以大孔容TiO_2和大孔容Al_2O_3为混合载体的加氢脱氮(HDN)催化剂的研究

STUDIES OF HDN CATALYSTS SUPPORTED ON TiO_2 AND Al_2O_3 BOTH WITH LARGE PORE CAPACITY

把一定量的大孔容Al2 O3和TiO2 粉末混合均匀 ,用稀HNO3调匀挤成条状。测其吸水率 ,用等体积浸渍法负载固定含量的活性组分 (NiO和WO3) ,制备出Ni-W TiO2 -Al2 O3型催化剂。利用固定床流动反应器评价催化剂的HDN活性。结果表明 ,选择一定配比的TiO2 和Al2 O3作为混合载体 ,与以单一的Al2 O3为载体所制得的Ni-W催化剂相比 ,其HDN活性要高。而且 ,适当的予硫化条件、较低的焙烧温度有利于提高催化剂的HDN活性。

WT4”BZ]A series of supports mixed with TiO 2 and Al 2O 3 by large pore capacity were extruded into strips A series of supported NiW catalysts were prepared by impregnating (equal volume method) such supports simultaneously with aqueous solutions of (NH 4) 6H 2W 12 O 4 and Ni(NO 3) 2·6H 2O with appropriate concentration The evaluation of catalytic activity for 3-methyl pyridine HDN was carried out in a continuous flow reactor under 3 0 MPa and 350℃ Compared with NiW/Al 2O 3, NiW/TiO 2-Al 2O 3 catalyst with a definite ratio of TiO 2 and Al 2O 3 had a higher activity for HDN On the one hand, this was maybe caused by the difference of acidity of TiO 2 and Al 2O 3 On the other hand, the reductivity of TiO 2 enhanced the catalyst's sulfuration In addition, different sulfuration LHSV could influence catalyst's HDN activity, and LHSV of 0 8h -1 had better activity and stability than that of LHSV of 0 2h -1 A lower calcination temperature over catalyst could increase its HDN activity [WT4”HZ]