甲醇合成催化剂内扩散效率因子三种模型数值解的比较 Ⅰ.未中毒催化剂内扩散效率因子

COMPARISON OF NUMERICAL SOLUTIONS OF THREE KINDS OF DIFFUSION MODELS FOR THE EFFECTIVENESS FACTOR OF METHANOL SYNTHESIS CATALYSTⅠ.EFFECTIVENESS FACTOR FOR UNPOISONED CATALYST

对加压甲醇合成复合反应内扩散效率因子分别建立了一维多组分扩散模型、一维简化多组分扩散模型和一维关键组分扩散模型。用正交配置法求取数值解,并分别与对应的实验值比较,对各个模型的误差进行分析,提出了不同计算目的的适用模型。

For the multiple reaction system of methanol synthesis,a multi-component diffusion model,a simplified multi-component diffusion model and a key-component diffu- sion model have been set up.The numerical solutions of the effectiveness factor for each model have been obtained by orthogonal collocation method and compared with experimental values under similar conditions.Form the concentration profiles in a catalyst pellet calculated by these one dimentional models,it was found that the deviations of the concentration pro- files from each other for key-components are little.But the deviations for the other compo- nents are large. In theory the multi-component diffusion model describes precisely the diffusion and re- action processes in a multi-component system.But the time for obtaining numerical solu- tions is long.As the difference between effectiveness factors calculated from the multi-com- ponent diffusion model and from the simplified multi-component diffusion model is less and the time required for calculating by the simplified multi-component diffusion model is not very long,the simplified multi-component diffusion model is recommanded for calculating effectiveness factors of Cu-based catalyst in methanol synthesis reaction.