ORIGINAL RESEARCH: The eco-profiles for current and near-future NatureWorks® polylactide (PLA) production

NatureWorks® polylactide (PLA) is a versatile polymer made entirely from annually renewable resources. Within the framework of sustainability, NatureWorks LLC is working to continuously improve the environmental performance of its product portfolio and is using life cycle assessment as a tool to identify and measure environmental performance-improvement objectives and to benchmark PLA against the petroleum-based polymers with which it competes in the marketplace. NatureWorks’ objectives include eliminating non-renewable energy use and the emissions of greenhouse gases (GHGs), as well as minimizing non-valuable co-products and reducing water use. These objectives are accomplished through continual improvement of the PLA production technology and utilization of renewable energy for process energy as much as possible. NatureWorks is purchasing wind power-derived renewable energy certificates (RECs) in an amount equal to the electricity used in the PLA production system in a commitment to utilize renewable energy wherever possible. The use of renewable wind energy certificates reduces the environmental burden associated with electricity use. The PLA production system in 2006 emitted 0.27 kg CO₂ eq./kg PLA and used 27.2 MJ/kg PLA of fossil energy—reductions of 85% and 50%, respectively, compared to 2003 PLA eco-profile data. In the near future, further improvement of the process technology, combined with the utilization of wind power for the process electricity requirements, will make NatureWorks PLA pellets a GHG sink. This paper provides the cradle-to-polymer-factory-gate life cycle inventory data (eco-profiles) for the 2006 and the near-future PLA production systems and explains the use of RECs.