Continuous stirred tank coalescence/redispersion reactor: A simulation study

This paper presents an analysis and detailed numerical study of the continuous stirred tank coalescence/redispersion reactor (CSTCRR), developed as a multidimensional population balance model combining a well-stirred reactor with the generalized coalescence/redispersion (gCR) model of micromixing. The gCR micromixing model is based on the concept of interactive population of fluid elements, identified as Kolmogorov microscale eddies under the given turbulence conditions, and represents mixing of chemical species on microscale by collision induced mass exchange processes. This model allows modelling diverse micromixing rates for different chemical species depending on their molecular diffusion properties. An infinite order multivariate moment equation model was elaborated by applying the joint moments of concentrations of chemical species from which a second order moment equation reduction was obtained by means of the cumulant-neglect closure method. The simulation results obtained by the second order moment equation model for the irreversible quasi-linear bimolecular and quadratic autocatalytic with linear decay reactions, and for the Van de Vusse reaction network revealed that the CSTCRR spans the whole range of variation of the micromixing intensity between the two micromixing extremes, i.e. perfect mixing and complete segregation, and it produces a smooth monotone sequence of product yields in the mixing space as the micromixing intensity is varied between these two extremes by modulating the rate determining parameters.