ZSM-5硅烷化改性对临氢降凝催化剂的影响

Effect of ZSM-5 silanization modification on hydrodewaxing catalyst

采用液相沉积法对ZSM-5分子筛进行硅烷化改性,以改性后的分子筛为原料制备了变压器油临氢降凝催化剂,通过N_2-BET、NH_3-TPD和By-IR等方法对催化剂进行表征。以环烷基原油加氢改质柴油为原料油,在固定床反应器上对催化剂进行性能评价。结果表明,通过控制SiO_2的沉积位置和沉积量,可以降低外表面酸性、修饰孔口尺寸,阻止非择形裂解反应,提高反应的择形性能。在反应温度280℃、压力8 MPa、空速1.0 h^(-1)和氢油体积比500∶1的条件下,使用自制的催化剂,可得到倾点小于-50℃的40~#变压器油馏分。

Silanization of ZSM-5 molecular were prepared by liquid deposition method.Then hydrodewaxing catalyst for transformer oil was prepared from the modified zeolite,and characterized by N 2 -BET,NH 3 -TPD and By-IR.The performance of catalyst was evaluated in a fixed-bed reactor using naphthenic hydro-upgrading diesel as raw material. The results show that by controlling the deposition position and deposition amount of SiO 2 ,outer surface acidity can be reduced, pore size can be modified,and the non-shape selective pyrolysis reaction can be prevented so as to improve shape-selectivity.Using this catalyst,the 40# transformer oil with pour point less than -50 ℃can be obtained under the conditions of reaction temperature 280 ℃,pressure 8 MPa,space velocity 1.0 h -1 ,and hydrogen to oil volume ratio 500 ∶ 1.