Experimental demonstration and modeling of an adsorption-enhanced reverse flow reactor for the catalytic combustion of coal mine ventilation air methane

• Modification of catalytic reverse flow reactor for the treatment of humid emissions.
• Reactor ends contain a water adsorbent (alumina).
• This reactor equally performs for dry and humid emissions.
• Experimentally validated reactor model (considering both catalyst and adsorbent).

Ventilation air methane is a major contributor to the carbon footprint of the coal mining industry. This contribution can be mitigated by combustion of methane to carbon dioxide. The use of efficient combustion devices, such as catalytic reverse flow reactors, can improve the economy of the process. However, the high water content of the ventilation air can inhibit catalysts (such as palladium) used in this process. The overcome this issue a novel reverse flow reactor with integrated separation, capable of adsorbing water from the feed before reaching the catalyst, is studied. The adsorbent is regenerated in situ thanks to the characteristic thermal pattern of reverse flow reactors. The application of this reactor design to the combustion of ventilation air methane has been demonstrated in a bench-scale device, operated at 0.15 m/s (n.t.p.) superficial velocity and different methane concentrations (1800–5400 ppm) and switching times (100–600 s). A mathematical model for this reactor has been proposed, the water adsorption parameters have been determined experimentally, and the model has been validated by comparison to bench-scale experimental results.

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