CoMoS/γ-Al2O3催化剂对麻疯树油加氢处理的研究

采用硫代硫酸铵器外预硫化制备CoMoS/γ-Al₂O₃催化剂,采用XRD、N₂物理吸附、NH₃-TPD、XRF等手段对催化剂进行表征,通过固定床微反装置研究其对麻疯树油加氢处理的性能。考察了硫化度、反应温度、氢气压力、反应时间对催化剂活性与催化产物分布的影响,并探讨了麻疯树油甘油三酯的反应路径。结果表明,硫化度为1的CoMoS₁/γ-Al₂O₃催化剂活性最佳,在温度360℃、氢气压力3 MPa条件下,对麻疯树油转化率为96.3%,产物主要成分C_15~18正构烷烃收率为75.6%,比相同条件下非硫化CoMo/γ-Al₂O₃催化剂的转化率提高36.9%。反应温度升至420℃时,CoMoS₁/γ-Al₂O₃催化剂对麻疯树油转化率达100%,产物中无含氧物。麻疯树油加氢处理过程中,增大硫化度和反应温度、减小氢气压力有利于甘油三酯发生加氢脱羧、脱羰反应。

Hydrotreatment of jatropha oil over CoMoS/γ-Al2O3 catalyst

CoMoS/γ-Al₂O₃ catalysts were prepared by ex-situ presulfiding method using ammonium thiosulfate as a sulfiding agent and characterized by XRD, N₂ physisorption, NH₃-TPD and XRF techniques. The catalytic performances were tested by hydrotreatment of jatropha oil in a fixed-bed reactor. The effects of sulfidity, reaction temperature, hydrogen pressure and reaction time on catalyst activity and catalytic product distributions were investigated. Reaction pathways for the hydrotreatment of jatropha oil were also discussed. The results showed that the CoMoS₁/γ-Al₂O₃ catalyst with a sulfidity of 1 had the best hydrotreatment activity, showing 96.3% conversion of jatropha oil and 75.6% yield to the main components of C_15~18 n-alkanes at temperature 360℃ and hydrogen pressure 3 MPa. Its conversion was 36.9% higher than that of the non-sulfided CoMo/γ-Al₂O₃ catalyst at the same reaction conditions. It is worth noticing that both of the conversion of jatropha oil and the total oxygen-free compound of products could achieve 100% over CoMoS₁/γ-Al₂O₃ at 420℃, 3 MPa. With the increase of sulfidity and reaction temperature or the decrease of hydrogen pressure, the hydrodecarboxylation and hydrodecarbonylation were enhanced.