Transport Control in a Microwave Plasma Reactor to Enhance Ethylene Selectivity in Methane Coupling

ABSTRACT

The chemical kinetics of thermal methane coupling indicate that residence time strongly influences product distribution, with shorter residence times favouring ethylene over more dehydrogenated products. In this work, methane coupling is investigated in a microwave plasma reactor using forward and reverse vortex flow configurations to modify transport through the plasma region. Forward vortex results in product distributions consistent with longer residence times and higher temperatures, characterised by high acetylene and deposits yields. Reverse vortex configuration is implemented to increase axial velocity in the plasma core, enhancing ethylene selectivity and suppressing carbon deposition on the reactor walls. This work demonstrates the importance of flow topology for plasma reactor engineering and how flow vorticity impacts chemical kinetics via flow stagnation and recirculation.