In-line product separation in a continuous oscillatory flow bioreactor as process intensification and product inhibition mitigation strategy

A Continuous Oscillatory Flow Bioreactor (COFB) was developed to enable the processing of lignocellulosic biomass at high solid loadings of up to 23 % and to allow for in-line product separation. The enzymatic saccharification conducted in the COFB yielded glucose concentrations of up to 50 g/L at a residence time of 3 h, corresponding to a yield of 0.2 g_glucose/g_substrate and an enzymatic productivity of 10 g_glucose/g_enzyme. The system incorporated precise quantification of the minimal energy input for oscillatory mixing, resulting in a specific energy demand of 6 Wh/kg_glucose. Notably, the integration of in-line product separation enhanced enzymatic productivity by up to 40 %. Compared to conventional shaking flask experiments, process intensification in the COFB led to a 1.7-fold increase in volumetric productivity and a 1.6-fold reduction in residence time. These findings underscore the potential of the COFB as a scalable and energy-efficient platform for biorefinery applications.