Numerical and Experimental Investigation of Partial Oxidation of Methane over a Multiport Burner

Abstract

The demand for syngas is only increasing. Most syngas is produced via steam methane reforming (SMR), but there are several limitations to this process. Hence alternate methods for syngas production are desirable. Partial oxidation of methane (POX) has the potential to address some of these limitations. While this can be achieved catalytically, the thermal method avoids several complications. Since the conditions required for syngas production via POX are beyond the rich flammability limit of premixed methane, a diffusion configuration is studied. To ensure adequate mixing and control over the behaviour of the reaction, a multiport arrangement is examined, which maintains laminar flow conditions. The hot primary flame zone has been extensively examined, however limited investigation into the behaviour due to the multiport arrangement has been undertaken of the cooler, downstream secondary flame zone, the output of which produces the syngas used for subsequent processing. The system behaviour under syngas producing conditions was investigated numerically and experimentally. A 2D axisymmetric CFD model identified the main features of the flame. This led to the development of a chemical kinetics model which was successfully used to identify the system behaviour over a wide parameter space. Measurements of temperature and species were performed on a commercially-available burner. These data were used to validate the CFD model. The results from this preliminary study demonstrated that while the CFD model correctly predicted the experimental trends and temperature, there was some discrepancy in the magnitude of species concentrations, attributed to inaccuracies in the simulation of the mixing zone. This study has demonstrated that the multiport diffusion flame provides a stable basis for thermal POX of methane. Further work should be directed towards identifying optimal geometries and combustion conditions, such as velocity and compositions of the fuel and oxidant streams.