Research on Low-Oxygen Air Displacement Technology for Gas Drainage Boreholes

This paper addresses the issues of low efficiency and high safety risks in coal seam gas extraction by proposing a gas extraction technology based on low-oxygen air displacement. Oxygen content below 8% was prepared by membrane separation, pressure swing adsorption, and oxygen-absorbing and oxygen-releasing agent technology. The ratio of oxygen-absorbing and oxygen-releasing agents was optimized through orthogonal experiments, and the effects of cobalt oxide (CoO), ferrous oxide (FeO), and additives on oxygen consumption were analyzed. The research shows that cobalt oxide contributes the most to the oxygen reduction effect, and the optimal material ratio is cobalt oxide: ferrous oxide: additive = 4:2:1, which can significantly reduce the oxygen content of the injected gas and achieve recycling. The low-oxygen air displacement technology enhances the desorption efficiency of methane through gas displacement, eliminates the risk of gas explosion, and reduces equipment corrosion. This technology provides a new method for the safe and efficient extraction of gas from low-permeability coal seams, with both engineering practicality and environmental safety.