{"title":"A model for hindered diffusion in pores","authors":"","doi":"10.1016/j.cherd.2024.08.010","DOIUrl":null,"url":null,"abstract":"<div><p>Hindered diffusion is a longstanding interest to chemical engineers working in such fields as heterogeneous catalysis, adsorptive and biochemical separations, and environmental engineering. In this work, a novel and universal model unifying the pore diffusion and surface diffusion was deduced theoretically to account for the pore diffusion control or surface diffusion control in pores. Based on the model, a versatile restrictive factor expression was proposed to describe the correlation between the effective diffusivity and the ratio of molecular diameter to pore diameter. Various variations of restrictive factor versus the ratio of molecular diameter to pore diameter from reported literatures were interpreted better than previous restrictive factor equations. Especially, the restrictive factor with non-monotonic variations could not be explained with the reported restrictive factor equations, but interpreted well by equation in this work. Furthermore, the diffusion tortuosity was first proposed herein to account for the effect of molecule diffusion path on diffusion behavior in pores.</p></div>","PeriodicalId":10019,"journal":{"name":"Chemical Engineering Research & Design","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Research & Design","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0263876224004842","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Hindered diffusion is a longstanding interest to chemical engineers working in such fields as heterogeneous catalysis, adsorptive and biochemical separations, and environmental engineering. In this work, a novel and universal model unifying the pore diffusion and surface diffusion was deduced theoretically to account for the pore diffusion control or surface diffusion control in pores. Based on the model, a versatile restrictive factor expression was proposed to describe the correlation between the effective diffusivity and the ratio of molecular diameter to pore diameter. Various variations of restrictive factor versus the ratio of molecular diameter to pore diameter from reported literatures were interpreted better than previous restrictive factor equations. Especially, the restrictive factor with non-monotonic variations could not be explained with the reported restrictive factor equations, but interpreted well by equation in this work. Furthermore, the diffusion tortuosity was first proposed herein to account for the effect of molecule diffusion path on diffusion behavior in pores.
期刊介绍:
ChERD aims to be the principal international journal for publication of high quality, original papers in chemical engineering.
Papers showing how research results can be used in chemical engineering design, and accounts of experimental or theoretical research work bringing new perspectives to established principles, highlighting unsolved problems or indicating directions for future research, are particularly welcome. Contributions that deal with new developments in plant or processes and that can be given quantitative expression are encouraged. The journal is especially interested in papers that extend the boundaries of traditional chemical engineering.