煤焦催化气化的修正随机孔模型研究

针对煤焦催化气化中传统的动力学模型不再适用这一情况，以广泛应用于煤焦气化动力学研究的随机孔模型为基础，考虑了催化剂对反应过程的催化作用，通过引入催化作用因子，建立了适用于煤焦催化气化反应的修正随机孔模型．选取神府煤焦为研究对象，将煤焦CO2催化气化作为探针反应，做了典型KCl催化荆和K-Ni复合催化剂的催化气化实验，并对模型进行了验证．结果表明：修正随机孔模型较好地体现了煤焦催化气化的动力学规律，即催化剂的添加有效地增大了反应界面处的活性部位和活性表面积，使气化反应在更温和的条件下快速进行．经验常数说明Ni-K复合催化剂的催化能力大于KCl催化剂，这与许多学者的研究结果是一致的．另外，由于反应初期的传质阻力不可忽略，故实验值与模拟值存在一定误差．

Study on Modified Random Pore Model of Catalytic Coal Char Gasification

Based on the widely used gas-solid random pore model,a modified random pore model was developed to describe the catalytic coal char gasification more properly.A function with the catalytic efficient factor was applied to indicate the influence of the catalyst on the reaction.The model was validated with the experimental results of CO_2 catalytic gasification of Shenfu coal char.The kinetic behaviour and catalytic mechanism are well explained by the modified random pore model.It is revealed that catalysts enable to effectively improve gasification rate and reduce gasification temperature by the increasing active surface area and sites.The experiential constant shows the higher catalytic effect of K-Ni binary catalyst than KCl to agree with the other scholars' experimental results.A slight disagreement between the simulated and the experimental results can be found due to the mass transfer resistance during the initial reaction periods.