Study On The Upgrading Process Of Lignite Of Shengli And Lignite Semicoke Reactivity

Lignite abundantly reserves in Inner Mongolia. However, because of its high watercontent and high oxygen content which reduces their efficiency and increases the cost, sothe key to efficiently use lignite is to master the handling methods and its basiccharacteristics. This present paper aims to make researches on the behavior change andheat reactivity of lignite of Shengli in xilingol league during the pyrolysis upgradingprocess.The lignite of Shengli is proceeded pyrolysis upgrading test on the fixed bed, wemainly inspecte the effects of upgrading final temperature on the distribution of products.Making basic analysis for the semicoke gaining after upgrading tested with the ways ofproximate annalysis, elemental analysis and calorific value analysis. Obtaining thestructural changes in the physical and chemical conditions of semicoke at differentupgrading temperature by the methods of SEM、XRD、FTIR. The results indicate thatdifferent functional groups decompose in the upgrading process, and accompany with CO2,CO、CH4、H2escaping. With the temperature increasing, oxyegn content in semicokedecreases sharply, semicoke shrinks, further, the structure turnes to be typical graphite,aliphatic hydrogen and functional group containes oxygen reduced.By Thermogravimetric Analysis to make pyrolysis characteristic testing, and thenanalyzing the pyrolysis kinetics property of lignite through different methods, we manageto estimate the pyrolysis kinetics parameters. The results shows that there are two stages,that is, low and high temperature districts during pyrolysis process, we calculate itskinetics parameters respectively. With heating rate increasing, activation energy reduces atlow temperature district, and rises at high temperature district. The changes of activationenergy in the whole pyrolysis process are described by using equal percent conversionmethod, with the conversion rate increasing, the activation energy decreases at first andthen increases.By thermogravimetric Analysis, we get the data of the heat reactivity of semicokeand examine the influences of upgrading final temperature, atmosphere (CO2、O2), graindiameter, maceral on the heat reactivity. The reaction process is described by the shrinkingcore reaction model and we estimate kinetics parameters. The results present that temperature increases with the upgrading, CO2reactivity and O2activation energyenhances gradually.