Modelling of the Ultra- and Microfiltration Process

Membrane processes have been a promising alternative to other separation processes for some time. For instance one separation task within the biotechnological industry is the separation of products (enzymes) from the fermentation broth which furthermore contain cells and cell debris. The separation is carried out using centrifugation which is a batch process and therefore an inherently expensive separation process. This process could be replaced with an continuous membrane process that is microfiltration. The major problem with the replacement is the severe fouling of the membrane one is faced with. This will cause a large decrease in the flux (a 90% decrease compared to the pure water flux has been observed). Due to the fouling an in situ cleaning of the membrane would be very promising technique to prevent the fouling. Such a cleaning method has been developed in the membrane group in collaboration with the membrane group at the Department of Biotechnology. The cleaning method has been named the backshock technique. The microfiltration process in combination with the backshock technique has been successfully applied to industrial liquids like beer and milk.
The optimisation of the process has until now been carried out in a more or less empirical way. It would be of great interest to perform the optimisation in a more general way for example with the aid of models for the process.