CFD Modelling and Simulation of a VOC Removal Silo

Abstract

The removal of volatile organic compounds (VOC) is an environmentally challenging problem. The organic compounds are widely used in automotive, plastic, and other industries. The systems containing VOC are multiphase by nature, often with solid, liquid, and gas phases.The different devices and processes can be used for the separation task, for example, scrubbing. However, the simplest way to treat a system with VOC is a counter current gas contact, where the flowing gas purifies the product. This operation can be completed in columns, where the solid particles are discharging, and the gas is fed at the bottom of the column to ensure the proper phase contact and residence time.In our previous work, the modelling and optimisation of a laboratory scale silo were performed [1]. After the mesh independence study, the measured residence times were compared to the simulated ones, and a validated model was created. Then we optimized the inner construction of the vessel by placing inserts serves the optimal discharge (mass flow) of the silo.In this study, we extend the capabilities of the model by the inclusion of the counter-current gas stream. Multiscale and multidimensional models are implemented to calculate the interparticle removal and surface reactions. The model with different spatial dimensions was compared to each other by the mean of information transfer, and content as well. The modelling approaches are compared to each other based for further use. In the case of pseudo-2D devices, where the changes in one of the spatial dimensions is neglectable there is no need to implement 3D simulations, it is enough to create a proper 2D model.