Life-cycle and techno-economic analyses of agro-waste-derived biodegradable plastics enhanced via AI-based parametric optimization

초록

Growing concerns over climate change and the environmental impact of the overuse of petrochemical-based plastics have prompted the adoption of eco-friendly alternatives. Here, a starch-based biodegradable plastic sheet was synthesized from underexploited agricultural waste (sago and jackfruit starches) and plasticized with glycerol and sorbitol using acetic acid as a moderate cross-linking agent. Operating parameters for high output were adjusted using a response surface approach and an artificial neural network model, exhibiting high prediction accuracies (R2 = 0.980 and 0.991, respectively). The optimal combination included 5 g sago starch, 5 g jackfruit starch, 1.25 g glycerol, 1.25 g sorbitol, and 0.75 mL acetic acid to achieve 1.659 ± 0.03 MPa tensile strength, an elongation at break of 63.18%, and 104.26 MPa Young's modulus. Extensive solvent-resistance tests confirmed the film's strength, and 80% of the film degraded after 10 days of burial in soil. Life-cycle assessment showed that producing 1 tonne of starch-based biodegradable film resulted in a climate change impact of 1220 kg CO2eq, mainly caused by the use of additives and the high energy demand during various unit operations. Techno-economic evaluations predicted a minimum selling price of USD 1.67/kg, confirming cost-competitiveness with conventional fossil-based polymers and substantially lower costs than polylactic acid and polyhydroxyalkanoate alternatives. Life-cycle and techno-economic analyses suggest that starch-based bioplastics made from agro-waste have a positive environmental impact and show potential for scalable production, supporting their application in packaging and other low-load uses.

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