Green and Highly Efficient Aldol Condensation Technology by a Continuous Flow Microreactor and Reaction Kinetic

Aldol condensation is a key strategy for carbon–carbon bond formation, but its application is usually limited by environmentally unfavorable catalysts and inefficient heat and mass transfer. Microreactor technology provides a highly efficient and environmentally friendly alternative for aldol condensation. In this study, a continuous-flow microreactor system for aldol condensation of benzaldehyde and acetone was developed using choline hydroxide ionic liquid as a catalyst in an ethanol–water solvent system. The effects of key operating parameters, including reaction temperature, catalyst concentration, and residence time, on reaction performance were systematically scrutinized. A 90% yield was achieved at 30 °C with approximately 4 min residence time, indicating remarkable process intensification. Moreover, the ionic liquid catalyst could be readily recovered and reused with good yield stability after four cycles. Furthermore, the reaction kinetics of benzalacetone synthesis in the microreactor were delved into, and the relative kinetic parameters were determined.