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The desulfurization effect of Ningxia Shuangma coal (SM) with an acetic acid-hydrogen peroxide system assisted by microwave, ultrasonic and ultraviolet light was compared. The results show that microwave-assisted desulfurization has the best effect. When the microwave power is 900W, the irradiation time is 5 min, and the volume ratio of acetic acid to hydrogen peroxide is 1:10, the desulfurization rate can reach 55.82%. Moreover, microwave-assisted desulfurization can effectively improve the removal effect of organic sulfur. XRD, XPS, SEM and other characterization showed that microwave assisted can effectively reduce the mineral content, expose more sulfur-containing groups, and improve the desulfurization effect. The desulfurization rate of three sulfur-containing compounds is: dibenzyl sulfide > diphenyl sulfoxide > benzothiophene. With the increase of intensity of the applied electric field, the C–S bond gets easier to fracture, the applied electric field can reduce the reaction energy barrier, is a benefit to the reaction. [ABSTRACT FROM AUTHOR]

BACKGROUND: Microwave‐assisted and Fenton reagents were combined to enhance the removal effect of sulfur from coal. The coal samples before and after desulfurization were characterized by various testing methods such as X‐ray photoelectron spectroscopy, X‐ray diffraction and scanning electron microscopy. RESULTS: The microwave–Fenton system showed the best desulfurization effect with a desulfurization rate of 77.52% at a microwave power of 800 W and irradiation time of 5 min, which was 82.96% higher than the maximum desulfurization rate of Fenton reagents alone. The desulfurization rates of pyrite sulfur, organic sulfur and sulfate sulfur can reach 88.76%, 58.77% and 59.33%, respectively. CONCLUSION: The minerals in the treated coal samples were significantly reduced. The microwave–Fenton system can generate a large number of hydroxyl radicals to break the CS bond, while exposing more sulfur‐containing groups to the reagents, resulting in more oxidation of low‐valent sulfur and sulfoxide to high‐valent sulfone and sulfate sulfur. The model compound removal effect was measured, dibenzyl sulfide > diphenyl sulfoxide > diphenyl sulfoxide > dibenzothiophene, while the microwave–Fenton system could significantly enhance the desulfurization effect of the above four model compounds. It was found that with the increase in applied electric field, the reaction energy barrier decreased and the CS bond was more easily broken, which was favorable to the reaction. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]