(11e) Development of Membrane Based Operations for Emerging Separations Challenges

Membrane based separations are attractive for a number of reasons such as easy scale up, lower operating cost and the potential for significant process intensification. For applications in bioseparations linear scale up is important given the regulatory approvals needed for a manufacturing process. Catalytic membranes on the other hand, provide the possibility of combining reaction and separation into one unit operation which leads to significant process intensification. This could enable the economic conversion of waste biomass to bio-based chemical intermediates. In this presentation the potential for membranes in each of these areas will be discussed.

Biopharmaceutical manufacturing processes make use of cell lines to produce therapeutics such as monoclonal antibodies, fusion proteins etc. Membrane based processes such as membrane adsorbers, ultrafiltration and virus filtration are routinely used in the purification of these products. Here the focus will be on validation of virus clearance, which is a major challenge in the manufacture of biopharmaceuticals. Today, biopharmaceutical manufacturing processes are typically run in batch mode. Further there is growing interest in complex therapeutics, e.g., live attenuated virus vaccines, viral vectors for delivery of gene therapy, VLPs, plasmid DNA, cell-based therapies. These more complex therapeutics create additional challenges when attempting to validate virus clearance. Some of these challenges will be discussed. In addition, there is a great deal of interest in developing continuous biomanufacturing processes in order to minimize batch to batch variation.

The overall agricultural industry contributes more than 25% to world greenhouse gas emissions. Agricultural residues represent an abundant source of fuels and chemical intermediates. Here lignocellulosic biomass hydrolysis and dehydration has been conducted using a synthetic polymeric solid acid catalyst consisting of dual polymer chains grafted from the surface of a ceramic membrane. These novel, polymeric solid acid catalysts are superior to cellulases enzymes as they can be operated at a higher temperature and at a much higher hydrolysis rates. These catalysts are stable and maintain high catalytic activity over repeated runs. Moreover, they can be easily regenerated and are environmentally friendly. These polymeric solid acid catalysts can be used not only for hydrolysis but also dehydration of cellulose leading to the production of 5-hydroxymethylfurfural (HMF) or levulinic acid. By using a catalytic membrane, reaction and separation can be combined into a single unit operation leading to an intensified process.