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2.3 MECHANICAL ENGINEERING
Upflow anaerobic sludge blanket (UASB) reactors stand out as a feasible option for treating wastewaters while generating a valuable amount of biogas. It is known that the efficiency of UASB reactors is closely linked to its hydrodynamics. Therefore, understanding the role of each phase (solids, liquid and gas) in the mixing conditions inside the reactor and having validated numerical models for predicting the flow behavior has become fundamental for the design and optimization of UASB reactors. In this context this work aims to develop and validate a three phase Computational Fluid Dynamics (CFD) model of an UASB reactor. Eulerian-Eulerian laminar three-dimensional multiphase simulations were carried out using Fluent 16.2. The model was validated using Particle Image Velocimetry (PIV) experiments. The reactor was divided into four regions, according to its mixing conditions. Validation results showed differences between experimental and computational results for the liquid velocity to be less than 4%. Dead zones accounted for 0.02% of the total volume of the reactor. From the simulation results, a sludge wash out of 179 mg·L−1 was found. The validated model can be further used for optimization studies for this type of wastewater treatment bioreactor.
Camila D’Bastiani, Jéferson Luis Alba, Gabriel Tomazzoni Mazzarotto, Severino Rodrigues de Farias Neto, Lademir Luiz Beal, Anthony Reynolds, and David Kennedy , "Multiphase CFD modelling and PIV validation of a UASB reactor", AIP Conference Proceedings 2116, 030007 (2019), DOI: 10.1063/1.5113991
PETROBRAS; TU Dublin