Experimental Study On Micro-Physical Chemistry Characteristics With Reactivity Of Blended Coal

The physical chemistry characteristics with reactivity of blended coal during thermal process is important for expounding optimizing coal blending. The blended coal studied in this paper is composed by two kinds of coal, anthracite and bituminous-coal which are quiet different in characteristic. We investigate the surface structure changing during the thermal reaction, and discuss the immanent cause of chemical reactivity transfer. TG/FTIR methods is used for studying the pyrolysis and combustion reaction mechanism, so as to predict the reactivity of blended coal in terms of kinetics. We analyze the dynamic emission of the pollutant during the piper heater combustion with blended coal to provide a theoretical basis for control the letting of sulfur and nitrogen oxide. We expand the application of optimal combination algorithm in coal blending to provide a theoretical and technical support for enhancing the time efficiency of the coal blending model.The microstructure and crystallite configuration parsing proved the blended coal may regard as a new kind of coal. Coal coke of blended coal was made in piper heater. Nitrogen adsorption and SEM methods were used to studying the microstructure of the coal coke. Changing of surface modality was discussed. The volatile constituent escaping and thermoplastic performance changing result in a lower specific area of the blended coal coke. The partial pore distribution changed with the ratio of the blended coal component. When the ratio of the anthracite and bituminous-coal in blended coal is 1:1, the mesopore distribution is same with that of anthracite coke. When the ratio of bituminous-coal is lower than 50%, the mesopore distribution of blended coal coke decreased with the increasing of bituminous-coal. When the ratio of bituminous-coal is higher than 50%, the mesopore distribution of blended coal coke increased with the increasing of bituminous-coal.TG—FTIR method was explored to analyze the gaseous product and kinetics for discussing the pyrolysis mechanism of blended coal. The temperature of the maximal pyrolysis rate changes little, which shows a structural similarity of blended coals. The volatile constituent emission characteristic curve has a multi-peak distribution and a wider half-peak, which show a relative unaided pyrolysis of constituent. It is not precise to elaborate the pyrolysis reactivity of blended coal containing anthracite by one-step-pyrolyze activation energy. Diffuse model and Chemical reaction model (n=6) can describe the pyrolysis process synthetically. Original pyrolysis temperature decreased linearly with the increasing of oxygen element content. The distribution and content of pyrolysis products have a close relationship with the element configuration and is affected directly by the ratio of the constituent.The blended coal combustion has a phase distribution. Sometimes, the ignition and burnout performance could not be improved at the same time because the heat distribution of the volatile constituent homogeneous combustion and blended coal coke non-homogeneous combustion is affected by oxygen partial pressure. The combustion time of 50% organic matter of blended coal is similar to that of the bituminous-coal. When the ratio of the bituminous-coal raged from 33.3% to 66.7%, the blended coal has a better ignition and burnout performance. The infra-red analysis of the combustion gaseous products shows that the relatively conversion rate of carbon to CO/CO₂ will be affected by carbon distribution in pyrolysis products and have a close relationship with combustion atmosphere.In order to control the pollution of blended coal combustion, we should analysis the dynamic emission of nitrous and sulfur pollutant. Under the combustion condition of piper heater, the effect of oxygen concentration on generation rule of NO and SO₂ was investigated. The NO dynamic emission curve was changeful. Lower oxygen concentration will inhibit the translation of volatile-nitrogen into NO, and strengthen the translation of char-nitrogen into NO under some circumstance. NO peak location has biggish fluctuation with blend ratio, so must pay more attention to air-condition combustion. The dynamic emission curve of SO₂ has a bimodal distribution, and the SO₂ yield increase with the increasing of oxygen concentration. The SO₂ gross has a linear relationship with sulfur element content.The development of on-line measurement technology proposes a higher require on the time efficiency of coal blending model, which can be achieved by Object Oriented Programming and combinatorial optimization algorithm based on evolution idea. By the combination of genetic algorithm and data coding, and utilizing heuristic search mechanism, the higher-time-consuming problem for multi-coal selection and high-precision coal blending can be solved, even though it could decrease the quality of the optimum solution. By utilizing the succession of class effectively, the Object Oriented Programming can realize the algorithm improvement and extension, so as to facilitate the popularization and application of the coal blending model.