【摘要】 采用光学显微镜表征了水溶性分散型催化剂在渣油中的分散过程,并应用激光粒度分析手段研究了分散过程的影响因素,同时考察了各分散条件对辽河减压渣油(LHVR)悬浮床加氢反应结果的影响。结果表明,降低渣油-水溶性催化剂分散体系的油-水界面张力(λ)能显著地提高催化剂的分散度,且在一定范围内,催化剂颗粒的平均粒径与λ呈良好的线性关系。降低渣油-水溶性催化剂分散体系的油-水界面张力,可显著提高催化剂的抑焦活性,使裂化生成的大分子自由基能迅速地加氢湮灭,从而阻碍缩合生焦反应的进行;同时可提供更多的焦炭沉积载体,阻止团块结构焦粒的形成,降低焦炭颗粒尺寸,使焦炭较均匀地分散在液相产物中。增加水溶性催化剂分散过程中的剪切速率或降低催化剂前体溶液浓度,也能提高催化剂的分散度,提高催化剂抑制缩合生焦的能力,但其效果远不如油-水界面张力的效果。更多还原

【Abstract】 The optical microscopy was adopted to characterize the dispersion process of water-soluble catalyst in residue for the slurry-bed hydrocracking of residue.The factors influencing the dispersion process were studied by using the laser particle analysis,and the reaction results of Liaohe vacuum residue(LHVR) under different dispersed conditions were investigated at the same time.The results indicated that the dispersity of water-soluble catalyst in the dispersion system was significantly improved by reducing the oil-water interfacial tension(λ) of system in the dispersion process,and a good linear correlation was obtained between the average size of catalyst particles and λ in a certain range.Reducing the oil-water interfacial tension could enhance the activity of catalyst to inhibit the formation of coke significantly,and quickly lead to the annihilation of macromolecular free radicals generated by thermal cracking,thus preventing the condensation reaction for coke.At the same time,increasing the dispersity of catalyst could afford more carriers of coke deposition to prevent the agglomeration of coke particles,and the particle size of coke was reduced significantly so that coke could be better suspended in liquid products.The dispersity of catalyst could be improved and the ability of catalyst to inhibit coke formation could be enhanced also by increasing the shearing rate or reducing the concentration of precursor solution,but this effect was much less than that of oil-water interfacial tension.更多还原