Direct conversion of methane in formaldehyde at very short residence time

To obtain new kinetic data, a quartz annular flow microreactor was chosen for the experimental investigation of the gas phase partial methane oxidation to formaldehyde under high temperature (1173–1273 K) and short residence time (20–60 ms). High formaldehyde selectivity (up to 80%) is achieved, but the yield remains low. For a single pass operation, the best HCHO experimental yield is 2.4%. The kinetic simulation using GRI-Mech 3.0 shows an overall good agreement with the experimental data, though there does exist some discrepancies for some conditions. The general pathways of the reaction show that HCHO is formed mainly from direct oxidation of methyl radical CH3 by O2, and partly from dehydrogenation or oxidation of methoxy radical CH3O.