Research Of Presulfuration Sulfur-Tolerant Conversion Catalysts

Sulfide is a pretreatment process in the sulfur-tolerant shift catalyst with cobalt and molybdenum as the main active component, and pretreatment has a direct impact on the performance of the catalyst. At present, there are some shortcomings about sulfuration inside, for exmple, a long cycle and liquid sulfide is flammable, corrosion, toxicity, storage, transport difficulties and so on. The combination of organic sulfide and sulfur catalysts as the pre-curing agent, is an important pre-curing technology.This study focuses on pre-curing in the sulfur-tolerant shift catalyst. First, the use of straight-chain olefins and sulfur were synthesized as curing agent, then loaded the curing agent to the sulfur-tolerant shift catalyst; by analyzing sulfur content, the influence of temperature, reaction time, ratio of sulfur-alkene and other factors in the process of curing agent synthesis reaction, also optimized the curing agent and preparation conditions. Secondly, the use of atmospheric pressure micro-sulfur-tolerant shift reactor, investigation sulfuration conditions and activity of the pre-curing catalyst, while pre-curing catalysts were analyzed by SEM, DTA, XRD, etc. Finally, by Aspen plus CO shift conversion section was simulated and calculated in coal chemical industry to study the sulfur tolerant shift catalyst for practical application, the actual values were compared with simulated values of evaluation, and the simulation had an significance guidance.Experimental results show that the curing agent and organic curing agent prepared by mixing sulfide and sulfur olefin are feasible for tolerant shift catalyst. Preparation of curing agent suitable conditions:reaction temperature 170℃; reaction time 2.5h; sulfur-alkene ratio 1.8, in the conditions, the decomposition temperature is range, sulfur content as high as 24.19%and remain unchanged. Impregnated catalyst suitable conditions:impregnated temperature is 205℃; the impregnated time is 2h; sulfur and sulfide are 0.6 times by completely sulfuration; suitable vulcanization conditions:atmospheric.The characterization of pre-curing catalyst show that the pore volume and specific surface area had little change after vulcanization. The catalysts were analyzed by strength test, researching the status of catalyst particle deposition by using SEM photos, and crystal catalysts are characterized by XRD, active phase of aggregation does not appear in the vulcanized catalyst. Meanwhile, the thermal analysis of DTA and TG conducted on the catalyst, that catalyst curing exothermic peak is much lower than the curing. Key words:sulfur-tolerant shift catalyst; pre-vulcanization; organic sulfide; impregnated...