Catalytic co-pyrolysis of macroalgal components with lignocellulosic biomass for enhanced biofuels and high-valued chemicals

This study focuses on catalytic co-pyrolysis of a lignocellulosic biomass (rice husk) and main components of the seaweed Enteromorpha clathrata (ie, protein, polysaccharide, and ash) using TGA and Py-GC/MS analytical techniques with the aim and novelty to unveil their catalytic co-pyrolysis thermal behaviors and synergistic effect of interactions between their catalytic co-pyrolysis volatiles for enhanced biofuels and high-valued chemicals production. Thus, in this study, rice husk was treated with macroalgal major components over ZSM-5, MCM-41, and blend of both catalysts using the Py-GC/MS analytical technique to improve the quality of rice husk bio-oil. Thermogravimetric analysis studies of pyrolysis, co-pyrolysis, and catalytic co-pyrolysis of lignocellulosic biomass with seaweed main components were also performed. Effects of HZSM-5, MCM-41, and blend of both catalysts on catalytic co-pyrolysis products distributions were also studied and compared. Results revealed that the quality and chemical compositions of rice husk bio-oil were significantly improved owing to the synergistic effect of interactions between volatiles of rice husk and seaweed main components during catalytic co-pyrolysis. Also, catalytic co-pyrolysis of macroalgal components and lignocellulosic biomass with ZSM-5, MCM-41, and blends of both catalysts were found to considerably reduce the oxygenated compounds, and greatly improved selectivity of monocyclic aromatic hydrocarbons in the bio-oil. However, MCM-41 offered a stronger positive upgrading effect than ZSM-5 catalyst. This could be attributed to its greater ability in raising the selectivity of aromatic hydrocarbons and reduction of activation energies of the degradation reactions. It was also observed that blends of both catalysts offered a higher upgrading effect than ZSM-5 and MCM-41 catalysts alone. Novelty Statement Catalytic c-pyrolysis of macroalgal components and lignocellulosic biomass with ZSM-5, MCM-41, and blends of these catalysts greatly improved selectivity of monocyclic aromatic hydrocarbons in the bio-oil. MCM-41 offered a stronger positive upgrading effect than ZSM-5 in raising the selectivity of aromatic hydrocarbons and reduction of activation energies. Blends of both catalysts offered a higher upgrading effect than ZSM-5 and MCM-41 catalysts alone. Highlights Catalytic co-pyrolysis of lignocellulosic biomass with major macroalgal components was performed. Synergistic effect of catalytic co-pyrolysis of lignocellulosic biomass & macroalgal components were unveiled. Effect of HZSM-5 & MCM-41 catalysts on product distributions were studied & compared. Thermal behaviors and mass loss characteristics of degradation processes were unveiled.