煤焦水蒸气气化动力学模型及参数敏感性研究

在热重分析仪上对小龙潭煤焦、府谷煤焦和晋城煤焦水蒸气气化过程进行了研究。使用收缩核模型、混合模型和随机孔模型模拟了三种煤焦水蒸气气化反应过程。结果表明,混合模型总体上模拟效果最好,收缩核模型和随机孔模型对低变质程度的小龙潭煤焦气化过程模拟效果不佳,但是适用于模拟另外两种煤阶较高的煤焦气化过程。求解了三种模型的动力学参数,并分析了不同模型参数出现差异的原因。同时,采用敏感性分析法定量研究了模型中的参数发生偏差时引起模型误差的大小,并通过比较发现反应速率常数k为敏感性因素,而混合模型中反应级数n和随机孔模型中孔结构参数ψ为非敏感性因素。

Kinetic models of coal char steam gasification and sensitivity analysis of the parameters

The steam gasification of XLT, FG and JC coal chars was studied by isothermal thermogravimetric analysis. The relationship between reaction rate and carbon conversion of three coal chars was simulated by shrinking core model(SCM), traditional model(TM) and random pore model(RPM). The results show that TM is the best one overall for three coals. SCM and RPM are not suitable to describe the gasification process of low-rank XLT coal char, though they have satisfied simulation results to the other two coal chars with higher coal rank. The kinetic parameters were calculated by three models, and the reason for their differences was analyzed. Based on the sensitivity analysis method, the error of the prediction with the change of parameters was studied. It is shown that the apparent reaction rate k is a sensitive parameter, and the reaction order n in the TM and the structural parameter ψ in the RPM are less sensitive parameters.