煤质活性炭氧化自燃热失重及传热特性研究
Study on Thermal Loss and Heat Transfer Characteristics of Oxidized Spontaneous Combustion of Coal-based Activated Carbon
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摘要: 为了对煤质活性炭氧化过程中传热特性及热失重变化进行探究,采集生产工艺过程中的3种煤质活性炭:压块料、炭化料及活化料,利用激光导热仪及热重-差热同步热分析仪对样品氧化反应过程中的热物性及热失重参数进行测定,结合非线性氧化热动力学方法、计算得出各样品表观活化能。结果表明:活化料及炭化料总放热量、最大热释放率均大于压块料,热物性参数表现出明显的阶段特征,样品热物性参数对温度敏感性排序依次为比热容>热扩散系数>导热系数;活化料及炭化料表观活化能小于压块料,经过炭化及活化工序,炭化料和活化料氧化自燃倾向性增大。Abstract: To research the heat transfer characteristics and thermogravimetric change of coal-based activated carbon during oxidation, and collected three kinds of coals in the production process of coal-activated carbon: briquette, carbonized materials, activate material. Laser thermal conductivity meter and thermogravimetric-differential thermal simultaneous thermal analyzer were used to measure the thermophysical properties and thermal weight loss parameters in the sample oxidation process, combined with the nonlinear oxidation thermodynamic method, and the apparent activation energy is calculated. The results demonstrated that the total heat release and maximum heat release rate of the activated material and the carbonized material are greater than briquette material. Thermal physical parameters show obvious stage characteristics. The order of thermophysical parameters to temperature sensitivity of the sample is: specific heat capacity > thermal diffusion coefficient > thermal conductivity; the apparent activation energy of activated materials and carbonized materials is less than that of pressed materials, the oxidized spontaneous combustion tendency increases after carbonization and activation process.