Mechanism of Effect of Microwave Modification on Pulverized Coal Combustion Properties

Abstract

The mechanism of microwave modification on facilitating the combustion properties of pulverized coal (PC) was investigated. Experimental researches on granularity and functional group as well as combustion properties of PC before and after modification were carried out. Micromorphology observation indicated that the size of PC particles was relatively small, which was in accordance with the results of granularity analysis of PC. FT-IR (Fourier-transform infrared) spectra of two PCs indicated that the proportion of the functional groups with high activity increased after microwave irradiation. Furthermore, no valid effect of microwave was found on carbon matrix except small variations in PC particle size, which only led to subtle improvement in combustion of residual coke. Activation energies of Yungang and Yangquan PCs in temperature zone between 450—650 °C were reduced by 12.00% and 10.13%, respectively, which meant that microwave modification might effectively facilitate the combustion properties of PC. Nevertheless, decrease in activation energies of residual cokes was 3.56% and 3.67% respectively, which was subtle and can be regarded as the result of smaller particle size produced by microwave irradiation.