Research Status of Microwave Coal and Rock Thermal Action at Home and Abroad

China is endowed with abundant coal resources, making the clean, low-carbon, and efficient development and utilization of deep coal resources a crucial pathway to ensure national energy security while aiding in the achievement of the country’s “dual carbon” goals. Microwave heating of coal and rock exhibits several advantages, including enhanced methane desorption, selective heating capabilities, conservation of water resources and time, as well as the ability to eliminate water lock effects. These characteristics provide significant benefits over conventional heating methods. This paper discusses the unique features associated with microwave heating in coal and rock production and reviews the current research landscape regarding this technology. Most existing studies concentrate on theoretical analyses, experimental investigations, or numerical simulations aimed at establishing multi-physical field coupling models to elucidate the mechanisms underlying heating processes, temperature variation patterns in coal and rock materials, as well as how temperature influences recovery rates. Additionally, some research efforts are directed towards developing experimental system devices. However, due to the inherent complexities associated with microwave heating techniques along with variable environmental conditions affecting coalbed methane during practical engineering applications remain inadequately addressed.