| Energy and the environment are facing a grim situation in recent China.Research and application of clean coal technology and dealing with solid waste from coal chemical industry are consistent with China's current national conditions,which are becoming important measures to build a recycling economy model and to achieve sustainable energy development strategy.Energy and chemical industry base in Ning Dong of Ning Xia province is one of the 14 national billon ton large-scale coal production bases.The annual production of solid waste is about 20 million tons in this base.In this paper,gasifier slag,combustion furnace slag and deactivated methanol catalyst were used to study the effect to coal combustion characteristics.The main results are as follows:1.Adding 0.1%,0.4%,0.7%,1%,1.5%and 2%of coal chemical industry wastes in coal and analyse the samples by thermogravimetric analyzer.The influence of these three waste on ignition temperature,burnout temperature,residual ash rate and maximum weight loss rate of coal combustion were investigated.The experimental results showed gasifier slag,combustion furnace slag and deactivated methanol catalyst reduced ignition temperature 35.45 ?,28.28 ? and 27.99 ? respectively,reduced the burnout temperature 69.15 ?,54.87 ? and 61.34 ?respectively,reduced residual ash rate by 6.50%,7.63%and 6.57%,and in all the three conditions above,maximum combustion rate were increased at the best content of chemical waste.At the same time the combustion characteristics such as combustibility index(Cb),stable burning index(G)and integrated combustion characteristic index SN of coal mixture with different content of chemical waste were analyzed.The results show that the Cb,G and SN values of the coal mixture are higher than coal.that is,these three waste material all have the positive contribution to coal combustion.The order is:gasifier slag>combustion furnace slag>deactivated methanol catalyst,the conclusion above is consistent with the results of the chemical waste effect to ignition temperature,burnout temperature and residual ash rate of coal combustion.2.The composition and content of these three wastes were analyzed by XRD and XRF.The results showed that the content of Fe2O3,Al2O3,CuO was the highest in gasifier slag,combustion furnace slag deactivated methanol catalyst respectively.The ash material after the reaction was analyzed by FTIR and SEM,it was found that the composition and structure of coal ash were changed after adding chemical waste.It can be deduced that the alkaline metal oxides and the metal elements undergo cyclic transformation under the action of carbon and oxygen in the process.3.The kinetics of combustion reaction was studied on the basis of thermogravimetric experiment,the results show that the chemical reaction order is 1 and the optimum heating rate is 10 ?/min.The waste can effectively reduce the activation energy of coal reaction of the first and second stages up to 14%and 10%.4.The effects of gasifier slag that held the best combustion effect on the combustion characteristics on six different coal samples combustion were investigated.It was found that coal chemical waste can improve the combustion characteristics of different coal,which is mainly related to the content of fixed carbon and oxygen in coal.The results of this study inferred that these three kinds of waste as a coal combustion agent have some certain feasibility in the process.This will not only realize the resource utilization of coal chemical waste,but also can improve the coal combustion efficiency,which will be conducive to energy conservation,to reduce energy consumption and relieve environmental pollution. |
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