Enhanced power density uniformity for microwave catalytic reactions adopting solid-state generators: Comparison with magnetron technology

Endothermic processes at high temperature are typically implemented through heat transfer techniques based on thermal conduction from the surface. This situation implies non-uniform radial temperature within the load causing a lower quality process. The microwave (MW) based volumetric heating is the ideal alternative to improve these processes, but axial -thermal gradients appear for the presence of resonant standing waves. In the current research, a laboratory-prototype has been developed to experimentally validate an implemented Finite Element (FE) model. The efficiency and the non-uniformity have been assumed as objective functions, and the Pareto-fronts have been evaluated to compare Magnetron Based Systems (MBS) and Solid-state Based Systems (SBS). The physical effects related to the porosity of the subsceptor (SiC) have been numerically evaluated in the range from 0 to 0.6. The higher the porosity the more uniform the heating pattern. At equal efficiency conditions, the SBS can achieve a 20% reduction of non-uniformity with respect to MBS. The statistical distribution of the electric field in SBS is right-skewed quasi-Gaussian, meaning that the most frequent power density level is close to the mean value. SBS defines Pareto-configurations that are dominant with respect to those based on IVIBS.