| China is one of the most abundant coal reserves of the country,however,coal combustion will bring serious environmental pollution.Compared with the traditional low efficiency of wet FGD technology,integrated gasification combined cycle power generation(IGCC)is a high efficiency and low emission clean coal-fired power generation technology,it consists of two main processes: one is coal gasification process,the second is a gas-steam combined cycle processes.IGCC technology use coal resources efficiently and cleanly,and the high temperature coal gas desulfurization technology is the key of gas purification,desulfurization agent is suitable for the important topics in the field of high temperature steam desulfurization.Choose of support of sorbent.Mental oxides,which are widely used as sorbents to remove H2 S,suffer from several problems such as low sulfur capacity,easy sintering,low desulfurization precision,low mechanical strength and difficult regeneration.In order to avoid the occurrence of these problems,the metal or metal oxides can be loaded on the support with strong stability.The different R/C ratios of three-dimensional porous carbon aerogels have been prepared by the sol-gel,ZSM-5 and carbon aerogels with high pore volume and specific surface area,so that gas diffusion is more efficient and desulfurization performance is good.The iron-based as active phase loaded on carbon aerogels and ZSM-5 respectively,with ultrasonic impregnation by different mass ratios,different R/C ratios of carbon aerogels as the support of the desulfurization agent and under different calcination temperature conditions were obtained.Activity of various desulfurization agent was evaluated in a fixed bed reactor under different temperature and atmosphere,and the sulfidation and regeneration behavior research were also evaluated.Fabrication and performance of sorbents.Study found that using ultrasonic impregnation preparation of iron-based sorbent can make the iron or iron oxide active component uniform distribution in carbon aerogels with surface or the pore and form much pore and large surface area of the structure.The BET specific surface area test revealed that the carbon aerogels calcined at 950 ? can ensure strong mechanical strength at high temperature.Through the analysis of XRD patterns,we found the main active phase is Fe nanoparticles when carbon aerogels as support,however,the active phase is Fe3O4 in nitrogen condition of 600?.When calcined at 600? tubular furnace in air condition,the active phase is Fe2O3,but the BET specific surface area obtained carbon aerogel is very little because of the completely reaction with air.The active phase obtained by calcination of ZSM-5 support is Fe2O3.The results showed that carbon aerogels support could not be calcined under the oxygen conditions.What's more,C100 support had lower sulfur capacity and reaction rate than C300,C500 and C700 support,because of its mainly micropore structure,and the larger the R/C ratios are,the larger the surface area and pore volumes of carbon aerogels,therefore,we chose C700 as the support.We adopt ultrasonic impregnation to prepare the sorbents with different mass ratio(30%?50%?70%)of iron,and the sulfidation performance test were implement in the 550-650 ?.600 ? is the best temperature for 50%Fe/C700 sorbent desulfurization performance,the sulfur capacity is 12.54g/100 g sulfur.50%Fe/ZSM-5 sorbent desulfurization breakthrough time is generally short,the sulfur capacity and the deactivation rate is smaller.When the atmosphere contains H2,only the active components of Fe nanoparticle was not affected,other active components sorbents were significantly restrained.Five consecutive sulfidation(600?)-SO2 regeneration(700 ?)cycle test results showed that the 50%Fe/C700 sorbent had good regeneration performance stability.In summary,the paper focuses on investigating the performance of Fe-based/carbon aerogels sorbent at reduction,sulfidation and regeneration process using TG,fixed bed,and H2-TPR technique.The characterization techniques such as the BET surface area,pore volume and the pore diameter distribution,XRD,XPS,SEM,TEM were used to analyse the micrography structural and textual changes of sorbent at calcination,sulfidation and regeneration process.And the sorbent with same active phase different support,different active phase with the same support were researched.We found that a sorbent with high stability,sulfur capacity and anti-hydrogen ability under high temperature,which provides a new research direction and field for high temperature desulfurization in the future. |
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