Mechanism And Microcosmic Physical And Chemical Analysis Of Desulfuration At High Temperature During Coal Combustion

Energy and environment are the important insurance to the sustainable development of national economy and society. Coal is the main energy in China's energy structure. But coal is a kind of"not clean" energy. SO2from the coal combustion is one of the major air pollutants, leading to serious environmental pollution. It is urgent to control emissions of SO2. During all kinds of desulfuration technologies, desulfuration during coal combustion at high temperature is the most suitable one to our country because of its simple technology and low cost. But the rate is difficult to promote, which is well known. In allusion to this problem, the reaction mechanism and microcosmic physical and chemical analysis of desulfuration are studied thoroughly and systematically..Firstly, the reasons that influence desulfuration rate were analyzed based on the reaction mechanism of desulfuration and industrial conditions of coal combustion. Then three methods were put forward to promote desulfuration rate. That is to improve the desulfuration rate in the aspect of kinematics and thermodynamics and the course of sulfur fixation reaction.Secondly, the physical and chemical characteristics of all kinds of mineral materials and industrial waste were studied. And they were classified to five categories. Their chemical components and characteristic were analyzed by XRD. Their pore structure characteristics were analyzed by mercury porosimetry. Then based on the analysis of weight loss, the characteristic of calcinations and sintering of sulfur-retention additives and sorts of coals were studied in the view of analytical chemistry. That includes the analysis of crystal contents by XRD, pore structure by mercury porosimetry and surface forms by SEM. And the fractal dimensions of all calcined materials were calculated. Based on the data, the desulfuration rate of all kinds of additives were measured.Afterwards, the production mechanism of high temperature phase of sulphoaluminate was studied systemically. The influencing factors of the combustion temperature, retention period, the mix of compound, additive were obtained, and the forming mechanism was analyzed. The result of experiment indicates that the most of sulphoaluminate at 1300℃ and molar ratio 3:3:1 of compound were produced.At last, the factors that influence the desulfuration rate of industrial experiment were analyzed. And the microcosmic pore structure characteristic andvariation before reaction and after the reaction of all kinds of materials were analyzed. The model that describes the pore structure distribution was built and applied to the anticipation of desulfuration rate and optimized pore structure distribution successfully.