Mo/REHY催化剂的加氢脱硫性能

Hydrodesulfurization performance of Mo/REHY catalyst

将钼酸铵溶液与REHY等体积浸渍和焙烧,制备了Mo/REHY催化剂,采用XRD和NH_3-TPD对其进行表征。以质量分数0.6%的二苯并噻吩/正癸烷溶液为模型反应物评价其加氢脱硫性能。结果表明,不同焙烧温度制备的Mo/REHY催化剂,归属于REHY的晶相峰保持完好,金属活性组分Mo进入REHY体相超笼,引起REHY分子筛的弱酸和中强酸减少,强酸增加。焙烧温度520℃制备的Mo/REHY催化剂经过原位预硫化处理后,在反应压力4.0 MPa、空速40 h^(-1)、反应温度270℃、290℃和310℃时的二苯并噻吩加氢脱硫转化率分别达16.46%、43.21%和70.43%,较焙烧温度500℃制备的Mo/REHY催化剂,分别提高了1.56、6.47和2.83个百分点;继续升高焙烧温度,Mo/REHY催化剂二苯并噻吩加氢脱硫转化率基本相当。实验选择制备Mo/REHY催化剂的焙烧温度以520℃较为适宜。Mo/REHY催化剂二苯并噻吩加氢脱硫生成联苯的选择性约为2.7%,表明二苯并噻吩加氢脱硫的反应途径是以先加氢后脱硫的方式为主。

Mo/REHY catalysts were prepared by isometric impregnation methods and characterized by XRD and NH3-TPD methods. The hydrodesulfulrization（HDS） performance of the catalysts was evaluated using 0. 6wt% dibenzothiophene（ DBT）/decane as the model reactant. The results indicated that the crystal phase peak attributable to REHY kept well in Mo/REHY catalysts prepared at different calcination temperature. The active component Mo of Mo/REHY catalysts entered into REHY bulk, causing the weak and medium strong acid to reduce,and the strong acid to increase. The HDS conversion of DBT over the sulfided Mo/REHY catalyst calcined at 520 ℃ attained 16.46% ,43.21% and 70.43% respectively under the reaction conditions of reaction temperature 270 ℃ ,290 ℃ and 310 ℃, 4.0 MPa and space velocity 40 h^- 1, and increased by 1.56,6.47 and 2.83 percentage points compared with the catalysts calcined at 500 ℃. HDS conversion of DBT over Mo/REHY catalysts was almost equal with the increase of the calcination temperature. The optimum calcination temperature of Mo/REHY catalyst was 520 ℃. The selectivity to biphenyl from DBT HDS over Mo/REHY catalyst was about 2.7%, indicating that the pathway of DBT HDS reaction on Mo/REHY catalysts was based on the way of first hydrogenation and then desulfurization.