Effectiveness of catechin and poly(ethylene glycol) at inhibiting the spontaneous combustion of coal

Synchronous thermal analyses and kinetic studies on a caged-wrapping and sustained-release type of composite inhibitor retarding the spontaneous combustion of low-rank coal

“…Catechin (CC), the natural polyphenol extracted from green tea plants, presents valuable in a variety of research fields including biomedicine [26], anti-aging [27] and food science [28] due to its potent antioxidant activity. In addition, as reported in previous research, (+)-catechin can function as a highly effective chemical inhibitor towards coal spontaneous combustion by eliminating crucial peroxy radicals during oxidation [29]. Taking full account of characteristics of both PAA/SA and CC, a sustained-release type of composite inhibitor is proposed.…”

“…With the increase of temperature, the three-dimensional cross-linked network gradually depolymerizes and becomes sparse [25], as a result, the internal active CC is sustained-released to the surrounding coal-oxygen interaction system, which can continuously afford reactive hydroxyl groups and further hydrogen free radicals for inactivating the active sites of coal oxidation by eliminating the crucial linking radicals (i.e. ROO•, RO•, •OH), cutting off the free radical chain reaction of coal oxidation and reducing the formation of secondary active sites, and as a result, realizing the continuous inhibition of coal spontaneous combustion [29]. On the basis of the sustained-release property of PAA/SA-CC, it can not only combine the inhibition characteristics of PAA/SA and CC, but also achieve synergism by improving the effective utilization rate as well as the inhibitory efficiency of CC.…”

“…This is ascribed to the high inhibiting efficiency of CC for its substantial capability on eliminating the crucial linking radicals (i.e. ROO•, RO•, •OH) of coal oxidation [29]. However, as the temperature rises, its defects of short active lifetime and low utilization are recognized for being depleted by the excess dynamic oxygen and losing the hydrogen-donating capacity prior to the coal oxidation system proceeding into the oxygen sorption-mass gain stage.…”

“…b The mass decrement in the case of the mass increase phenomenon disappearing. and hydroxyl radicals [29]. Therefore, the free radical chain reaction was cut off and further oxygen adsorption sites were eliminated, which chemically weakened the intrinsic reactivity of oxygen adsorption of coal, as a result, the tendency of coal proceeding to self-ignition was reduced.…”

Controlled-release inhibitor for preventing the spontaneous combustion of coal

“…Wang et al (2012a) investigated the inhibition effects of ionic liquids on coal self-heating and tried to propose a prevention method based on ionic liquids, which is expensive and hard to apply (Zhang et al 2013a(Zhang et al , 2013b. Dou and Wang et al (2014) analyzed the inhibition effects of some chemical compounds on the reaction of active groups .…”