CFD-based modeling of precipitation by supercritical anti-solvent process of microparticles from grape pomace extract with population balance approach

The production of nano and microparticles by means of a supercritical process is a highly promising technique that is commonly applied in the pharmaceutical industry. Even though the industrial application of the technique is not a novelty, understanding the associated physics is still a subject under study. Experimental data and mathematical modeling allied to computational simulation are the principal tools used to manage the knowledge needed to enhance the process yield and obtain a product with the required quality and appropriate physical properties. Therefore, in this study a mathematical model was applied to describe the formation of particles of a grape pomace extract using the supercritical anti-solvent (SAS) process. The model was coupled with a population balance approach applied to determine the precipitation kinetics, and the particle size distribution of the grape pomace extract was experimentally obtained. The model considers steady-state non-isothermal turbulent flow under supercritical conditions, while Peng-Robinson's Equation of State and Van der Waals mixing rule were the thermodynamic models used. The mathematical model was numerically solved by CFD techniques, and the precipitation kinetics was successfully represented by comparing numerical and experimental data. Also, it was possible to capture the effects of parameters, such as the mass flux ratio between the solute and anti-solvent, as well as the solute concentration, on the particle nucleation and grow the rates underall experimental conditions studied. In general, the numerical predictions are in good agreement with the experimental data and effects on the nucleation and growth rates were confirmed.