超细负载型Ni-Mo/Al2O3催化剂在渣油加氢裂化中的应用

针对渣油固定床加氢工艺催化剂易结焦失活以及悬浮床加氢工艺催化剂活性偏低的问题,将能悬浮在渣油中的超细负载型催化剂(Ni-Mo/Al2O3)应用于渣油的加氢裂化反应,并在高压釜中考察了反应条件对新疆减压渣油(XJVR)转化率的影响,其中催化剂添加量(质量分数)的考察范围为1%～10%、反应温度为410～450℃、反应时间为0.5～2.5 h、氢气初始压力为5～9 MPa。结果表明,催化剂的添加量对渣油、沥青质以及残炭转化率的影响都很小,但增加催化剂添加量能明显地促进硫的转化,即在此催化体系下,渣油的裂化反应以热反应为主,而加氢脱硫反应则由催化剂的活性中心所决定;反应温度对渣油、残炭、沥青质以及硫的转化率的影响较大,随着反应温度的提高,渣油、残炭、沥青质以及硫的转化率都呈上升的趋势,且前三者的上升趋势更为显著;延长反应时间对反应转化率的影响与提高反应温度所得到的结果类似;当氢气严重过量时,再提高氢气压力对硫转化率没有影响,但可在一定程度上促进残炭和沥青质的加氢反应。

Application of ultra-fine supported Ni-Mo/Al2O3 catalyst in residue hydrocracking

To find a solution to easy catalyst deactivation of fixed-bed residue hydrotreating process and low catalyst activity of suspended-bed residue hydrotreating process,the ultra-fine supported Ni-Mo/Al2O3 catalyst which could be suspended in residue oil was applied in the residue hydrocracking reaction,and impact of catalyst dosage(mass percentage) on the conversion rate of Xinjiang vacuum residue(XJVR) was investigated in a HP autoclave at conditions of 1%-10% catalyst dosage,410-450 ℃ reactor temperature,0.5-2.5 hours reaction time and 5-9 MPa initial hydrogen pressure.The results show that the dosage of catalyst addition has little impact on the conversions of residue,asphaltenes and carbon residue;Whereas,increased addition of catalysts will markedly promote the conversion of sulfur.In this catalyst system the thermal reaction prevail in residue cracking reaction,and hydrodesulfurization reaction is decided by the active sites of catalysts;The reaction temperature has a greater impact on the conversions of residue oil,carbon residue,asphaltenes and sulfur;With rising reactor temperature,the conversions of residue oil,carbon residue,aslphaltene and sulfur will increase,especially the conversions of residue oil,carbon residue and asphaltenes;Extending the reaction time has similar impact on reaction conversion as raising the reaction temperature;At an excessive hydrogen make-up,increasing hydrogen pressure has no impact on sulfur conversion,but will promote the hydrogenation reaction of carbon residue and asphaltenes to a certain extent.