Oxidative coupling assisted methane aromatization — a simulation study

This study simulates a high-temperature reaction in a plug-flow reactor (PFR) for the aromatization of methane via oxidative coupling of methane (OCM) using a state-of-the-art gas-phase chemical kinetic mechanism. Benzene is formed from a methane-oxygen (CH4–O2) feed via formation of ethylene through OCM followed by homogeneous gas-phase aromatization of C2H4 after O2 depletion. Because both OCM and C2H4 aromatization are exothermic reactions, the process is advantageous over an endothermic non-oxidative methane aromatization reaction. For the OCM reaction, the previously reported mechanism in which the catalyst achieves the quasi-equilibrated formation of OH· from an H2O–O2 mixture was included in the combustion chemistry network. It was evident that OH· formation increased benzene yield as a consequence of enhanced C2H4 yield from the OCM. The influence of temperature and contact time on benzene yield was elucidated, and reaction pathways leading to aromatic formation were analyzed. The maximum benzene ...