Sustainable Food Waste Management: Synthesizing Engineered Biochar for CO2 Capture

Humanity needs innovative ways to combat the environmental burden caused by food waste, which is one of the critical global issues. We proposed food waste-derived engineered biochar (FWDEB) for CO2 capture from a life cycle perspective. FWDEB samples were prepared by carbonization and chemical activation for CO2 adsorption. FW400-KOH600(2), carbonized at 400 °C and then activated at 600 °C with a KOH/biochar mass ratio of 2, presented the best CO2 adsorption capacities of 4.06 mmol g–1 at 0 °C (1 bar) and 2.54 mmol g–1 at 25 °C (1 bar) among all prepared samples. The CO2 uptake at 25 °C (1 bar) was affected by both micropore volume and surface area limited by narrow micropores less than 8 Å. Basic O- and N-functional groups were generated during the KOH activation, which are beneficial for enhancing the FWDEB-based CO2 adsorption. Moreover, a life cycle assessment was implemented to quantify the potential environmental impacts of FW400-KOH600(2), indicating that negative net global warming potential could be achieved using the FWDEB-based CO2 capture approach. Owing to the environmental benefits, we highlighted its potential as a promising technical route to mitigate climate change and achieve a waste-to-resource strategy.