压力与活性碱及碱土金属对准东煤热解特性及热解动力学的影响

Kinetics andproperties analysis of Zhundong Coal pressurized pyrolysis

采用高温高压热重分析仪研究了准东原煤(R-form)和酸洗煤(H-form)样品在不同压力下的热解失重特性,采用分布活化能模型法对它们的热解动力学参数求解。结果表明:准东煤在热解过程中依然保留了丰富的孔隙结构,H-form煤比R-form煤的孔隙更加丰富,且H-form煤具有更高的热解反应性,但R-form煤和H-form煤1000℃的热解焦随着压力的变化没有明显区别;压力增加可明显影响准东煤的热解过程,当热解压力小于0.4 MPa时,压力升高可以促进挥发分的释放,但当压力超过0.4 MPa时,压力升高对挥发分的释放起抑制作用;当热解压力低于1 MPa时,准东H-form煤活化能要高于准东R-form煤,准东R-form煤与H-form煤两者活化能变化过程与四个主要热解阶段相一致。

The pyrolysis process of raw(R-form)and acid-washed(H-form)Zhundong coal was investigated by high temperature pressurized thermogravimetric analyzer(PTGA)and the kinetic parameters were calculated using distributed activation energy model(DAEM).The results show that the pore structures of Zhundong coal keep abundant in pyrolysis.The pore structures of H-form coal are more abundant than that of R-form coal.There is no obvious difference on R-form and H-form char obtained at 1000℃.Pressure has great influence on the behavior of Zhundong coal pyrolysis.The enhance of pressure(<0.4 MPa)is beneficial for volatile releasing,however,after that,it suppresses volatile releasing.The activation energy(E)of H-form coal is much higher than that of R-form coal when the pyrolysis pressure is less than 1 MPa.The activation energy change process of R-form and H-form coal is consistent with the four main pyrolysis stage.