Reaction coupled with transport phenomena in oxidative coupling of methane:CFD modeling for single pellet

Abstract

This study presents the phenomena occuring in small scale single-pellet for the oxidative coupling of methane where heat transfer plays an important role. Computational fluid dynamics (CFD) is used as a tool for obtaining detailed rate and temperature profiles through the porous catalytic pellet where reaction and diffusion are competing. Inter particle temperature and concentration gradients were taken into account by solving heat transfer coupled with continuity equations in the catalyst pellet. In the heat transfer equation the source term of energy due to high exothermic of reaction is considered. Subsequent to achieving this goal, two external programs are successfully implemented to CFD-code as kinetic and heat of reaction terms. This simulation results show the reaction is favorite for the beginning of the pellet and for downstream of the pellet domain the diffusion is predominates. The results of CFD simulation indicate that temperature variation within the catalyst pellet is < 1K due to the completion of exothermic oxidation reactions. Also, the results show that exothermic oxidation reactions occur before endothermic coupling reaction in the pellet length.

Keywords

• catalyst pellet
• oxidative coupling of methane
• modeling
• cfd
• kinetics