Production of Biofuel by Pyrolysis of Sugarcane Bagasse and Cassava Rhizome in a Free Fall Reactor: Experimental and Modelling Approaches

Abstract

Agricultural residues are being explored as sustainable energy sources to mitigate global warming and reduce greenhouse gas emissions. This study investigates biofuel production from a free-fall reactor using sugarcane bagasse (SCB) and cassava rhizome (CR) as feedstocks, employing both experimental and modelling approaches. Pyrolysis was conducted with varying SCB-CR blend ratios, from 400 to 650 °C, with a 30 min residence time, to analyse yields of biochar, bio-oil and biogas. Ultimate and proximate analyses were performed on feedstocks and biofuels, to determine their properties. Mathematical models for biofuel yields were developed using multi-expression programming (MEP), and validated against multilinear regression (MLR). Optimal 50:50 SCB-CR composition produced the highest bio-oil yield of 36.2%, with a heating value of 23.6 MJ/kg, at 550 °C, alongside with 16.2% biochar and 47.6% biogas. MEP models demonstrated superior accuracy, with R² values of 0.974, 0.917 and 0.774, for biochar, bio-oil and biogas, respectively, outperforming MLR models. Results indicate that copyrolysis of SCB and CR enhanced biofuel yield and quality, due to synergistic effects. Integration of experimental data with modelling provides a pathway in optimizing process parameters for large-scale biofuel production.