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Coal is our most widely distributed reserves and consumption of primary energy, to solve coal-fired pollution problem, especially to reduce SO2 emissions, has become the important issues faced by the sustainable development of China. The coal desulfurization technology can be divided into three categories: in addition to sulfur fuel before combustion, burning sulfur capture and post-combustion flue gas desulfurization. Coal-fired Desulfurizer solid sulfur furnace technology, because of its desulfurization of less investment, low operating costs, the process is simple, very suitable for China's national conditions. However, the disadvantage of solid sulfur coal-fired process simple use of calcium-based desulfurization agent of the presence of calcium utilization rate is low, the desulfurization rate of sulfur release rate is inconsistent, Fixing Product easy to decompose at high temperatures, resulting in high temperature desulfurization efficiency is generally low . At home and abroad in recent years, researchers found that trace additives added can effectively improve the utilization of calcium-based desulfurization agent, thus greatly improving the sulfur capture efficiency at high temperatures, so screening efficient and inexpensive additives become a key issue for the coal-fired high temperature desulfurization research . Under laboratory conditions, the use of the tube furnace analog coal combustion process, and determination of the sulfur content of the flue gas, sulfur rate is calculated according to the amount of sulfur in the coal. Optimize the the solid sulfur conditions of the coal-fired based on a more systematic study of the impact of 1100 ℃ high temperature conditions, single-component, two-component and three-component composite additives on the the solid sulfur role of coal-fired. The many factors affecting coal-fired sulfur capture efficiency, this paper focuses on the temperature is set to 1100 ° C when Ca / S (calcium to sulfur molar ratio), the sulfur content of coal, residence time, coal particle size four the impact of factors on the sulfur capture efficiency of coal-fired, to determine the optimal experimental conditions. Ca / S, type of Desulfurizer, types of additives, and the additive added in an amount of four factors, selected on this basis the the solid sulfur orthogonal experiment, the results showed that: when the Ca / S is 2.0, in order to press the mass ratio of 2:3 mixing of CaCO3-Ca (OH) 2 the composite Desulfurizer as the main sulfur fixing agent, the amount of added sulfur additive set at 1.0% of the coal sample, the desulfurization efficiency. Has determined that the sulfur additive desulfurization conditions, the choice of eight common additives experimental study of single-component sulfur additives, compared role in promoting the strength of each single-component additive SULFATION . Experimental study was carried out on an experimental basis in a single component, respectively, K2CO3, SiO2, Al2O3-based sulfur additives of 3 groups of 16 two-component composite additives. The results showed that: K2CO3, and NaCl, Fe2O3 at a molar ratio of 0.2 mixing ratio; SiO2 and Fe2O3 according to the molar ratio is 1.0, and K2CO3 at a molar ratio of 5.0 mixing ratio; Al2O3 with NaCl at a molar ratio of 5.0, and ZnO. 1.0 mixing ratio at a molar ratio of sulfur rate are high, above 50%. On the basis of the above experiments, the rate for desulfurization and sulfur oxides generated out of sync and CaO and low utilization of sulfur capture efficiency, combined with the different roles played by the various additives in SULFATION, The three-component composite additives was investigated experimentally. Prepared by mixing different proportions of the three composite additive experiment and found that three-component composite sulfur additives selected coal desulfurization efficiency can reach more than 65%. To further verify that the ratio of three-component solid sulfur compound additives promoting role in the muffle furnace, the Add Compound Additives three coal sample depth Experimental Study of the type under high temperature conditions, the results show that K2CO3-Fe2O3-SiO2 , SiO2-K2CO3-NaCl, ZnO-Al2O3-NaCl compound additive has a good role in promoting coal desulfurization in the 1100 to 1200 ° C under high temperature conditions. Part of the ash solid sulfur product were characterized by XRD phase analysis to explore the mechanism of various additives for sulfur capture.
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