The Research On The Enhanced Solubility Of Low Rank Coal By Low Temperature Plasma

Coal resources is a major energy resource in China.From the point that the current production and supply ability of energy and energy consumption composition in China,the reality that coal is the most important first nature resource will not waver in substantial amount of time in our country.But coal industry of China is confronting with a lot of problems and recurring illness now,such as market slump、severe overcapacity、low comprehensive utilization rate and critical environmental pollution etc.Therefore,there is a extreme significance energy strategy to China that researching the clean efficiency of coal.Processing method is a kind of effective means to advance the utilization value of low rank coal and expand the utilization space of low rank coal.In view of the special chemical reactivity of the plasma,the physical reactions and chemical reactions are completed which be difficult to occur at normal temperature and pressure,this paper aims at improving the solubility of coal by plasma technology.The basic idea is to employ the dielectric barrier discharge plasma treatment for coal samples,observing effect of solvent treatment,treatment atmosphere(nitrogen,air)、input voltage、processing times、single processing time on the solubility of coal,using solvent extraction rate as the evaluation standard of discharge effect.The changes of coal and solvent extracts were analyzed through several testing methods of elemental analysis,industrial analysis,infrared spectroscopy and GC/MS.After plasma treatment,there are some changes on the contents of chemical elements,main functional groups,solvent extraction components and contents.As for nitrogen DBD treatment,the solvent extraction rate of coal sample Ⅰ,Ⅱ,Ⅲ and IV are respectively increased by 3.826%,5.24%,1.62%,and 3.036%under different working conditions.For the air DBD treatment,the solvent extraction rate of coal sample Ⅱ and sample d are respectively increased by 3.93%,3.26%under different working conditions,The experimental results show that it is feasible to enhance the solubility of coal by plasma.According to the experimental phenomena and results,combined with the knowledge of coal structure,plasma and the existing research results,we discuss the mechanism of the change of physical and chemical properties of coal.The main structure of the coal is a three-dimensional space polymer,the structural unit is connected by various bridge keys.Scholar Wahrman proposed:small molecules which rely on a variety of binding force adsorbed on coal molecules is regularly distributing in the porous of the coal molecules.Therefore,this topic uses the dielectric barrier discharge plasma is used to excite working gas to produce active particles,active particles transfer the energy to the coal sample by collision and produce the thermal effect,weaking these bonds or break the chemical bonds to form new molecules.In the process of discharge,the electric field,the free radicals generated and the thermal energy produced by the collision can remove the moisture in the coal,and the solvent treatment can accelerate the reaction.