The greenhouse gas emissions and fossil energy requirement of bioplastics from cradle to gate of a biomass refinery

Abstract

Polyhydroxyalkanoates (PHA) are promising eco-friendly bioplastics that can be produced from cellulosic ethanol biorefineries as value-added coproducts. A cradle-to-factory-gate life cycle assessment is performed with two important categories: the greenhouse gas (GHG)emissions and fossil energy requirement per kg of bioplastics produced. The analysis indicates that PHA bioplastics contribute clearly to the goal of mitigating GHG emissions with only 0.49 kg CO(2-e) being emitted from production of 1 kg of resin. Compared with 2-3 kg CO(2-e) of petrochemical counterparts, it is about 80% reduction of the global warming potential. The fossil energy requirement per kg of bioplastics is 44 MJ, lowerthan those of petrochemical counterparts (78-88 MJ/kg resin). About 62% of fossil energy is used for processing utilities and wastewater treatment, and the rest is required for raw materials in different life cycle stages.