Influence on Porosity of Cu - Based Catalyst to the Effective Diffusion Coefficients

The influence of porosity of 18 kinds of Cu - based catalysts of methanol synthesis on the effective diffusion coefficients is studied. The catalysts have the different parameters of pore structure. The catalyst pore is divided into micro- pores of larger than10nm and less than 10nm. The study indicates that,the tortuosity factors increases while the porosity of micro pore increases which means the increase of the diffusion resistance. An empirical equation expressing the relationship between porosity and tortuosity is then obtained which can be used to estimate tortuosity in commercial practice.