Study On Presulfiding Agent Of Hydrogenation Catalyst

Presulfurization is an important pre-treating process which the hydrogenation catalyst must experience, the result of pre-treating influence directly the catalyst's performance. The technique that uses organic sulfide and sulfur as sulfiding agent is an important developing direction of ex-situ presulfurization.The experiment presulfurized hydrogenation catalyst by three steps. Firstly, experiment synthesized sulfiding agent using straight-train olefin and sulfur as materials, the effect of the factors, such as reaction temperature, reaction time, ratio of sulfur to olefin and so on, on sulfiding agent's property was studied by means of analysis on sulfur content analysis. The process conditions were optimized by orthogonal test, and discomposed temperature of sulfiding agent was evaluated by means of TPR apparatus. Secondly, the hydrogenation activity of the catalyst was evaluated by means of model compounds and practical feeds in micro-reactor and 15ml reactor at high pressure, the process conditions of sulfiding agent and sulfur impregnation were studied. The impregnated catalyst was characterized by TPS, TPR, XRD and so on. Finally, the effect of H2 space velocity and temperature-programmed sulfiding on catalyst was studied by measuring sulfiding degree of catalyst.The results showed that it was feasible to ex-situ presulfurize hydrotreating catalyst by sulfiding agent and sulfur. The exothemicity of impregnated catalyst is not only little in air, but exothemicity is little and heat is dispersed during sulfurization. H2S concentration is much higher in effluent gas, if the effluent gas could be recycled, then sulfiding degree of catalyst is increased and resource is saved. The suitable conditions for preparing sulfiding agent were follows: reaction temperature is 170℃, reaction time is 2.5h, the ratio of sulfur to olefin is 1.8. Discomposed temperature of sulfiding agent prepared is wide at above condition, and sulfur content is 24.19% and it is stable. The suitable conditions for mixed sulfides impregnation were follows: impregnating temperature is 205℃, impregnating time is 3h, the ratio of sulfur and sulfiding agent to theoretical sulfur is 0.6 respectively, the ratio of solvent to catalyst volume is 0.6. The suitable conditions for sulfidation were follows: atmosphere pressure, H2 space velocity is 100h-1.