硫化温度对NiO/Al2O3催化剂的裂解C9烃选择性加氢性能的影响

以工业成型Al2O3为载体,采用分步浸渍法制备NiO负载量(w)为20%的NiOAl2O3催化剂,采用BET,XRD,XPS,TEM等方法对硫化态催化剂进行表征,以含有双环戊二烯(DCPD)和苯乙烯的甲苯-正庚烷溶液作为模型化合物,在10mL固定床加氢反应装置上考察了硫化温度对催化剂选择性加氢性能的影响。结果表明:在280~320℃硫化温度范围内,随硫化温度的升高,硫化程度先升高后降低,NiO/Al2O3催化剂适宜的硫化温度为300℃;在300℃硫化时,硫化镍晶粒的粒径较小,分散均匀;在反应温度180℃、压力3.5MPa、体积空速3.5h^-1、氢油体积比400的条件下,苯乙烯转化率达97.32%,DCPD转化率达94.78%,二氢双环戊二烯选择性达76.63%。

CHARACTERIZATION AND EVALUATION OF PRESULFURIZED NiO/Al2O3 CATALYSTS UNDER DIFFERENT SULFURIZATION CONDITIONS

The NiO/Al2O3 catalysts with 20% NiO loading were prepared by stepwise impregnation method with industrial Al2O3 as support. The sulfided catalysts were characterized by BET, XRD, XPS and TEM. The effect of presulfidation conditions on the selective hydrogenation performance of the catalyst was studied in a 10 mL fixed-bed hydrogenation reactor using toluene/n-heptane solution containing dicyclopentadiene (DCPD) and styrene as the model compound. The results showed that sulfidity increased first and then decreased with the increase of presulfidation temperature in the range of 280 -320 ℃. The optimum presulfidation temperature for NiO/Al2O3 catalyst was 300 ℃. The nickel sulfide grains were small and uniformly dispersed when sulfided at 300 ℃. At 180 ℃, 3.5 MPa, space velocity of 3.5 h-1, H2/oil volume ratio of 400:1, the styrene conversion was 97.32%, DCPD conversion was 94.78%, and DCD selectivity was 76.63%.