Study Of Catalyst And Technology For Hydrogenation Of Reformed Raffinate Oil

Reformed raffinate oil can be used for ethylene cracking feedstock or 6# solvent oil after hydrogenation of the unsaturated hydrocarbon. Until now, most of the catalysts which were used for hydrogenation of olefins are Ni-Mo catalysts. So far, the catalyst which was applied to low pressure (less than 1MPa) hydrogenation reaction has not been reported. There are two kinds of catalysts used for aromatic hydrogenation, Ni-based catalysts and Pt-based catalysts. Pt-based catalysts gain more and more people's attention because of their well stability, large space velocity and other advantages. But Pt is scare resource, price is expensive, how to optimize the Pt dispersion to improve the efficiency of the catalyst has become an urgent problem to be solved.A series of Ni-Mo-P/γ-Al₂O₃ catalysts which were used for reformed raffinate oil hydrogenation to produce ethylene cracking feedstock were prepared by changing the content of active component.The Ni-Mo-P/γ-Al₂O₃ catalysts were characterized and evaluated to determine the appropriate content of active component. The result showed that: The optimum active components content of MoO3 =20%, NiO =3.8%, P =1.24%.The optimum process conditions of Ni-Mo-P/γ-Al₂O₃ catalysts used for the reformed raffinate oil hydrogenation to produce ethylene cracker feedstock were determined by investigating the effect of process conditions on the hydrogenation activity of catalysts. The optimum reaction temperature was 240℃, pressure w as 0.5M Pa, hydrogen oil ratio w as 100:1, liquid hourly space velocity was 2.0h-1.A series of Pt catalysts used for the reformed raffinate oil hydrogenation to produce 6# solvent oil were prepared using chloroplatinic acid as precursor of Pt. The support of Pt/Al₂O₃ catalysts was modified by Ti. The result showed that Ti decreased the acidity of support and promoted the reduction and dispertion of Pt which was beneficial to improve the hydrogenation activity. The optimum support calcination temperature of Pt/Al₂O₃-TiO₂ catalysts was 900℃which was determined by investigation of support calcination temperature.The preparation method of Pt/Al₂O₃-TiO₂ catalysts was investigated. The result showed that, both the calcination temperature of catalysts and the species of competing sorbent added to the impregnating solution had effect on the dispertion of Pt. The optimum preparation method of Pt/Al₂O₃-TiO₂ catalysts which was studied by comparing the hydrogenation activity of catalysts was that the catalyst was calcinated at 35℃0 using hydrochlor ic acid as competing sorbent. Thus Pt on the catalyst presented in thick-shell-type.The optimum process conditions of Pt/Al₂O₃-TiO₂ catalysts for the reformed raffinate oil hydrogenation to produce 6# solvent oil were determined by investigating the effect of process conditions on the hydrogenation activity of catalysts. The optimum reaction temperature was 200℃, pressure w as 3.0M Pa, hydrogen oil ratio w as 200:1, liquid hourly space velocity was 3.0h-1.