Optimizing Operating Conditions for Oxidative Coupling Methane (OCM) in the Presence of NaCl-MnOx/SiO2

Abstract

A novel NaCl-MnOx/SiO2, synthesized using slurry mixed method, was used as a catalyst in oxidative coupling of methane process. Optimal conditions were determined using both computational and experimental methods. NaCl, MnOx and SiO2 which are the component of our catalyst are studied. In this research, the catalyst provided the best experimental result when the ratio of MnOx to SiO2 was 2 to 1. CH4 conversion, C2+ selectivity, C2+ yield and C2H4/C2H6 ratio were achieved at 38%, 71%, 27% and 7.2, respectively when operated the process at optimal temperature of 750°C under atmospheric pressure with ratio of CH4:O2 at 4 and 3000 mL g–1 h–1 of weight hourly space velocity (WHSV). The catalytic performance of NaCl-MnOx/SiO2, was found to be higher than other recently developed catalysts. Besides, NaCl-MnOx/SiO2 gave only less than 10% selectivity of the unwanted CO2, while the other SiO2-based catalysts reported as high as 17% of CO2 selectivity. It also achieved high ethylene production when benchmark with previous research. The experimental results were validated using Aspen Plus at temperature ranging from 700 to 850°C.