Experimental and numerical study of syngas production during premixed and ultra-rich partial oxidation of methane in a porous reactor

Abstract

The synthesis gas (syngas) production from the ultra-rich methane/oxygen mixtures via the thermal partial oxidation in an inert porous reactor was investigated numerically and experimentally. Thermodynamic analysis was firstly conducted based on Gibbs free energy minimization method to find the possible optimum routes of operation. Then, the experiments were performed on the constructed test-rig with a non-catalytic porous based reformer. The flame is stabilized within zirconia (ZrO2) sponge, which has shown very high mechanical strength and thermal resistance. The main influencing parameters such as the equivalence ratio and thermal load have been investigated during different experiments. For this purpose, the reactor axial temperature profile and product compositions were determined experimentally. The obtained results reveal that the heat loss abatement; approaching to the adiabatic condition could effectively improve the amounts of syngas (H2+CO) production. The maximum syngas production was obtained 69.5% of the exhaust gas at the equivalence ratio of 2.5 and thermal load of 8 kW. Moreover, the H2/CO ratio was reported above 1.5, which can be suitable for feeding into other chemical processes. Finally, numerical simulation of the process was performed using the premixed and reactor network models. The contribution of heat loss from the reactor was also considered in the model due to its pivotal role observed in the experimental work. The average relative error of the reactor network model with respect to syngas generated from the reformer was found to be 6.72%. Therefore, the predictions obtained from this model are in fairly good agreement with the experimental data.