Microwave absorption properties of organic sulfur compounds in coal: application of desulfurization

According to the analysis of the characteristics of coal samples, organic sulfur compounds with different structures were selected and their microwave absorption performance was observed in the range of 2.0 GHz to 8.0 GHz. The relationship between absorption performance and desulfurization efficiency was studied by the microwave desulfurization experiment. Results showed that microwave frequency change slightly affects the real part of the complex dielectric constants of organic sulfur compounds. In contrast, it had a significant effect on the imaginary part of complex dielectric constants, dielectric loss tangent, microwave penetration depth and the absorption coefficient, except for the imaginary part of complex dielectric constants and dielectric loss tangent of thiophene compounds. The polarization ability of compounds in the microwave field followed the order: thiophene > mercaptan > thioether, while the efficiencies of mercaptan and thioether for absorbing electromagnetic energy and transforming it into thermal energy were more substantial than that of thiophene. The stronger microwave absorbing performance, the higher the desulfurization rate. Mercaptan and thioether compounds were more accessible to remove than thiophene from coal by microwave radiation and chemical additives.