Multi-bed type oxidation reactor applied to the coal mine ventilation air methane

The utilization of coal mine ventilation air methane plays an important role in saving energy, reducing pollution, improving the safety in coal mine production, and adjusting the energy structure. The thermal flow-reversal reactor is one of the main technologies of ventilation air methane utilization which is at a critical stage of industrial application. The thermal flow-reversal reactor of MEGTEC company and those designed by some Chinese scholars generally use a two-bed type. The gas that is detained in the oxidation chamber and reversal valves will not enter the combustion chamber, but through the chimney directly into the atmosphere when switching the flow direction, the average oxidation rate of the reactor will be reduced due to the residual gas. In order to solve the problems including low oxidation rate of methane, pressure build-up of the main fan, and high failure rate of valves in existing two-bed type oxidation reactor of coal mine ventilation air methane, an innovative structure with multi-bed type oxidation reactor has been designed. The paper analyzes the unique advantages of the multi-bed type oxidation reactor by elaborating on the working principles of three-bed and five-bed type device. In the design of the oxidation device for industrial demonstration projects, the device whose processing capacity is 100,000 m(3)/h adopts the five-bed type structure from the aspects of methane oxidation rate, waste heat utilization effect, cost, etc. The thermodynamic calculation process of regenerative chambers as the core unit of the oxidation device is described in this paper. The technology has an industrial demonstration project whose reactor uses a five-bed type design located in Chongqing Songzao Datong No. 1 mine. This project can produce 64800 t of superheated steam and reduce emissions of CO2 equivalent to 107000 t annually, and therefore has excellent energy-saving and emission reduction benefits.