12 / 2023-05-12 08:26:37

Research on the Key Technologies of Large Scale Reactor Used for Ultra-Low Concentration Methane Co-Oxidations

Ultra-Low Concentration Methane,Porous media Oxidation,Honeycomb ceramic,Foam ceramic,Granular bed

This study proposes a method of using coal mine low-concentration extracted gas to assist in VAM mitigation. A large-scale combustion plant model for coal mine low-concentration extracted gas utilization with synergistic VAM mitigation was constructed based on the volume-averaging method. The pressure loss and heat transfer models of the honeycomb monolith bed were developed by referring to the mechanism of the fully development of laminar flow in the channels. The combustion plant is divided into six independent combustion chambers. Through parameterization research, the length and elevation angle of the guide plate arranged at the front end of each chamber are determined to ensure consistent inlet volume flow rate of each combustion chamber. The effect of the layout of pipe for VAM inside the device on the combustion characteristics, as well as the effect of VAM flow rate and concentration on methane elimination efficiency was studied. The results show that reducing the diameter of the VAM inlet pipe, the diameter of the VAM inlet pipe side holes, and shortening the spacing between the VAM inlet pipe side holes can improve the mixing degree of the VAM and the upstream high-temperature flue gas, thereby improving the VAM mitigation. When the ratio of low concentration extraction gas inlet volume flow rate to VAM inlet volume flow rate, it is basically possible to achieve near-zero methane emission from the outlet of the plant at ventilation air methane concentrations as low as 0.1%. As the VAM inlet volume flow rate increases, the methane concentration decreases, and the methane elimination efficiency tends to decrease after reaching the upper limit of the VAM treatment. The utilization of low concentration gas extraction in conjunction with VAM oxidation offers a solution to the issues of conventional thermal flow reversal treatment of VAM due to the influence of ventilation air methane concentration and unstable device operation.