Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activi...Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activity is very low and obvious deactivation of catalyst is observed in a short run.This paper aims at slowing down catalyst deactivation and improving reaction activity of alkylation of methylnaphthalene with methanol by taking advantage of some special properties of supercritical fluids, such as higher solubility than gases and higher diffusivity than liquids. The results indicate that the reaction under supercritical condition will achieve high reaction activity and long catalyst life. When the reaction was carried out at 460 ℃ and 7.0 MPa which is above the critical temperature and pressure of the inert reaction solvent,1,3,5-trimethylbenzene, the reaction activity increased by 3 times and catalyst life was extended by 25 to 30 times than those under ambient pressure and at the same temperature.展开更多
The heat transfer coefficient is very low at bulk temperatures higher than the pseudo-critical point,because the supercritical pressure leads to a vapor-like fluid.In this paper,the heat transfer downstream an obstacl...The heat transfer coefficient is very low at bulk temperatures higher than the pseudo-critical point,because the supercritical pressure leads to a vapor-like fluid.In this paper,the heat transfer downstream an obstacle-bearing vertical tube is simulated by the CFD code of Fluent 6.1,using an adaptive grid in the supercritical condition.The reliable results are obtained by the RNG k-ε model using the enhanced wall treatment.The blockage ratio and local temperature of obstacle affect greatly the heat transfer enhancement,and the resultant influence region and decay trend are compared with the existing equations.展开更多
基金国家自然科学基金 (No 2 0 2 760 112 0 3 760 12 )黑龙江省科学院重点基金 (No 2 0 0 0 0 1 12)资助项目~~
文摘Alkylation of methylnaphthalene with methanol is one promising technology for producing 2,6-dimethylnaphthalene. When the alkylation is carried out under ambient pressure by using HZMS-5 catalysis, the reaction activity is very low and obvious deactivation of catalyst is observed in a short run.This paper aims at slowing down catalyst deactivation and improving reaction activity of alkylation of methylnaphthalene with methanol by taking advantage of some special properties of supercritical fluids, such as higher solubility than gases and higher diffusivity than liquids. The results indicate that the reaction under supercritical condition will achieve high reaction activity and long catalyst life. When the reaction was carried out at 460 ℃ and 7.0 MPa which is above the critical temperature and pressure of the inert reaction solvent,1,3,5-trimethylbenzene, the reaction activity increased by 3 times and catalyst life was extended by 25 to 30 times than those under ambient pressure and at the same temperature.
基金Supported by Xi'an Jiaotong Unversity(XJTU)Atomic Energy of Canada Limited(AECL)
文摘The heat transfer coefficient is very low at bulk temperatures higher than the pseudo-critical point,because the supercritical pressure leads to a vapor-like fluid.In this paper,the heat transfer downstream an obstacle-bearing vertical tube is simulated by the CFD code of Fluent 6.1,using an adaptive grid in the supercritical condition.The reliable results are obtained by the RNG k-ε model using the enhanced wall treatment.The blockage ratio and local temperature of obstacle affect greatly the heat transfer enhancement,and the resultant influence region and decay trend are compared with the existing equations.
