Shengwei Fan, Hongjian Tang*, Xiangqian Du, Weiyi Fan, Min Pan and Lunbo Duan*,
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引用次数: 0
Abstract
Circulating fluidized-bed flue gas desulfurization (CFB-FGD) is a widely employed semidry flue gas desulfurization technology due to its cost-effectiveness and easy operation. However, CFB-FGD cannot satisfy the ultralow emission requirement, particularly under high SO2-containing flue gas conditions. This study aimed to enhance the CFB-FGD performance in a cost-effective way by regulating Ca(OH)2 hygroscopicity in the desulfurization reaction. MgSO4 was screened out from 7 hygroscopic additives. With a minor addition of 4.8 wt % MgSO4, the sulfur capacity of Ca(OH)2 increased significantly by over 15% compared to its pristine benchmark. By synthesizing structural characterization and DFT calculations, the pros and cons of the H2O effect on the Ca(OH)2 desulfurization reactivity were revealed and discussed from an atomic perspective. X-ray diffraction suggested that the introduction of water could activate the Ca(OH)2 interlayer by expanding the interplanar distance in the (001) orientation, thus enhancing SO2 adsorption. DFT calculations showed that the desulfurization reaction over Ca(OH)2(001) was kinetically promoted in the presence of H2O by facilitating proton transfer. By contrast, excessively high hygroscopicity was found to inhibit the desulfurization performance of Ca(OH)2 by blocking porosity and hindering SO2 diffusion by absorbing redundant moisture. This work demonstrated that tuning Ca(OH)2 hygroscopicity is a low-cost and efficient way to boost SO2 sorption, which advances Ca(OH)2-based solution technologies for wider applications in the flue gas decontamination field.
期刊介绍：
Energy & Fuels publishes reports of research in the technical area defined by the intersection of the disciplines of chemistry and chemical engineering and the application domain of non-nuclear energy and fuels. This includes research directed at the formation of, exploration for, and production of fossil fuels and biomass; the properties and structure or molecular composition of both raw fuels and refined products; the chemistry involved in the processing and utilization of fuels; fuel cells and their applications; and the analytical and instrumental techniques used in investigations of the foregoing areas.
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