煤中氮在热解过程中释放规律的数学模拟

以化学渗透模型(CPD)为基础构建煤的结构，以实验数据为基础，通过对煤中氮在热解阶段反应历程的描述，以及对NOx的主要前驱体HCN和NH3生成的动力学表达，建立了煤热解阶段氮释放的模型，将模型的计算结果与五种煤在管式固定床反应器中热解阶段形成HCN和NHx的测定结果进行比较，研究发现：模型能够相对准确的预测HCN形成(误差在20％以内)，但由于没有考虑惰质组的影响，对部分煤NHx的模拟误差较大(甚至超过50％)，模型也表达出在快速热解条件下随温度升高，HCN和NHx的生成量增加；随煤阶增加，HCN生成量减少；随惰质组含量增加，NHx的生成量增加的释放规律。

MATHEMATIC SIMULATION OF NITROGEN RELEASE RULE DURING COAL PYROLYSIS

Due to the complexity of nitrogen released reaction in coal and the lack of effective experimental methods,there is less sound understanding for the formation and release of precursors of NO_ x ,which are HCN and NH_3,during coal pyrolysis.In this paper,a mathematic model that describes the reaction route of nitrogen and predicts the formation of HCN and NH_3 by kinetics during coal pyrolysis has been developed based on the CPD model.Comparison of simulation of HCN and NH_3 values with experimental data from pyrolysis experiments of five coals in the tubular fixed-bed reactor indicates the model can correctly predict the formation HCN,which a relatively big error of NH_3 formation is made because of less considering the effect of the inertinite in coal.Moreover,the model gives a rule of nitrogen release during fast pyrolysis:the yield of HCN and NH_3 increases with an increase of temperature,but the yield of HCN decreases with the increase of coal rank that has a strong relation with the amount of volatiles in coal,the inertinite-rich coal tends to release more NH_3 that is strongly subjeted to the properties of coal char.