节能型变换催化剂曲折因子和气体有效扩散

设计自制改进的Wicke-Kallenbach扩散池,按稳态法实验测定了常压313K下N2-CO,N2-CO2,CO-CO2二组分气体和CO+CO2-N2,CO+N2-CO2,N2+CO2-CO三组分气体在还原态LB型节能高温变换催化剂内的逆流扩散通量,实验所得二组分和三组分气体扩散通量之比符合Graham气体扩散规律,表明扩散池设计合理,测定过程稳定、数据可靠。同时说明气体在还原态LB型节能高温变换催化剂内的扩散是过渡区扩散。根据平行交联孔模型,计算出以平均孔半径为基准的曲折因子和以孔分布为基准的曲折因子以及各气体的有效扩散系数。

Tortuosity factors of energy-saving shift catalyst and effective diffusivity of gases

The binary and ternary counter-current diffusion fluxes of different gas-pairs (N2-CO,N2-CO2,CO-CO2,and CO+CO2-N2,CO+N2-CO2,N2+CO2-CO) through reduced LB energy-saving high temperature shift catalyst were measured at 313 K and ambient pressure by the steady-state method. The tests were performed in a domestic-made modified Wicke-Kallenbach (MWK) diffusion cell. The molar ratio of diffusion fluxes of binary and ternary gases is accorded with Graham's law,which shows that the MWK diffusion cell is in a reasonable design with a steady measuring procedure and reliable data,and the diffusion in LB catalyst is in transition region. Based on the cross-linked pore model,the tortuosity factors of reduced LB catalyst were calculated on the basis of mean transport-pore diameters and pore size distribution respectively,which differed from each other. The effective diffusivities of gases in different gas-pairs were calculated.