272 / 2018-04-19 08:56:40

Sustained elimination of coal-mine gas with ZnO/AC composites based on adsorption-photodegradation coupling effects

coal-mine gas,gas controlling,adsorption,chemical oxidation,synergistic effect

矿井瓦斯与煤与瓦斯突出 > 煤矿瓦斯

The accident caused by gas exceeding the limit is one of the worst disasters in coal mine. As the main component of coal-mine gas, methane is chemically stable and cannot be eliminated effectively by conventional methods, however, photochemical reaction is the primary dissipation way of methane in the atmosphere. In the present study, the methane elimination experiments with simulated coal-mine gas have been carried out over adsorption-type composite catalysts (ZnO/AC) in self-designed fixed-bed reactor under ultraviolet irradiation. The effects of AC mass ratio, methane concentration, and irradiation intensity on methane elimination efficiency are investigated, respectively. The results indicate that for the gas containing 1.5% methane, about 80% methane can be eliminated continuously in 75 min over the prepared ZnO/AC composites. The introduction of coal-based activated carbon (AC) facilitates the dispersion of ZnO nanoparticles and enhances the adsorption of methane molecules. The zinc ions of ZnO play an important role in methane activation. The interface created between AC and ZnO phase facilitates the adsorption of CH4 onto AC and the transfer of adsorbed CH4 to catalytic active component ZnO. The synergistic effects of AC and ZnO give rise to efficient and sustained methane eliminate performance. This study provides a new idea for the gas controlling in local region of coal mine using adsorption-photocatalytic coupling technology.