Mohammad Haghighi - Chemical Engineering Department, Sahand University of Technology GPO Box ۵۱۳۳۵-۱۹۹۶, Sahand New Town, East Azarbaijan, Iran
Dong-ke Zhang - Centre for Fuels and Energy, Curtin University of Technology GPO Box U۱۹۸۷, Perth WA ۶۸۴۵, Australia

Due to the increasing importance of remote gas utilisation as well as gas to chemicals rather than gas to energy, methane to C2-hydrocarbons can be one of the potential means in natural gas economy. In order to identify the effect of operating conditions on this process, Gibbs free energy changes as well as thermodynamic equilibrium aspects of the reaction system have been analysed. The Gibbs free energy minimisation method was used to calculate thermodynamic equilibrium using the CHEMKIN software. It was found that CO2 and H2O are the dominant components in the product at temperatures less than 1000 K, while reforming products, CO and H2, are the major compounds at high temperatures. At low temperatures the selectivity of ethylene, the most useful component in C2-hydrocarbons, is less than that of ethane, while at higher temperatures it can compete with ethane production. It was found that pressure plays a negative role in methane conversion and C2H2 and C2H4 selectivities, while C2H6 selectivity is enhanced with increasing pressure. It was shown that C2-hydrocarbons production increases while methane conversion decreases with increasing CH4/O2 ratio. The addition of nitric oxide did not have a significant effect on this process.

C2-Hydrocarbons, Methane partial oxidation, Methane coupling