanisms, in the presence of hydrogen, via oxidation by oxygen to form CO2 or reduction by hydrogen to form formaldehyde using a subnano Pt cluster as a model for catalyst nanoparticles. We show that CO oxidation is both thermochemically and kinetically difficult at low H coverage but becomes very exothermic with a moderate activation barrier at high H coverage, suggesting that the oxidation can be carried out readily at elevated temperatures. Doping the Pt cluster with Ru can significantly improve the oxidation thermochemical energy and moderately reduce the activation barrier. The results are consistent with experimental observations. We found that CO reduction by hydrogen to form formaldehyde is moderately endothermic. However, the reaction is predicted to be kinetically difficult due to the relatively high activation barriers associated with the sequential H attacks to the CO molecule.
