A Study of Methane Hydrate Combustion Phenomenon Using a Cylindrical Porous Burner

Direct hydrate combustion usually leads to unstable flame and flame extinction due to the "self-preservation" phenomenon. A novel cylindrical porous burner to maintain a stable methane hydrate flame for further experimental investigation is proposed and developed in this study. The characteristic flame patterns, flame structure, and reaction pathway of methane hydrate flame are studied using experimental and numerical methods. The proposed burner can effectively solve the burning issues and sustain a stable flame. The methane hydrate flame is characterized as a methane flame with a high percentage of water vapor addition in the stream. Furthermore, the chemical effects of high percentage of water vapor addition on the reaction pathway of premixed CH4/air flame are numerically investigated and the results show that the enhanced OH radical production through water decomposition (R86) promotes progressive dehydrogenations of CH4 to CH3, CH3 to CH2(s), and CH2O to HCO, and finally oxidation of CO to CO2, providing additional pathways for methane oxidation reaction.