Yeast filtration with rotating membrane filtration – a new approach for an economical recovery of beer form surplus yeast

The recovery of beer from surplus yeast is to date an economical business case only for large breweries. In this work, a here novel process with rotating ceramic microfiltration membranes is used. This allows a very high lift force to be achieved while still maintaining a small transmembrane pressure to reduce the formation of a fouling layer. The results show that long running times (between cleanings) are possible, limited only by the change in the rheological properties of the suspension due to thickening. From a so-called "Inflexion Point" (IF), the filtration behavior changes abruptly. The aim of the work was therefore to use machine learning aided modeling to predict the IF from experimental data in order to optimize the process and to achieve the most economical conditions. The economic efficiency depends on the space-time yields. The results show that a significant improvement in economic efficiency could be possible with the help of modeling and this special kind of filtration technology. However, the economic efficiency depends finally on the conditions in each individual brewery.