Techno-economic and environmental assessment of polylactic acid production integrated with the sugarcane value chain

Abstract

In the global pursuit of sustainable production and cleaner consumption strategies, bio-based plastics have been increasingly developed, produced, and used in the field of renewable materials. This study performs techno-economic and environmental assessments of polylactic acid (PLA) produced via lactic acid from sugarcane juice fermentation in integration with a typical Brazilian ethanol distillery. PLA presents net negative GHG emissions: −0.25 kg CO 2 eq./kg PLA from cradle to factory gate. It shows lower environmental scores than traditional fossil-based plastics in global warming and fossil resource scarcity categories. However, it reveals the highest impacts in terrestrial acidification and land occupation due to sugarcane cultivation. PLA from this study also presents a smaller global warming potential in comparison to other PLA cited in the literature since the energy demand from all industrial stages is supplied by sugarcane bagasse and straw combustion. Production cost is estimated at US$ 1.41/kg PLA in a venture that reaches an Internal Rate of Return of 29.4 %. PLA's minimum selling price of US$ 1.58/kg is lower than the stipulated US$ 2.66/kg market price. The attractive environmental results coupled with this competitive economic performance show that the proposed route can contribute to sustainable production within the plastics sector.