To explore the heating characteristics of activated carbon in a microwave field, the effects of microwave irradiation power, the radius and physical properties of activated carbon, and a symmetrical waveguide on the heating characteristics of activated carbon in a microwave field were studied by experiments and simulation. This study distinguishes itself from previous works by focusing on high-power microwave heating (up to 800 W) and providing a comprehensive analysis of key parameters such as radius, thermal conductivity, magnetic conductivity, and dielectric constant. Additionally, the use of symmetrical waveguides and their impact on heating efficiency represents a novel contribution to the field of microwave-assisted flue gas desulfurization. According to the results, with the increase in microwave irradiation power, the heating rate of activated carbon in the microwave field increases, and the final temperature also rises. Waveguides significantly influence the heating characteristics of activated carbon. When multiple waveguides act on the same microwave field, electromagnetic waves interfere with each other and affect the distribution and intensity of the electromagnetic field. With an increase in the imaginary part of the relative permittivity, the real part of the relative magnetic permeability, and the thermal conductivity of the heated material, the heating characteristics of activated carbon in the microwave field are improved. This study provides a theoretical model for the heating characteristics and temperature distribution of activated carbon in a microwave field under high irradiation power.

Simulation of microwave heating characteristics of activated carbon
    Abstract
    1 Introduction
    2 Establishment of an experimental system for microwave heating
        2.1 Experimental materials and instruments
        2.2 Experimental system and process of microwave heating activated carbon
    3 Microwave heating model based on COMSOL multiphysics
        3.1 Geometric model
        3.2 Physical properties of activated carbon
        3.3 Governing equation
            3.3.1 Electromagnetic wave frequency domain
            3.3.2 Solid heat transfer
        3.4 Boundary condition
            3.4.1 Impedance boundary condition
            3.4.2 Port boundary conditions
        3.5 Mesh
        3.6 Research steps
            3.6.1 Frequency domain
            3.6.2 Transient
        3.7 Solver
    4 Results and discussion
        4.1 Simulation and experimental verification of heating characteristics of activated carbon in the microwave field
        4.2 Effect of the radius of activated carbon on the heating characteristics
        4.3 Effect of thermal conductivity on the heating characteristics of activated carbon
        4.4 Effect of magnetic conductivity on the heating characteristics of activated carbon
        4.5 Effect of dielectric constant on the heating characteristics of activated carbon
        4.6 Effect of two-side waveguides on the heating characteristics of activated carbon
    5 Conclusions
    References

• Yulei Qiao(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China) Corresponding author
• Hang Chen(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Sihan Liu(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Anqi Xia(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Yeshun Tian(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Changliang Wu(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Xiuzhi Zhang(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Shuxia Feng(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Xiao Xia(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Guangbin Duan(School of Material Science and Engineering, University of Jinan, Jinan 250022, Shandong, China)
• Liqiang Zhang(National Engineering Laboratory for Reducing Emissions From Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, Jinan 250061, Shandong, China)