Microwave Liquid Heating in Miniature Reactors

This Chapter considers theoretical and experimental results for MW-assisted liquid heating in miniature coaxial and strip-based reactors. Initially, general EM, thermal, and hydrodynamic equations are given and discussed. Because of the strong and complicated dependence of liquid parameters on frequency, temperature, and pressure, the approximate analytical expressions for dielectric permittivity for a couple of reference liquids, namely, ethanol and methanol, are obtained fitting published experimental results. The coaxial waveguide reactors are treated analytically and numerically, including the liquid and thermal effects under MW heating. Several new designs are proposed to overcome some disadvantages of classical coaxial waveguide reactors. Among them are multi-conductor and  glass-metal coaxial reactors. Accelerated chemical synthesis can be reached in a thin liquid-film rotating reactor fed by microwaves, and the designs and intermediate experimental results for these reactors are given and discussed. 158 references are given to readers. 43 figures and 10 tables are included in the text.