Pulsatile crossflow improves microfiltration fractionation of cells and proteins

The application of pulsatile crossflow is known to mitigate fouling and enhance permeate flux during filtration of simple one-component suspensions. However, previous studies lack a systematic investigation of the effect on pulsation frequency and amplitude on permeate flux, but also on solute transmission during fractionation processes, which hinders industrial application. We used a model feed containing yeast cells as deposit forming material and bovine serum albumin as permeating solute to investigate the influence of pulsatile crossflow with a rather low frequency of 0.1–0.5 Hz on permeate flux and protein transmission in comparison to conventional steady crossflow microfiltration. We found that pulsatile crossflow microfiltration has the highest effect, when it is applied at high transmembrane pressure, high pulsation amplitude, and a frequency above 0.2 Hz. Then, besides enhancing the permeate flux up to 25% (from approximately 200 to 250 L m⁻² h⁻¹), pulsatile crossflow is able to double the protein transmission (from approximately 30 to 60%), which has a strong beneficial effect on fractionation efficiency. Further to that, this work contributes to enhance the implementation of pulsatile crossflow filtration by suggesting an easy to implement and scalable pulsatile filtration plant as well as suitable process conditions.