Study On The Coal Desulfurization By Micmwave Chemistry Method

In this paper,the effect of desulfurization of high-sulfur coals from Wuhai,Beisu and Xinyu by microwave chemistry method for organic sulfur removal and heat treatment of Fe2(SO4)3 for inorganic sulfur removal were investigated.The changes in the physic-chemical and caking property of coal after desulfurization were investigated as well.The mechanism of desulfurization by microwave method was analysised by FTIR,XPS and ion chromatography.The result shows that pyrite of coal can be removed effectively by Fe2(SO4)3.The removal of pyritic sulfur could be inhanced by increasing concentration of Fe2(SO4)3,increasing reaction temperature,prolonging reaction time or decreasing particle size of coal.14?68%of pyritic sulfur can be removed under the experimental conditions of this article.The caking index and dilatation of coal decreased in defferent degrees after desulfurization.The organic sulfur of coal was removed effectively by microwave chemistry method with the media of NaOH.The organic sulfur removal can be improved by prolonging reaction time,increasing microwave power,rising reaction temperature or using the oxidizing atmosphere.With the increase of the concentration of NaOH,the removal of organic sulfur from coal increased at first and then decreased.That's same as the change of the imaginary part of dielectric constant of NaOH solution with the increase of the concentration of the solution.66.4%of organic sulfur was removed under the experimental conditions of this article.The removal of organic sulfur improved with the increasing of the imaginary part of the dielectric constant of chemical additives under the condition of microwave radiation.The caking index decreased as the increasing of reaction time and rising of temperature until it was completely lost.The organic sulfur of XY2#was removed by 34.39%when microwave power was 385W,reaction time was 15min and concentration of NaOH was 10%and the caking property of coal was still strong.82.76%of thioalcohol and thioether,67.74%of sulfone,32.76%of sulfoxide and only 11.90%of thiophene was removed by microwave method when the microwave power was 385W,reaction time was 30min and concentration of NaOH was 10%.88.8%of the total removed organic sulfur existed in filtrate as S2-and SO42-after desulfurization by micmwave chemistry method.Other 11.2%of the total removed organic sulfur converted into gas during the desulfurization.