The interaction between microwave and coal: A discussion on the state-of-the-art

Much attention has been put on microwave heating technologies for coal. However, there is relatively little information regarding the interaction between coal and microwaves. In this paper, the mechanism of microwave heating, and the relevant research on the interactions between coal and microwaves are studied in detail. In addition, the factors that influence and affect the interaction between coal and microwaves are summarized. This paper also examines previous research conducted on the numerical simulation of coal microwave interactions, and the future development of multi-physical field simulation by COMSOL Multiphysics. The non-thermal effect and hot spot effect of microwaves are also studied. The aim was to combine the microwave heating experiments and numerical simulations of coal, which would not only ensure the reliability of the established model but also reduce the number of experiments required by numerical simulation; thus reducing the experimental cost of coal microwave treatment. The paper provides a theoretical basis for the industrial utilization of coal microwave treatments. Moreover, these efforts have made possible the large-scale application of microwave processing methods for coal.