Percy Kampeis

Optimization of High Gradient Magnetic Separation Filter Units for the Purification of Fermentation Products

High gradient magnetic separation (HGMS) has been established since the early 1970s. A more recent application of these systems is the use in bioprocesses. To integrate the HGMS in a fermentation process, it is necessary to optimize the separation matrix with regard to the magnetic separation characteristics and permeability of the non-magnetizable components of the fermentation broth. As part of the work presented here, a combined fluidic and magnetic force finite element model simulation was created using the software COMSOL Multiphysics and compared with separation experiments. Finally, as optimal lattice orientation of the separation matrix, a transversal rhombohedral arrangement was defined. The high suitability of the new filter matrix has been verified by separation experiments.

Optimizing a rotor-stator filter matrix for high-gradient magnetic separation of functionalized magnetic particles

The processing of wines with enzymes is a process chain in which losses of biocatalyst are unavoidable. A promising technique for the minimization of these losses and for the reduction of processing time is the high‐gradient magnetic separation in combination with enzymes, which are immobilized onto functionalized magnetic particles. When magnetizable particles are used and magnetic separation is applied to separate these particles from nonmagnetizable particles and solutes, the enzymes can be recycled and used for several production batches. The magnetic filter used in this study had a filter matrix with concentrically stacked circular rotor and stator plates which are arranged in an alternating order. Different geometries of the filter plate notches were examined to optimize the reproducibility of particle retention. In computational fluid dynamic studies, the influence of the notch geometries on the shear rate generation was analyzed for the rinsing procedure. Separation experiments with an optimized geometry of the filter plates were carried out in water and white wine suspensions.

Development of a novel disposable filter bag for separation of biomolecules with functionalized magnetic particles

The integration of disposable magnetic filters in combination with functionalized magnetic particles represents a fast and cost‐effective alternative for enzyme purification in comparison to solid/liquid separation by means of centrifugation followed by chromatographic purification. The main advantage of the particle‐based process is the solid/solid/liquid separation in one step combined with disposable equipment. Furthermore this combination provides the possibility to also process biocatalytic reactions in cell‐containing media into disposable equipment with preimmobilized enzymes onto the magnetic particles. The focus of the presented study is on the design and performance of a disposable filtration unit consisting of a plastic bag with an inlet and outlet and a stainless steel filter matrix. During magnetic separation, the magnetic particles selectively retard at the filter matrix due to the magnetic force, which counteracts the drag force. It was found that the length of a lengthwise aligned filter matrix should be longer than the magnetic pole surfaces in fluid flow direction. Hereby, a filtration capacity of 5.6 g magnetic particles was measured with a loss of below 0.5%. Introducing a two‐phase flow optimizes the cleaning of the bag after a magnetic filtration. The procedure offered a high cleaning efficiency. Herewith, the cleaned filter unit could be discarded with minimum losses of product and magnet particles.