The Effect Of Inherent Minerals On The Thermal Evolution Of The Structure And The CO₂ Gasification Performance Of Shengli Lignite

The gasification reaction of raw coal chars?SL-Raw,SL-300 J,SL-400 J,SL-500 J,SL-600 J,SL-700 J,SL-800J?and the demineralized coal chars?SL+,SL+-300 J,SL+-400 J,SL+-500 J,SL+-600 J,SL+-700J?with CO₂ was performed in a fixed-bed reactor.The structure of coal chars analyzed by FT-IR,XRD and Raman.The results were showed as follows:The methyl,methylene,oxygen-containing functional groups and aliphatic side chains of coal chars were destroyed,and the average diameter and average stacking height of coal crystallites were increased,and the spatial arrangement became ordering with the heat treatment temperature enhanced.The organic carbon converted into carbon microcrystalline structure of the main structure of coal chars at 700°C.The main structure of coal chars,which was initial aliphatic chain aromatic polymer became fused ring aromatic polymer by polycondensation with the average number of condensed aromatic rings increasing through the breakage of chemical bonds,and then became carbon microcrystalline structure as the temperature increases in the process of structure evolution through heat treatment.The inherent minerals in Shengli lignite had significant effects on structure change.The hydrochloride can't remove the aluminosilicate components,but it can effectively remove the Ca²⁺?Na+ which replaced by H+,which resulting in C-OM(M represent Ca²⁺?Na+)converted into C-OH,and the functional groups of coal chars had changed.The inherent minerals played an important role on the gasification performance of coal char with CO₂.The minerals existing in coal chars obviously inhibited transition,which the organic carbon became carbon microcrystalline structure,and char reactivity was better.The catalysis of inherent minerals weakened when carbon microcrystal structure participated in the gasification reaction of coal char with CO₂.