Catalysis of sugarcane-bagasse pyrolysis by Co, Ni, and Cu single and mixed oxide nanocomposites

Pyrolysis of biomass is an important process in which renewable biological waste is converted to energy products and preliminary chemicals. Therefore, various types of catalysts, including metal oxides, have been investigated for more efficient and selective biomass pyrolysis. Co, Ni, and Cu single and mixed metal oxide (SMO and MMO) nanoparticles (NPs) of 3 to 47 nm were synthesized, characterized, and studies for their catalytic activities towards pyrolysis of sugarcane bagasse (PSCB). After mixing the oxide NPs with bagasse, thermogravimetry was performed at a heating rate of 5 °C/min from ambient temperature to 600 °C. Thermogravimetric analysis followed by kinetic calculations of the activation energy through Coats−Redfern model show that all oxide NPs of this study exhibit catalytic activity towards cellulose and hemicellulose thermal degradation during PSCB, in the order MMO > SMO. Cu-containing SMO and MMO NPs show exceptional catalytic activities compared to their analogues. On the other hand, lignin degradation kept proceeding over a wide range of high temperature, just like that of the plain PSCB. This is considered selective enhancement of the catalysis of cellulose and hemicellulose thermal degradation versus lignin degradation, which is promising for improving the composition and quality of PSCB products. Only Cu-containing double and triple MMOs were so catalytically active that they catalyzed lignin degradation along with the cellulose and hemicellulose.