Improved slit-shaped microseparator and its integration with a microreactor for modular biomanufacturing

Modular and distributed biomanufacturing requires continuous flow microreactors integrated with efficient separation units operating at comparable time scales: biphasic reactive extraction of 5-hydroxymethyl furfural (HMF) by fructose dehydration is an excellent example. The liquid–liquid extraction (LLE) and fast reaction kinetics in biphasic microchannels can immensely benefit from a downstream microseparator enabling separation of an HMF-rich organic extract and an aqueous raffinate. Here we demonstrate the successful implementation of an effective slit-shaped microseparator for eleven organic-water biphasic systems. The microseparator successfully separates six of these over reasonable flow rates. The ratio of capillary and hydraulic pressures qualitatively rationalizes the separation performance, while a transition to non-segmented flow patterns correlates with performance deterioration. Acids and salts, integral parts of the chemistry, significantly expand the flow rates for efficient separation enabling a broader slate of organic solvents. For the MIBK/water biphasic system, we demonstrate perfect separation performance over a 16-fold variation in the organic to aqueous flow ratio. Here we also integrate the microseparator and extractive microreactor into a modular system and achieve an HMF yield of up to 93% – the highest reported fractional HMF productivity of 27.9 min−1 – at an ultrashort residence time of 2 s. This unprecedented performance is maintained over a 50-fold fructose concentration range and is stable with time-on-stream. This microseparator exhibits a ten-fold reduction in separation time and substantial energy savings over conventional decanters. As such, it holds promise for continuous process intensification and modular biomanufacturing.
This article was originally published in Green Chemistry. The version of record is available at:
Bhattacharyya, Souryadeep, Pierre Desir, Sebastian Prodinger, Raul F. Lobo, and Dionisios G. Vlachos. 2021. “Improved Slit-Shaped Microseparator and Its Integration with a Microreactor for Modular Biomanufacturing.” Green Chem. 23 (10): 3700–3714.