Linking physicochemical properties to combustion performance: Effects of torrefaction and briquetting on sugarcane bagasse

The growing recognition of biomass as a key renewable energy source has shifted the focus from its availability to improving its conversion efficiency and enabling large-scale application. In this context, understanding how thermochemical pretreatments influence combustion behavior is essential. However, limited studies have evaluated the combustion performance of torrefied and densified biomass under conditions representative of practical applications, rather than relying solely on thermogravimetric analyses. This study investigated the combined effects of torrefaction and briquetting on the physicochemical properties and combustion performance of sugarcane bagasse. Torrefaction was conducted at different temperatures, followed by densification and comprehensive material characterization. Thermogravimetric analysis and bench-scale combustion tests were performed to assess combustion behavior and performance indicators. Pearson correlation analysis was conducted to evaluate the relationships between chemical and physical properties. The results showed that torrefaction progressively increased the fuel ratio, indicating enhanced carbonization; however, the fuel ratio improvement did not directly translate into better combustion performance. Instead, the highest combustion performance, as indicated by the combustion index, was achieved under mild torrefaction conditions. Furthermore, samples subjected to higher torrefaction temperatures exhibited reduced structural integrity, leading to faster but less stable combustion behavior after densification. Overall, the findings demonstrate that better combustion performance in densified torrefied biomass is not achieved at the highest torrefaction temperature, but within a range where a balance between chemical upgrading and physical structure is maintained. • Higher carbonization alone did not ensure better combustion performance. • Severe torrefaction reduced briquette density and combustion performance. • Mild torrefaction (200–225 °C) improved combustion efficiency after densification. • Fuel performance depended on balancing chemical and physical properties. • Structural integrity was essential for efficient briquette combustion.