CFD-Driven Optimization of PVC Flocculation and Sedimentation in Industrial Thickener Tank. Enhancing Process Performance and Reducing Environmental Impact Master’s thesis in Sustainable Energy

Abstract

The aim of the thesis was to optimize the flocculation process of PVC-particles in a thickener tank to increase the separation of microplastics from the industrial drain. This was set to be solved by both testing different flocculation concentrations on-site and by simulating the flow dynamics in ANSYS Fluent. A base model of the tank was developed by calibrating CFD data to match laboratory results. This calibrated model was later used to evaluate the effects of flocculant dosage, PVC inlet concentration and PVC particle size on separation performance. Ultimately, it became clear that particle size was the most critical factor. Fine particles (0.5-1 μm) significantly reduced separation efficiency compared to coarser PVC types (50–250 μm). Additionally, the study identified an optimal PVC inlet concentration (200 mg/L) and flocculant dosage (100 L/h) that minimizes both PVC and flocculant waste.