Development of Sustainable Biocatalytic Furfurylamine Production in a Magnetic Field-Assisted Microfluidic Reactor

The increasing demand for furfurylamine (FA), a versatile biobased building block, necessitates the development of efficient and sustainable production processes. This study presents a continuous biocatalytic process for the amination of furfural (FUR) to FA, aligning with green chemistry principles and circular economy strategies. A systematic screening of ω-transaminases (ω-TAs) and amine donors identified N-His6-ATA-wt and (S)-(−)-α-methylbenzylamine as the optimal pair, achieving a 96% FA gross yield within 30 min at equimolar substrate concentrations, surpassing previously reported ω-TA-based FA productions. To enable biocatalyst long-term use in continuous processes, the enzyme was covalently immobilized on synthesized and functionalized magnetite nanoparticles (MNPs) using glutaraldehyde (GA) as a cross-linker. At optimized immobilization conditions, 92.8% recovered activity was achieved with 80 mg enzyme/g dry MNPs and 2% (v/v) GA in a batch process. The immobilized biocatalyst was integrated into a custom 3D-printed magnetic field-assisted microreactor and evaluated in continuous-flow operation for 18 days. The system reached a maximum space-time yield of 1.07 g/(L h) and a total turnover number of 2.04 × 107. These results, along with favorable green chemistry metrics, highlight the potential of this integrated approach─combining enzyme engineering, nanomaterials, and flow technology─for scalable and sustainable FA production.