Characteristic analysis of complex antioxidant enzyme inhibitors to inhibit spontaneous combustion of coal

Complex antioxidant enzyme inhibitor (SC), as an innovative technology was proposed, which mainly includes polyethylene glycol-Cu,Zn superoxide dismutase (PEG-SOD), Mn catalase (CAT) and sodium dodecyl sulfate (SDS). It exhibits excellent performance in inhibiting the low-temperature oxidation of coal. This study includes wettability of SC solution and the thermal characteristics of SC suppressing the self-heating of coal. For wettability of SC solution, it was found that the nuclei of the PEG polymer could adsorb hydrophilic groups of SDS to form an outer PEG polymer layer through chemical shift alterations, and the inner SDS tail groups were adsorbed at the hydrophobic coal sites, leading to an SC solution with excellent wetting ability on the coal surface. For the thermal characteristics analysis, the SOD and CAT contained in SC could quickly neutralize superoxide radicals through a disproportionation reaction below 90 °C; the PEG, with the thermoplastic properties of SC, could fuse to form a colloid that could wrap onto the coal surface to form a protective layer below 150 °C. Research results indicated, as for coal-SC, that chain propagation reactions were terminated, homolysis of chemical bonds to generate new free radicals was prevented, and the free radical concentration obviously decreased on the coal surface; the relative content of C O groups obviously decreased, that of C C/C H groups gradually increased, and those of C O/O C O and O C O groups remained almost constant with increasing temperature; oxygen adsorption was significantly reduced, leading to an obvious decrease in oxidation of active groups to form surface oxides.