Comparative study of the two-zone fluidized-bed reactor and the fluidized-bed reactor for oxidative coupling of methane over Mn/Na2WO4/SiO2 catalyst

In this work, oxidative coupling of methane over Mn/Na₂WO₄/SiO₂ catalyst is studied in a two-zone fluidized-bed reactor (TZFBR) and its performance is compared with a fluidized-bed reactor (FBR). Diluted oxygen in argon was introduced into the bottom of the TZFBR through a quartz ferrite and methane was entered at higher positions along the fluidized bed. The catalyst circulated between the oxygen-rich and methane-rich zones in the TZFBR reactor. The effects of the main operating variables including bed temperature, the methane/oxygen ratio (R_mo), and the height at which methane was introduced into the reactor (H_m) were investigated. It is found that under some operating conditions the TZFBR gives a higher C₂ selectivity than that obtained in the FBR reactor. Reaction of methane with lattice oxygen of the Mn/Na₂WO₄/SiO₂ redox catalyst in the methane-rich zone may have led to the higher selectivity.