Vol. 11, Issue 2 (2022)

Author(s):
V Karuppasamy Vikraman, P Subramanian, S Sriramajayam, R Mahendiran and S Ganapathy

Abstract:
The thermal degradation behaviour of monometallic (Co and Fe) and bimetallic catalysts (Co:Fe) for Fischer-Tropsch synthesis were studied using a thermogravimetric analyser. The catalysts were synthesized by impregnation technique with activated carbon as support. The monometallic catalyst 20Co/AC showed four stages of thermal decomposition in the temperature range of 30-274 °C. While the monometallic catalyst 20Fe/AC exhibited three stages of thermal decomposition in the temperature range of 30-350 °C. Multiple weight loss peaks for the bimetallic catalyst 18Co2Fe/AC indicated the sequential conversion of metal nitrates into oxides. The bimetallic catalysts 15Co5Fe/AC and 10Co10Fe/AC exhibited broad peaks with a shoulder implying the parallel conversion of cobalt and iron nitrates into their corresponding oxides. Both the monometallic and bimetallic catalysts showed no significant weight loss above 350 °C. Hence, the catalysts can be heat treated at 350 °C for the conversion of metal salts into oxides. The present study recommends the thermogravimetric analysis as a technique to discern the thermal degradation behaviour and to determine the heat treatment temperature of the catalyst used for Fischer-Tropsch synthesis.