干燥提质对褐煤表面结构的影响

Drying Upgrading Affected to Surface Structure of Lignite

文章介绍了在回转干燥器中,以气体热载体内热式干燥工艺对褐煤进行干燥,分别利用化学分析法、FTIR法、BET法,分析了煤样中含氧官能团含量随干燥温度的变化;不同干燥煤样的比表面积和孔容积变化;明确了气体热载体内热式干燥工艺对褐煤表面结构的影响。实验结果表明,煤样中含氧官能团含量随干燥温度的升高而降低,在280℃之前主要脱除羧基,280℃之后主要脱除酚羟基;在温度低于330℃时,孔容积和比表面积随温度升高逐渐减小,380℃时显著增大。

The paper introduced the lignite dried with a thermal drying technique within a gas thermal carrier in a rotary dryer.The chemical analysis method,FTIR method and BET method were applied to analyze the content of the oxygen-containing functional groups with the variation of the drying temperature,to analyze the variation of the special surface area and the porous volume of different dried coal sample and to confirm the thermal drying technique within gas thermal carrier affected to the surface structure of the lignite.The experiment results showed that the content of the oxygen-containing functional groups in the coal sample would be decreased with the drying temperature increased.Before the temperature of 280℃ reached,carboxyl would be removed mainly and after the temperature of 280℃ reached,phenol carboxyl would be removed mainly.When the temperature was below 330℃,the porous volume and special surface area would be steadily decreased with the temperature increased.When the temperature reached at 380℃,the porous volume and special surface area would be decreased obviously.