Life Cycle Assessment of Laboratory-Scale Sugarcane Bagasse-Derived Activated Carbon

Agricultural residues such as sugarcane bagasse have been explored as renewable precursors for activated carbon production. However, the environmental performance of activated carbon can be strongly influenced by energy-intensive thermal processing, chemical activation, and the functional unit used for interpretation. While several life cycle assessment studies have been reported for sugarcane bagasse-derived activated carbon, many rely on secondary data or focus primarily on production-stage impacts without incorporating adsorption performance. This study evaluates the environmental performance of laboratory-scale sugarcane bagasse-derived activated carbon produced using a process-based life cycle assessment under laboratory-scale conditions. The system boundary includes feedstock preparation, thermal conversion (pyrolysis), chemical activation, and post-treatment steps such as washing and neutralization. Under the product-based functional unit, climate change impacts were 5.11 and 4.89 kg carbon dioxide equivalent per kg activated carbon for potassium hydroxide and sodium hydroxide activation, respectively, while net energy demand was 115 and 110 MJ per kg activated carbon. Contribution analysis identified pyrolysis electricity as the dominant hotspot for climate change and energy demand, whereas chemical activation influenced toxicity- and resource-related categories. When adsorption performance was considered, potassium hydroxide activation showed improved results for selected indicators because of its higher methylene blue adsorption capacity; however, resource-related burdens remained higher than sodium hydroxide activation. Overall, the study demonstrates that laboratory-scale activated carbon assessments require cautious interpretation and that integrating adsorption performance with life cycle metrics provides a more decision-relevant basis for comparing biomass-derived adsorbents.