Study On A Novel Microwave Chemical Reactor

Microwave chemistry is one of the fastest growing scientific fields. Microwave chemical reactor plays an important role in microwave chemical engineering. The design of microwave chemical reactor is a complicated engineering problem and needs not only microwave techniques but also chemical theories. So far, due to expensive high-power magnetrons and magic T, most of high-power microwave chemical reactors are too costly to be widely applied in chemical industry. In this paper, a novel low-cost microwave chemical reactor with multi-magnetron based on noncoherent power synthesis is presented.The shape and the volume of the cavity are obtained. Then several different reactor models are constructed according to the volume of reactants and the basic design principle. Then the variation of electromagnetic field distribution with respect to the polarization and location of the multi feeds, is simulated using finite-differential time-domain (FDTD) method. Simulation results show that the coupling between the two feeds with polarization vertical to each other is weaker than that of those with polarization parallel to each other. Moreover, the power density in the cavity with two magnetrons working simultaneously is much higher than that with only a single magnetron.It is important to learn the variation of permittivity with time during the chemical reactions, which will help us to know the properties of microwave power absorption in the reactants. In this paper, the measurement of the effective permittivity of the 1,2-DPE synthesis is investigated. The reflection coefficient is measured during the reaction in a sampling way, and the real part and the imaginary part are calculated later. Measurement results show, the real part of effectivepermittivity of the reactive solution varies little with time, while the imaginary part varies obviously with time. The results provide some useful information to the design of microwave chemical reactor.The test of the microwave chemical reactor with double-magnetron shows that the power of the new reactor is increased largely and temperature distribution within the reactor is relatively uniform. Simulation results are in agreement with experiment results, which demonstrate the validity of the numerical simulation.In summary, a low-cost but high-power microwave chemical reactor with double-magnetron based on noncoherent power synthesis is researched. The technique has a great potential in the popular application of microwave in chemical industry.