Biocatalytic process intensification using deep eutectic solvents in microflow systems for sustainable waste valorization – BioInDES

The potential of biocatalytic processes as a key enabling technology for sustainable manufacturing is far from being realized. The main challenge is low process productivity related to typically low substrates and/or products solubilities in water and enzyme deactivation in organic solvents or at high product concentrations. The use of deep eutectic solvents (DESs), an emerging class of green media, can substantially improve solubility and decrease process cost, energy consumption, and waste generation. Stabilization of biocatalysts can be achieved by biocatalyst immobilization, enabling also long-term utilization in continuous flow systems. Reactor miniaturization offers the possibility to obtain high biocatalyst loads, continuous process operation, and excellent mass and heat transport, leading to high biocatalyst and volumetric productivities. Moreover, better process control in microflow systems, the possibility of process integration for in situ product removal, and telescoping of multienzymatic reactions can significantly contribute to biocatalytic process intensification. In this proposal, we wish to develop continuous bioconversion of CO2 into methanol and of furfural to its high-value derivatives using DESs and immobilized biocatalysts in microflow systems comprising multienzymatic reactions and integrated product removal. The project will encompass 5 work packages and WP1 will focus on the definition of both reaction systems comprising biocatalyst screening, reaction analytics, and kinetics evaluation in batch systems. Various dehydrogenases and transaminases will be tested and selected for use in the microflow system. In WP2, a rational design of DESs for selected enzyme-catalyzed reactions will be performed, where also new DESs will be prepared and experimentally and theoretically characterized to get a deeper understanding of the interactions between the components that form DESs and other reaction compounds. In WP3, immobilization of selected biocatalysts in microreactors aiming to provide also efficient cofactor regeneration will be studied. Various advanced immobilization techniques will be tested, and the resulting biocatalysts will be systematically characterized. WP4 will focus on model-based reactor and process engineering aiming to develop integrated processes of methanol and furfural derivatives production in DESs within highly efficient microscale apparatuses. Finally, a detailed techno-economic study and environmental impact assessment of integrated biocatalytic processes by using standard calculations and computer-aided methods will be performed in WP5. Findings originating from this study will extend the knowledge on biocatalytic reactions using DESs and particularly their use in microflow systems aiming to intensify these processes. This will further spur industrial application of sustainable biocatalytic processes to address the global warming problem and waste valorization contributing to achieving the targets set by the European Green Deal.