In situ catalytic conversion of biomass fast pyrolysis vapors was carried out on HZSM-5 with varying Si/Al ratios(ranging from 20 to 300) at 450 °C. The effects of Si/Al ratios of HZSM-5 zeolites on the distribut...In situ catalytic conversion of biomass fast pyrolysis vapors was carried out on HZSM-5 with varying Si/Al ratios(ranging from 20 to 300) at 450 °C. The effects of Si/Al ratios of HZSM-5 zeolites on the distribution of biomass fast pyrolysis products and carbon deposits on catalysts were investigated. It was quite remarkable that after in situ catalytic conversion the amount of light phenols and hydrocarbons increased significantly while that of heavy phenols decreased a lot. Besides, the yield of cyclopentenones with relatively low oxygen content generally increased. It also indicated that as the Si/Al ratios of HZSM-5 increased, the amount of hydrocarbons and light phenols was found to drop greatly. The amount of carbon deposits was found to be around 8.5% with the exception of HZSM-5 with the Si/Al ratio of 300,which is much lower. Moreover, the carbon deposits yield dropped gradually with increasing Si/Al ratios of HZSM-5.Calcination of spent catalysts at 600 °C helped to restore the catalytic activity to a large extent despite a relatively lower efficiency of deoxygenation. Results indicated that HZSM-5 with relatively high acidity displayed great catalytic performance.展开更多
In oil drilling processes,sand production in the oil layer is a common issue,generally mitigated by means of sand control screens.To prevent or reduce the risk of damage of these screens and to improve the related ser...In oil drilling processes,sand production in the oil layer is a common issue,generally mitigated by means of sand control screens.To prevent or reduce the risk of damage of these screens and to improve the related service life,it is necessary to investigate the related erosion dynamics.In this study,a screen mesh model based on the flow field similarity theory is proposed to overcome the otherwise too complex geometric structure of this type of equipment.Such model is optimized using experimental data.The predicted results are in good agreement with the measured values,and the error is less than 15%.The results also show that the simplified geometric screen model and the optimized Zhang et al.erosion model have high reliability;therefore,they could effective be used to select underground screen meshes and improve the design of production process.展开更多
基金supported by the National Basic Research Program of China(2013CB228104)
文摘In situ catalytic conversion of biomass fast pyrolysis vapors was carried out on HZSM-5 with varying Si/Al ratios(ranging from 20 to 300) at 450 °C. The effects of Si/Al ratios of HZSM-5 zeolites on the distribution of biomass fast pyrolysis products and carbon deposits on catalysts were investigated. It was quite remarkable that after in situ catalytic conversion the amount of light phenols and hydrocarbons increased significantly while that of heavy phenols decreased a lot. Besides, the yield of cyclopentenones with relatively low oxygen content generally increased. It also indicated that as the Si/Al ratios of HZSM-5 increased, the amount of hydrocarbons and light phenols was found to drop greatly. The amount of carbon deposits was found to be around 8.5% with the exception of HZSM-5 with the Si/Al ratio of 300,which is much lower. Moreover, the carbon deposits yield dropped gradually with increasing Si/Al ratios of HZSM-5.Calcination of spent catalysts at 600 °C helped to restore the catalytic activity to a large extent despite a relatively lower efficiency of deoxygenation. Results indicated that HZSM-5 with relatively high acidity displayed great catalytic performance.
基金the Foundation of the National Natural Science Foundation of China(No.51974033)Educational Commission of Hubei Province of China(Q20191310,D20171305).
文摘In oil drilling processes,sand production in the oil layer is a common issue,generally mitigated by means of sand control screens.To prevent or reduce the risk of damage of these screens and to improve the related service life,it is necessary to investigate the related erosion dynamics.In this study,a screen mesh model based on the flow field similarity theory is proposed to overcome the otherwise too complex geometric structure of this type of equipment.Such model is optimized using experimental data.The predicted results are in good agreement with the measured values,and the error is less than 15%.The results also show that the simplified geometric screen model and the optimized Zhang et al.erosion model have high reliability;therefore,they could effective be used to select underground screen meshes and improve the design of production process.
