Desulfurization of High Sulfur Coal Leached with H_2O_2 and NaOH by Microwave Irradiation

摘要

Coal desulfurization has been regarded as an effective pretreatment for clean fuel and less environmental pollution. The microwave irradiation was used to desulfurize the Nantong coal leached with H_2O_2 and NaOH. The results showed the desulfurization rate of the coal is very low by directly microwave irradiation, while the coal samples leached with H_2O_2 and NaOH by microwave irradiation could effectively improve the desulfurization rate. The optimum desulfurization conditions were obtained as 10-min irradiation time, 800 W irradiation power, particle size below 74 μm, 1:1 concentration ratio of H_2O_2:NaOH, in which the desulfurization rate reached 51.14% of the total sulfur content. Attenuated total reflectance Fourier transform infrared (ATR-FTTR) spectra of coals structure before and after treatment have shown the bands in both coals changed slightly except the relative intensity of some absorption ones. It can be found that most of FeS_2 and -S-S-functional groups transferred after treatment, while -SH and -S=O- had almost no changing by ATR-FTIR spectra analysis. The structures of coal matrix would not be broken by microwave irradiation in reasonable the reaction conditions.