Fundamental Research Of High-Temperature Phase Desulfurization During Coal Combustion

In allusion to the problems which is well known that the desulfurization rate is difficult to promote and traditional desulfuration production CaSO4 is easy to decompose during coal combustion at high temperature in furnaces, the fundamental experiments and theories research of high-temperature Stable Phase desulfurization were developed systematically. The formation and decomposition of high-temperature stable phase desulfurization were studied at laboratory-scale batch system, and the reaction mechanism were analyzed thoroughly combined X-ray diffraction , SEM visualization and TG/FTIR, then the thermodynamics, kinematics and the forecast models were established.Firstly, the emphasis of this study is on the property formation mechanics and influencing factors of high temperature phase of sulphoaluminate during coal combustion of extensive used grate-fired furnace and pulverized coal fired boiler. The formation and decomposition of Phase sulphoaluminate was studied at tube furnace and high temperature laboratory-scale batch system. At the same time, the formation rule and influencing factors of sulphoaluminate at different atmosphere was studied.First introduce the reaction thermodynamics and kinematics theory into high temperature phase of sulphoaluminate. There is no conclusion about thermodynamics and dynamics of sulphoaluminate because the pure sulphoaluminate is difficult to obtain. This article first get the thermodynamic parameter of sulphoaluminate by approximation method based the research productions of inorganic compound thermodynamic parameter. The thermodynamic results accord with experiments data and predecessor achievement. First utilize the thermal analysis to study the formation kinematics of sulphoaluminate based on competitive reaction.Cause the characteristic of coal has mineral itself, we research the desulfuration of eight kind of coal. Cause the mineral of the coal can be the material of desulfuration, so the cost of desulfuration can be reduced. Through the reach of the mixture of the coal and it's ash and the coal and additive, we find the rules of affect the formation of sulphoaluminate. Through the XRD and SEM we can illustrate the mechanism of the formation of sulphoaluminate in the ash of coal.We research the formation and oxidation thermodynamics and kinematics of desulfuration intermediate product CaS aim at grate-fired furnace andpulverized coal fired boiler, and research the influence of air and CO2 to the oxidation character of CaS in the high temperature and in different atmosphere at laboratory-scale batch system. CaS formation character of five typical coal at CO2 were studied.To the characteristic of the data of experiments, we combine the gray theory and desulfuration in high temperature for the first time. By the gray unite analyse to the formation and separate of sulphoaluminate and CaS, we find the influence factors of the reaction and eatablish the model of gray forecast to the formation of sulphoaluminate and the seperate of CaS.The technical application of high-temperature phase desulfurization at two stage desulphurization were discussed. The viewpoint was clarified that the formation of sulphoaluminate and CaS can improve desulfurization rate of two stage desulphurization ulterior, therefore there is great potential value for high-temperature phase desulfurization. By the research of the dregs after desulfuration ,we can find the dregs is very usefull.