大孔径石蜡加氢精制催化剂的制备

Preparation of Catalyst with Support of Macro-Pores for Paraffin Wax Hydrofining

采用氨吸附-程序升温脱附(NH3-TPD)、低温N2吸附(BET)、压汞法以及加氢精制活性评价等技术,探索SiO2-Al2O3载体在制备过程中孔结构和表面性质的变化。实验结果表明,采用特殊扩孔剂制备载体,当焙烧温度为700℃时,平均孔径可达到17.3nm,其中孔径大于20nm的孔占总孔体积的13.2%;同时载体表面上的中、强酸中心也全部丧失,均为弱酸中心。采用该载体制备的MoNiP/SiO2-Al2O3石蜡加氢精制催化剂,在MoO3用量减少了约1/4的情况下,比目前工业上使用的催化剂具有更高的脱金属能力和加氢精制活性。

Catalyst support SiO2-Al2O3 was prepared by using special pore-enlarging agent and being calcinated at 700°C. Changes of its pore structure and surface properties were studied by means of NH3-TPD, BET, and mercury intrusion method. The activity of catalyst was evaluated in a bench-scale reactor. Mean pore diameter of the support was 17.3 nm and volume fraction of pore with diameter of more than 20 nm accounted for 13.2%. After calcination at 700°C, acid sites on support surface were all of weak acidity. MoNiP/SiO2-Al2O3 catalyst with this support showed higher demetallization ability and higher paraffin wax hydrofining activity than current commercial catalyst in use, despite loading amount of MO2O3 was only 3/4 of the commercial.