Researchers at the Hawaii Natural Energy Institute, University of Hawaii at Manoa have calculated that the production of polyhydroxyalkanoates (PHA) as a value-added byproduct from cellulosic ethanol biorefineries results in GHG emissions (CO2e) of 0.49 kg per 1 kg of resin on a full lifecycle basis. This compares to 2-3 kg CO2e for petrochemical counterparts—a reduction of between 76-84%.
The fossil energy requirement per kg of bioplastics is 44 MJ/kg resin, lower than 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.
The team of Jian Yu and Lilian X. L. Chen published a paper on their work online 16 August in the journal Environmental Science & Technology.
Jian Yu and Lilian X. L. Chen (2008) The Greenhouse Gas Emissions and Fossil Energy Requirement of Bioplastics from Cradle to Gate of a Biomass Refinery. ASAP Environ. Sci. Technol., doi: 10.1021/es7032235