Two-phase Flow Modelling and Simulation of Gas Purification Column

In the technologies where harmful organic solvents are used it is necessary to purify the waste gases in order to ensure the protection of environment and the fulfillment of environment protecting laws. A wide-spread solution is to adsorb the undesired components on a porous fixed bed but it saturates during the operation and should be regularly regenerated resulting in an economic loss. One of the solutions to improve the process is the use of a moving bed equipment, where the regenerated particles are continuously fed to the adsorber and the saturated particles are transferred toward the regenerator providing this way a continuous operation. The objective of our research is to model and simulate the gas-solid two-phase flow using the immersed boundary method and calculate the particle movement and the adsorption process for the individual adsorber particles applying the principles of discrete element method. The surface of particles is discretized and the component transport to the surface element and the degree of saturation of surface element is calculated by a first-order adsorption kinetics. The calculation method is demonstrated on a single particle. The two-dimensional compressible Euler equations are discretized and solved by the second-order accurate TVD-MacCormack method to effectively handle the oscillations arising in the vicinity of steep spatial fronts. Furthermore, considering the physical bases of compressible gas flow, we used non-reflecting numerical boundary condition at the outflow boundary of calculation domain.