R.J. Van Velden, S. Woudberg, E. Dumont, H. Fidder, J.Th.M. De Hosson
{"title":"The effect of particle surface roughness and biofilm accumulation on the pressure drop over a biofilter","authors":"R.J. Van Velden, S. Woudberg, E. Dumont, H. Fidder, J.Th.M. De Hosson","doi":"10.1016/j.ces.2025.122185","DOIUrl":null,"url":null,"abstract":"In this study, the pressure drop prediction of the existing granular rectangular Representative Unit Cell (RUC) model, which already accounts for biofilm development and sphericity, is adapted to include particle surface roughness. The novelty of this study is that a surface roughness factor is derived based on physical principles. It was found to be a function of the average height and number of roughness elements, the porosity as well as the particle diameter. This factor is included in both the Darcy and inertial Reynolds number flow terms. The proposed model includes no empirical coefficients and is validated against experimental data for a biofilter, operated over 107 days, with expanded schist as packing material. It was found that a decrease in average particle shape factor produced an increase in surface roughness over time. The average shape factor was also introduced in order to increase the interstitial form drag coefficient. The average surface roughness of the packing material was measured with a confocal microscope, by utilizing white light microscopy, and the value was used in the pressure gradient prediction of the RUC model. The proposed model is compared to a modified Ergun equation, adjusted to be applicable to biofilters, and satisfactory results are obtained. A sensitivity analysis is also performed on the average height of surface roughness elements, particle diameter, and average particle shape factor. The proposed model is an improvement on the existing models from the literature considered in this study.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"29 1","pages":""},"PeriodicalIF":4.1000,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Engineering Science","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.ces.2025.122185","RegionNum":2,"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
In this study, the pressure drop prediction of the existing granular rectangular Representative Unit Cell (RUC) model, which already accounts for biofilm development and sphericity, is adapted to include particle surface roughness. The novelty of this study is that a surface roughness factor is derived based on physical principles. It was found to be a function of the average height and number of roughness elements, the porosity as well as the particle diameter. This factor is included in both the Darcy and inertial Reynolds number flow terms. The proposed model includes no empirical coefficients and is validated against experimental data for a biofilter, operated over 107 days, with expanded schist as packing material. It was found that a decrease in average particle shape factor produced an increase in surface roughness over time. The average shape factor was also introduced in order to increase the interstitial form drag coefficient. The average surface roughness of the packing material was measured with a confocal microscope, by utilizing white light microscopy, and the value was used in the pressure gradient prediction of the RUC model. The proposed model is compared to a modified Ergun equation, adjusted to be applicable to biofilters, and satisfactory results are obtained. A sensitivity analysis is also performed on the average height of surface roughness elements, particle diameter, and average particle shape factor. The proposed model is an improvement on the existing models from the literature considered in this study.
期刊介绍:
Chemical engineering enables the transformation of natural resources and energy into useful products for society. It draws on and applies natural sciences, mathematics and economics, and has developed fundamental engineering science that underpins the discipline.
Chemical Engineering Science (CES) has been publishing papers on the fundamentals of chemical engineering since 1951. CES is the platform where the most significant advances in the discipline have ever since been published. Chemical Engineering Science has accompanied and sustained chemical engineering through its development into the vibrant and broad scientific discipline it is today.