Continuous-Flow Microwave Reactor for High-Performance Heating of a Dynamic Chemical Reaction System

Continuous-flow microwave reactors find widespread application in chemical production. However, dynamic changes in the dielectric constant of reactants result in a low microwave energy efficiency. This paper reveals a circular waveguide developed using a meta-surface unidirectional propagation of microwaves. This waveguide was integrated into a continuous-flow heating system that efficiently heats materials with varying dielectric constants. A multiphysics model incorporating electromagnetic, fluid heat transfer, and chemical engineering has been built to analyze the microwave heating performance under different loads. Based on simulation and experimental findings, the meta-surface can achieve an energy efficiency of over 90% for loads with dielectric constants from 10 to 80. Moreover, a continuous-flow heating experiment conducted for biodiesel production indicated that meta-surfaces can enhance the heating efficiency by over a quarter. This research presents a promising approach toward efficient continuous-flow microwave heating, which can potentially revolutionize large-scale chemical production in industry.