重整生成油选择性加氢脱烯烃 Pd基催化剂的研究

 研究了负载在Al₂O₃载体上的贵金属钯(Pd)基催化剂在重整生成油选择性加氢脱烯烃反应中的性能。在高压微反装置上，采用环己烯、甲苯和正庚烷的混合物为模拟油来评价筛选催化剂，并对不同工业原料油进行加氢试验。结果表明，在现有工业上常用的工艺条件下，采用Pd/Al₂O₃催化剂进行重整生成油全馏分的选择性加氢，不能满足产品质量要求。其原因是高沸点馏分强吸附在催化剂表面，从而导致催化剂失活。在适宜的工艺条件下，采用Pd/Al₂O₃催化剂进行连续重整汽油BTX 馏分选择性加氢脱烯烃，可以使加氢汽油满足芳烃抽提进料的质量要求。添加助剂对Pd/Al₂O₃催化剂进行改进，可以大大提高催化剂的稳定性。改进后的双金属Pd基催化剂(Pd+M/Al₂O₃)可用于不同原料的重整生成油（苯(C6)馏分、BTX(C6~C9)馏分、全馏分）的选择性加氢脱烯烃反应。加氢反应产物的溴价小于200mgBr/100g，芳烃损失小于0.5%(质量分数)，且在重整生成油全馏分的选择性加氢过程中该催化剂表现出好的稳定性。

STUDY ON Pd-BASED CATALYSTS FOR SELECTIVE HYDROGENATION OF OLEFIN IN REFORMATE

The performance of selective hydrogenation for reformate over Al_2O_3 supported noble Pd-based catalysts was researched.The mixture of cyclohexene,toluene and n-heptane was used as model compound to evaluate and select catalysts,and the hydrogenation performance was tested with different industrial feeds.The results showed that in selective hydrogenation of whole fraction of reformate over Pd/Al_2O_3 catalyst the product could not meet the quality specification under the process conditions used usually in industrial plant,the reason of which was Pd/Al_2O_3 catalyst deactivation due to the adsorption of heavy components on the surface of catalysts.In the selective hydrogenation process of olefin removal from BTX fraction of reformate,the quality of hydrogenated gasoline satisfied the demand of aromatics extraction unit under suitable condition with the use of Pd/Al_2O_3 catalyst.The promoter was applied to modify the stability of Pd/Al_2O_3 catalyst in selective hydrogenation.The improved bimetallic Pd-based catalyst(Pd+M/Al_2O_3) could be used to process different feeds (benzene(C_6) fraction,BTX(C_6-C_9) fraction and whole fraction) for olefin removal reaction.The bromine value of product was lower than 200mgBr/100g and the loss of aromatics was less than 0.5%(mass fraction).And more importantly,the bimetallic Pb-based catalyst exhibited excellent stability in the process of selective hydrogenation of whole fraction reformate.