Fixed-bed Reactor

Fixed-bed reactors with microporous supports present an alternative to a stirred tank reactor for the cultivation of adherent animal cells, as they enable a continuous cultivation at a low shearing stress for high volume-related cell densities.

A significant advantage of this system is contained in the possibility to precisely set retention times of viruses and monoclonal antibodies under process conditions.

The oxygen supply is a particular problem in the scale-up of fixed-bed reactors, as the height of the bed is limited due to the oxygen depletion. A fixed bed may have an axial through flow for small construction lengths of up to approx. 10 cm without the occurrence of an oxygen limitation in the upper area of the fill. A further scale-up is carried out through a radial through flow of the fixed bed. The cultivation of demanding cells is also possible through the selection of an appropriate support.

In comparison with suspension reactors fixed-bed reactors are more powerful in terms of the volume-specific cell density and productivity which is able to be achieved. As a result of the cell  retention in the fixed bed integrated separation processes with ceramic diaphragms are simple to achieve. The operation of a fixed bed is also very simple and inexpensive.