(226c) Sustainability Issues in Membrane Systems for Bioprocessing

Although product yield and purity tend to be the dominant issues in the development of membrane systems for bioprocessing applications, membranes can also play a major role in the development of more sustainable bioprocesses.  This talk will highlight several examples of sustainability issues and opportunities in membrane technology for bioprocessing applications.  Ultrafiltration is currently used in the final concentration and formulation of nearly all recombinant protein products.  In addition to giving very high product yield and quality, ultrafiltration also provides significant energy savings relative to alternative (e.g., thermal) processes for product concentration.  Membrane chromatography can be used to significantly reduce the energy costs compared to traditional packed columns due to the significant reduction in the required pressure drop in the highly porous membranes.  There are also exciting new opportunities for using membrane systems to develop continuous bioprocesses with dramatically smaller environmental footprints.  These continuous processes are based on perfusion bioreactors, e.g., hollow fiber membrane bioreactors with the cells immobilized in the shell region of a hollow fiber module or more traditional bioreactors in which the cells are continuously recycled by a microfiltration unit.  New research on continuous countercurrent tangential chromatography has demonstrated that this technology can provide continuous product capture using high performance resins that are processed as a flowing slurry through a series of static mixers and hollow fiber membrane modules.  These continuous systems have productivities that are 10-100 times greater than conventional batch processes, dramatically reducing capital costs and environmental impact.  Membrane systems should continue to play a critical role in the development of sustainable bioprocesses.