Transforming supermarket food waste to resource: A sustainability assessment of biochar conversion using carbon footprint and life cycle cost analyses

This study analyzed categories and quantity SFW generation from a supermarket in Thailand. Supermarket food waste (SFW) from a supermarket in Bangkok was collected, classified, and analyzed. This study assessed the carbon footprint (CF) and life cycle cost (LCC) of four management scenarios: landfilling, energy-recovery incineration, and biochar conversions for utilization as alternative fuel and soil amendment—using a functional unit of one tonne of generated SFW. CF was calculated using the IPCC 2013 LCIA method, while LCC included investment, operation, and maintenance costs. The results revealed that Fruits and vegetables (67.91%) were predominant in SFW, highlighting its suitability for organic waste conversion, while plastics (78.69%) constituted the majority of supermarket packaging waste (SPW), highlighting potential for segregation and material recovery. Landfilling imposed the highest environmental and economic burdens, with CF of 622.31 kgCO 2 eq and LCC of 66.64 USD. Energy-recovery incineration produced CF of 273.57 kgCO 2 eq and LCC benefit of -25.27 USD. Biochar conversion as alternative fuel resulted in avoided CF of -57.53 kgCO 2 eq and LCC of 33.51 USD, while biochar as soil amendment provided the greatest avoided CF of -560.33 kgCO 2 eq but incurred LCC of 54.71 USD. These results highlight the environmental benefits of SFW biochar conversion, particularly for soil amendment application, though economic performance must be improved to enhance competitiveness. • Fruits and vegetables was the majority among supermarket food waste (67.91%). • Energy-recovery incineration offered financial benefits. • SFW biochar utilizations offered environmental benefits.