Study On Adsorption Of Hydrogen Sulifde Gas By Modified Oil Shale Semi-coke

In recent years, oil shale, as an important supplement energy, caused worldwideconcern with its huge reserves and the comprehensive utilization. The semi-coke afterthe oil shale retorting and reifning is not a entire product of pyrolysis, which containsrich hydrogen, and oxygen elements. Atfer volatiles release, the semi-coke made richpore space and specific surface area, which provided favorable conditions formodified adsorbent.The pollution caused by the fossil development and the utilization in the processcannot be ignored, arid the sulfide pollution is particularly serious in the number ofpollutions. Hydrogen sulfide is a toxic, harmful and strong pungent odor gas，whosewide presence can make catalysts deactivate completely and seriously corrode metalpiping, equipments. In addition, the Hydrogen sulfide of natural gas bums into SO2,forming acid rain to pollute environment.In this paper, the Jilin Huadian oil shale semi-coke is taken as the research object,which made a studied of its physical chemistry and adsorption properties are studied,the main are contents as follows:From the physical chemistry and adsorption properties of semi-coke, the volatilecontent constantly declining and ash content increased with ifnal temperature rising.The characteristic parameters of semi-coke such as surface characteristics materialcomposition, porosity changes were obtained by XRD, SEM, BET specific surfacearea, BJH cumulative pore area.The capacity of H^S removal and effects of H₂S removal activities forsemi-cokes were investigated in fixed bed reactor in simulated raw gas. The factorssuch as particle size of the adsorbents, different modification methods, chemicalcharacteristics of surface, concentration of H₂S would affect the removal of H₂S. Theresults indicate that adsorption capacity for oil shale and raw semi-cokes are very low, with the rising of final pyrolysis temperature the adsorption capacity of semi-coke hasincreased. The raw semi-cokes contained few surface acid-base properties, but themodification increased the surface acid-base properties and adsorption capacity. It isfound that the adsorption capacity has not linear relationship with the content ofsurface acid-base properties. The raw semi-coke modified by three differentconcentrations of NaOH solution and the best adsorption is modiifed by10%NaOHsolution, which adsorption capacity reached15.49mg/g, the breakthrough time of1lOmin. The semi-coke which is modified by NaOH solution has better adsorptioncapacity then HNO₃solution. The expeirmental study also found that lowconcentrations of H₂S and the particle size of0.5-1mm has pretty well performancefor H₂S adsorption.Finally, to study the regeneration capacity of the semi-coke, water regenerationand thermal regeneration have been used for the spent modified semi-cokes whichhad removed H₂S. The result showed that the effect combined thermal regenerationwith water was better than water regeneration.