Mass transfer towards a reactive particle in a fluid flow: Numerical simulations and modeling. (18th May 2019)

• Record Type: Journal Article
• Authors: Sulaiman, Mostafa; Climent, Eric; Hammouti, Abdelkader; Wachs, Anthony
• Is Part Of: Chemical engineering science. Volume 197(2019)
• Page Start: 496
• Page End: 507
• Publication Date: 2019-05-18
• Subjects: Catalyst particle -- Mass transfer -- Sherwood number -- Chemical reaction -- Thiele modulus; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2018.12.051
• Languages: English
• ISSNs: 0009-2509

Abstract

Graphical abstract: Highlights: Model for the mass transfer coefficient accounting for diffusion and internal first-order chemical reaction. Direct numerical simulations (DNS). Wide range of Reynolds and Schmidt numbers and Thiele modulus. Reactive Sherwood number. Abstract: We study mass transfer towards a solid spherical catalyst particle experiencing a first order irreversible reaction coupled to an external laminar flow. Internal chemical reaction and convective-diffusive mass transfer in the surrounding fluid flow are coupled by concentration and flux boundary conditions at the particle surface. Through this coupling, the mean particle surface and volume concentrations are predicted and the internal/external Sherwood numbers are obtained. We investigate the interplay between convection, diffusion, and reaction by computational fluid dynamics and establish a model for the mass transfer coefficient accounting for diffusion and internal first-order chemical reaction. We obtain a prediction of the mass transfer coefficient through mass balance or using the classical additivity rule. The model is numerically validated by fully resolved numerical simulations over a wide range of Reynolds number, Schmidt number and Thiele modulus which shows that assuming decoupled treatment of external and internal mass transfer gives very accurate predictions. Finally, we test the unsteady response of the model. The model predicts the evolution of the mean volume concentration for a particle placed in a steady convective-diffusive stream. Predictions of the unsteady model are in very good agreement with computed results.