Research Of Key Technology For Microwave Coal Desulphurization

Coal is the richest fossil fuel on the earth. So far coal accounts for more than 25% of the world’s primary energy consumption. Because there are sulfur and sulfur compounds in coal. During the process of coal conversion and combustion SO2 and H2 S would be generated which will lead to serious air pollution. However, with the increasing demand for energy coal will play the main role in the future for a long period. To change coal as an effective and high-quality fuel by desulphurization is strategically significant to grantee continuous coal-base energy supply, rapid and sustainable economic development and livable environment. As microwave technology has been successfully applied to kinds of industry and civilian living, people tends to get a better and better understanding of microwave. With the combination of microwave technology and traditional desulphurization method excellent effect is expected. When microwave power is applied for material processing the reaction condition is mild, the reaction is rapid and the reaction is easy to control. Additionally, microwave is harmless to the organic matter contains in coal. Applied microwave power to coal desulphurization is a new and promising approach.This paper is based on the National 973 key projects “Basic research of low-quality coal for upgrading utilization on large-scale”. Furthermore, this paper is the results of further study on the basis of current coal desulphurization research.Firstly, this paper described laboratory desulphurization equipment. Each section of the equipment was presented in detail. Two kinds of microwave reaction cavity were designed and one of them was fabricated and measured. Measurement results agreed with simulated ones excellently which means a perfect reaction place can be offered by the cavity.Secondly, information about electromagnetic properties of coal and sulfur compounds is indispensable for coal desulphurization. Dielectric characterization of coal was measured with transmission and reflection method in the laboratory. To overcome the imprecision of transmission and reflection method for low-loss material, an approach of cavity perturbation based on circular substrate integrated waveguide cavity was suggested. Results based on simulated data show that great precision can be achieved by the method.Lastly, we proposed to investigate the mutual effect of microwave and coal through simulations carries on models of coal. Models can imitate the random stack of coal granule both on two-dimensions and three-dimensions. Models were built through Matlab program and exported to HFSS for simulation. The permittivities of models for simulation are set based on tested results. Simulated results can provide foundation for investigation of propagation and attenuation characteristic.The method applied in this paper and conclusions of this paper can act as theory guidance for industry coal desulphurization and benefit for further research.