Experimental Study On The Influence Of Char Pore Structure On Char Nitrogen Release Characteristics

China’s consumption of coal is more than half the world’s total consumption.China’s most important primary energy is coal, this energy structure will not change inthe short term. Coal produce large amounts of pollutants NOx in the combustion process,causing serious environmental problems. In response to coal-fired power plant NOxemissions requirements, changes in the pore structure of the final char char nitrogen toNO conversion impact study for this article.This paper selects three of coal (Linfen coal, steam coal, Zhangjiakou Coal) in ahorizontal tube furnace under an inert atmosphere were preparing temperature (900℃,1100℃) pyrolysis char and CO2atmosphere under preparation temperature (700℃,900℃,1100℃) the gasification of char. At the same time, physical properties ofparent coal or coal char samples such asKinetic analysis and pore structure analysishave been studied.Coal combustion reaction between primary and zero-order reaction,the rank of coal have effect on the reaction rate.Char combustion reactions have greaterintrinsic activation energy in a chemical reaction control area, the rate of diffusion of thegas diffusion zone limits the reaction rate. With the char combustion reaction, thespecific surface area decreases after the first increase, the smaller The intrinsic reactionrate of char the better surface area gain. Gasification char have more developed porestructure than pyrolysis char,with gasification temperatureincreasesof gasification charsignificantly increases the specific surface area, but small difference between thepyrolysis char.the Developed extent of pore structure affect the effective diffusioncoefficient of oxygen in the char surface,while smaller effect of temperature on theeffective diffusion coefficient.Lower intrinsic reactivity, more developed pore structure,then the diffusion reaction zone temperature control zones to move high temperature.At the same temperature, char-NO reduction reaction rate constants and charcombustion reaction rate constants are similar,mainly affecting the combustion reactionin the reaction rate in two concentration of gas,char burning rate substantially higherthan the char-NO reduction the reaction rate two orders of magnitude.Isothermalcombustion test, combined with the efficiency factor and specific surface area of theeffective surface area,the effective surface area increases with the reaction after the firstreduction.Consistent with the specific surface area, effective factors combustionreaction after the first decreased and then increased,char-NO reduction reactionefficiency factor remained1.Before0.1oxidation rate of the char N in carbonconversion rate determined by the amount of char nitrogen itself,as the reaction further,to maximize the effective surface area.The rapid increase in the speed of the oxidizedchar N,since the effective surface area promote the reaction rate increase.On the otherhand, by the oxidation reaction of carbon suppress competition, the oxygen concentration began to decline.NO released from char,the higher the concentration ofthe char surface, thereby combining the reduction reaction with carbon char surfaceactive point,making the NO conversion rate remains slow growth.Char combustioneffective surface area of the early effects of NO production is weak, but the total surfacearea of phase reduction of NO obvious.Attempts to increase the specific surface areacan improve the reductionreaction of char-NO and reduce the NO conversion rate.