The Preparation Of Activated Carbon Based Desulfurizers And Its Desulfurization Capacity Optimization

Dry-method desulfurizers have many disadvantages to be solved,such as low desulfurizarion capacity and difficult regeneration,which limit the development of dry-method desulfurizers in the liquefied petroleum gas desulfurization industry.The activated carbon based desulfurizer is prepared by impregnation method,characterized by a variety of characterization methods to obtain structure parameters.Reaction conditions of desulfurization and regeneration are optimized.Addition of metals can improve desulfurization capacity of activated carbons significantly,especially the desulfurizer modified by Fe salts.Activated carbons can reduce iron species at high temperature.The amount of low valent ions species on the surface of desulfurizers increases with the increase of calcination temperature,which can enhance desulfurization capacity.The desulfurization capacity of iron species on the surface is decreased in the order of Fe>Fe3O4>Fe2O3.The addition of second metals can tune the desulfurization capacity.Cobalt can promote the reduction of iron metal species on activated carbon and decrease the reduction temperature of iron species,which improves the desulfurization capacity of desulfurization agents.The desulfurization capacity of MMAC-Fe/Co desulfurizer can reach 23.55%.Activated carbon based desulfurizer has abundant micropores and mesopores and the relationship between structure and desulfurization performance is as follows: The increased specific surface area of supports and the improved dispersion degree of metals can enhance desulfurization capacity effectively.Reaction velocity and temperature can significantly affect desulfurization performance of desulfurization agents.A small amount of water vapor and oxygen is essential to the desulfurization reaction,which can improve the desulfurization performance of desulfurization agents greatly.However,excessive water vapor and oxygen can't improve the desulfurization performance.According to studying the deactivation of desulfurizers,diethyl disulfide and Fe2(SO4)3 are the main sulfur species on the surface of desulfurizers.Diethyl disulfide adsorbed on the surface can be effectively removed by thermal regeneration under nitrogen atmosphere.When regeneration temperature is 400?,desulfurization capacity can almost be recovered.