Innovation of Expanded-Bed Adsorption by Integrating Simulated Moving-Bed Technology.

Bio-based industries need efficient downstream solutions to process complex streams. This was addressed through a technology integration approach, where expanded-bed adsorption (EBA) is integrated with simulated moving-bed (SMB) technology. Current work involved adaptation of an SMB apparatus and control principle to implement expanded-bed level control. As an outcome, EBA-SMB technology was successfully applied for purification of γ-aminobutyric acid (GABA). This resulted in two-fold increase in productivity and a GABA purity ≥ 92 % in one step from unclarified fermentation broth, compared to ≥ 93 % purity in case of clarified broth and packed-bed SMB. These results proved that EBA-SMB technology is able to enhance process efficiency and economics of bioprocesses.

Hybridizing Simulated Moving Bed and Electrodialysis: Product Purification and Eluent Regeneration.

Complex streams in bio-based industries require efficient downstream processing units. Simulated moving-bed (SMB) chromatography is known to improve process efficiency by reducing resin and buffer requirement, but it can be further enhanced by technology hybridization. In the current experiments, an SMB system has been integrated with a bipolar electrodialysis (BPED) system. SMB purified γ-aminobutyric acid (GABA) from a clarified fermentation broth while BPED processed the product-containing eluent stream into recyclable eluent and purified product streams. The continuous operation did not result in any impurity accumulation.

Expanded Bed Adsorption of γ-Aminobutyric Acid from E. coli broth by CS16GC and IRC747 Resins.

Expanded-bed adsorption (EBA) is an efficient downstream technology that enhances the techno-economic potential of bio-based industries. However, application of EBA for bulk biochemicals requires the use of industrial resins. Therefore, two cation exchangers, namely, gel-type CS16GC and porous IRC747, were tested to purify γ-aminobutyric acid (GABA) from unclarified E. coli fermentation broth. Experiments compared the impact of gel-type and macroporous resin properties on the EBA process performance. As an outcome, the gel-type resin exhibited higher GABA binding capacity of compared to that of macroporous resin. This was due to improved hydrodynamics and uniform flow distribution in the case of gel-type resin. Further, CS16GC effectively removed ≥ 99 % of impurities and achieved ≥ 97 % GABA yield.