Hydrotreating of vacuum residue by ebullated-bed shows tremendous significance due to more stringent environmental regulations and growing demand for lighter fuels. However, enhancing the catalyst stability still rema...Hydrotreating of vacuum residue by ebullated-bed shows tremendous significance due to more stringent environmental regulations and growing demand for lighter fuels. However, enhancing the catalyst stability still remains as a challenging task. Herein, two Ni–Mo/Al_(2)O_(3) catalysts with distinct morphologies(i.e., spherical and cylindrical) were first designed, and the morphology effect on deactivation was systematically elucidated employing multi-characterizations, such as HRTEM with EDX mapping, electron microprobe analysis, FT-IR, TGA and Raman. It is found that spherical catalyst exhibits superior hydrotreating stability over 1600 h. The carbonaceous deposits on spherical catalyst with less graphite structure are lighter, and the coke weight is also smaller. In addition, the metal deposits uniformly distribute in the spherical catalyst, which is better than the concentrated distribution near the pore mouth for the cylindrical catalyst. Furthermore, the intrinsic reason for the differences was analyzed by the bed expansion experiment. Higher bed expansion rate together with the better mass transfer ability leads to the enhanced performance. This work sheds new light on the design of more efficient industrial hydrotreating catalyst based on morphology effect.展开更多
Ammonium chloride corrosion in the reactor effluent system remains to be a barrier for the safe operation of the ebullated-bed hydrogenation unit as impurity content is higher compared with that of the ordinary hydrog...Ammonium chloride corrosion in the reactor effluent system remains to be a barrier for the safe operation of the ebullated-bed hydrogenation unit as impurity content is higher compared with that of the ordinary hydrogenation units.In this research,a Sinopec envisaged case study was conducted on feed oil containing 2.92μg/g of Cl and 0.38%of N,because the impurity content of feed oil was representative in residue oil.The deposition patterns in heat exchangers were investigated by changing process variables,and then water wash strategy was optimized in view of the relative humidity to obtain a minimum water flowrate,and finally the process optimization suggestions concerning the operation of heat exchangers were proposed.Results show that with the measured content of nitrogen and chlorine in the feed,the NH4Cl deposition temperature of hot high-pressure vapor and hot low-pressure vapor was 223.4℃ and 173.7℃,respectively,and the minimum water wash flowrate for heat exchangers of hot high-pressure vapor with mixed hydrogen and hot low-pressure vapor with cold low-pressure oil was 38.0 t/h and 5.4 t/h,respectively.Water wash should be carried out intermittently upstream of the heat exchanger tube passes.In consideration of energy consumption,it is recommended to reduce the tube pass outlet temperature of the above heat exchangers to 240℃ and 190℃,respectively.展开更多
基金supported by Natural Science Foundation of China(21978325)the National Key Technologies Research and Development Program of China(2017YFB0306503)+5 种基金Fundamental Research Funds for the Central Universities(18CX02130A,18CX02014A)Open Project of State Key Laboratory of Chemical Engineering(SKL-Ch E-18C04)Doctoral Start-up Foundation of Liaoning Province(2019-BS054)Program for Liaoning Innovative Talents in University(XLYC1807245)China Postdoctoral Science Foundation(2019M661409)High-level Talent Innovation and Business Project of Dalian(2017RQ085)。
文摘Hydrotreating of vacuum residue by ebullated-bed shows tremendous significance due to more stringent environmental regulations and growing demand for lighter fuels. However, enhancing the catalyst stability still remains as a challenging task. Herein, two Ni–Mo/Al_(2)O_(3) catalysts with distinct morphologies(i.e., spherical and cylindrical) were first designed, and the morphology effect on deactivation was systematically elucidated employing multi-characterizations, such as HRTEM with EDX mapping, electron microprobe analysis, FT-IR, TGA and Raman. It is found that spherical catalyst exhibits superior hydrotreating stability over 1600 h. The carbonaceous deposits on spherical catalyst with less graphite structure are lighter, and the coke weight is also smaller. In addition, the metal deposits uniformly distribute in the spherical catalyst, which is better than the concentrated distribution near the pore mouth for the cylindrical catalyst. Furthermore, the intrinsic reason for the differences was analyzed by the bed expansion experiment. Higher bed expansion rate together with the better mass transfer ability leads to the enhanced performance. This work sheds new light on the design of more efficient industrial hydrotreating catalyst based on morphology effect.
基金This research is supported by the Scientific and Technological Development Project of Sinopec:‘Comprehensive Processing and Related Technology Research of Heavy Oil Ebullated-Bed Hydrogenation’,Contract No.118013-4.
文摘Ammonium chloride corrosion in the reactor effluent system remains to be a barrier for the safe operation of the ebullated-bed hydrogenation unit as impurity content is higher compared with that of the ordinary hydrogenation units.In this research,a Sinopec envisaged case study was conducted on feed oil containing 2.92μg/g of Cl and 0.38%of N,because the impurity content of feed oil was representative in residue oil.The deposition patterns in heat exchangers were investigated by changing process variables,and then water wash strategy was optimized in view of the relative humidity to obtain a minimum water flowrate,and finally the process optimization suggestions concerning the operation of heat exchangers were proposed.Results show that with the measured content of nitrogen and chlorine in the feed,the NH4Cl deposition temperature of hot high-pressure vapor and hot low-pressure vapor was 223.4℃ and 173.7℃,respectively,and the minimum water wash flowrate for heat exchangers of hot high-pressure vapor with mixed hydrogen and hot low-pressure vapor with cold low-pressure oil was 38.0 t/h and 5.4 t/h,respectively.Water wash should be carried out intermittently upstream of the heat exchanger tube passes.In consideration of energy consumption,it is recommended to reduce the tube pass outlet temperature of the above heat exchangers to 240℃ and 190℃,respectively.
