正戊烷异构化催化剂活性组分

Effect of loaded metals on reactivity of catalyst for pentane isomerization

采用连续流动式固定床高压微反—色谱联合装置,考察了氧化镍、氧化钼含量对正戊烷加氢异构化镍—钼—氢型丝光沸石(Ni-Mo-HM)催化剂反应性能的影响。引入助剂Mo可以提高催化剂的性能。Ni-HM,Ni-Mo-HM催化剂上的正戊烷异构化遵循典型的双功能催化反应机理,在低镍含量时,金属活性中心上的加脱氢为速度控制步骤;高镍含量时,酸中心上的正碳离子骨架异构反应为速度控制步骤。HM3321催化剂上的实验表明,在较适宜的工艺条件下,正戊烷转化率为67.2%,异戊烷收率为62.2%,异戊烷选择性为92.5%,液体产物收率为96.1%。实验结果表明,Ni-Mo-HM催化剂可以作为正戊烷异构化催化剂,性能优于Ni-HM催化剂。

Effect of loaded Nickel and Molybdenum contents on the reactivity of modified mordenite Ni-Mo-HM for pentane isomerization in the presence of hydrogen is investigated by a continuous flow high pressure fixed-bed microreactor-chromatography unit. The reactivity of Ni-HM catalyst can be improved by addition of Molybdenum. Pentane isomerization over Ni-HM and Ni-Mo-HM catalysts follow the typical bifunctional catalytic reaction mechanism. At low loading of Nickel, hydrogenation and dehydrogenation on metal sites of the catalyst are the rate control steps while at high content of Nickel, carbonium skelton isomerization on acidic sites becomes the rate control step. Results from runs over HM3321 catalyst show that the proper reaction conditions are as follows and under these conditions n-pentane conversion, iso-pentane yield, iso-pentane selectivity and liquid product yield are 67.2 %, 62.2 %, 92.5 % and 96.1 %, respectively. The experimental results prove that for pentane isomerization Ni-Mo-HM catalyst is suitable,the properties of which are superior to those of Ni-HM catalyst.