Hydrogenation Catalysts For Sulfide Passivation Process Research

The actuality and foreground of the passivation technology inland and abroad were reviewed. The prosperty and activity of the passivation catalyst were studied. The effects of the factors, such as temperature, O₂ concentration, passivation time, space velocity and so on, on the catalyst passivation in fixed bed.The passivation catalyst in fixed bed was evaluated by sulfiding degree and the highest self-heating temperature. The results showed the suitable conditions were follows: temperature = 50℃, O₂ concentration = 1%, time = 30 min and space velocity = 1000h-1. On the basis of said conditions, the ex-situ expansion bed process for passivation catalyst was investigated. The effects of the factors including temperature,O₂ concentration,passivation time and expansion rate ect, on catalyst passivation. The suitable conditions were follows: temperature = 50℃,O₂ concentration = 1%, time = 30 min and expansion = 12%. Compare to in-situ CS₂ presulfiding process, the activity and stability of the catalyst presulfiding by ex-situ expansion bed was better. Furthermore, the liquid passivating technology was studied. Several different liquid passivating material were selected and the effects of temperature﹑stiring time as well as the oil/cat ratio on the performance of the passivation catalyst were investigated. The results indicated that the proper reaction conditions were :the reaction temperature was 40℃, the stiring time = 10 min and the oil/cat ratio = 1/13. The specific surface﹑the bulk and the distribution of the pore were charactered. The intensity test and SEM was carried out The crystalline phases of the catalyst were charactered by XRD. At the same time, the thermal analysis of the catalyst was carried out by DTA,TG. The exothermic peaks of the passivated catalyst was much lower than the sulfided catalyst. The acidity and the reducibility of the catalyst were charactered by pyridine-TPD and TPR. The results indicated that the acidic intensity of catalyst was: passivation> sulfide >oxide. The reducing peaks of the oxide catalyst is obviously less than sulfide catalyst, while the peaks of the passivated catalyst was much less than the former two.