(519g) Process Optimization of Constant Flow Series Filtration of Bioprocess Fluids

Normal flow microfiltration and nanofiltration of biological fluids are typically conducted under constant pressure or constant flow conditions. Often, a prefilter is installed upstream of the final, sterilizing-grade filter to increase the final filter lifetime and thereby improving filtration economics. There have been previous treatments on optimization of prefilter and final filter configurations, but primarily for the case of constant pressure operation. This work focused on process optimization for constant flow operation, which involves a different set of considerations compared to constant pressure operation.

A fouling model that accounts for both particle blocking and particle adsorption mechanisms was applied to a new class of prefilters with polyethersulfone membrane that serve to protect microfiltration and nanofiltration final filters. It was demonstrated that a fit of the constant flow filtration data at one prefilter to final filter area ratio could be used to predict the constant flow filtration performance at any other area ratio. The model can be used to determine economically optimal process designs including optimal process flow rate and optimal prefilter to final filter area ratio. A practical test methodology that can be used to rapidly and efficiently derive the model parameters that are needed for the optimization calculations will be elucidated.