Fluid flow simulations verified by measurements to investigate adsorption processes in a static mixer. (1st December 2018) - Maier, Marie-Luise
Abstract: Protein purification is a complex task as the target proteins have to be isolated from the byproducts. One way to extract the proteins (referred to as adsorptive) is to combine adsorption processes and a high-gradient magnetic separation. This mechanism involves the adsorption of the adsorptive onto the functionalized surface of a magnetic particle and its subsequent separation by magnetic forces. To get insight into the adsorption processes by simulation, appropriate investigations are performed. In this work, the three-component flow (water, adsorptive, particles) is described by a novel Euler–Euler–Lagrange approach that considers adsorption processes on the moving particles suspended in water. As the adsorption is influenced by the water flow and the fluid mixing, the simulations are conducted in a static mixer and verified by measurements. The feasibility of the adsorption approach is shown. The water flow is modeled by the Navier–Stokes equations, and the adsorptive by the advection–diffusion–reaction equation. The particles are assumed to be point particles and are described with a discrete particle method based on Newton's equation of motion. The fluids are computed using a lattice Boltzmann method. In case of the adsorptive, the formulation of the sink term is introduced to consider the adsorption. The simulation of the water flow is verified by magnetic resonance imaging measurements of the velocity, and the results show very good accordance. To justify the fluid mixing simulation, a real experiment with water and an ink solution is conducted. Both show a similar concentration profile in the mixer. The feasibility of the approach considering the adsorption processes on in water suspended particles is presented.