Carbon footprint and energy requirement of the biopolymers polyhydroxyalkanoates: a review

Polyhydroxyalkanoates (PHAs) are naturally occurring biopolymers, obtained from microorganisms. Through LCA it is possible to account for all the environmental impacts associated with PHAs. The review analysis is based on 28 LCA studies for PHAs and PHB. In this study, first of all a review analysis of published LCA studies for PHAs production using different approaches was performed, showing that both the choice of feedstock and the use of process residues and co-products for energy production can lower the environmental impacts of the production process. Moreover, the downstream process for the extraction of biopolymer grains usually has the highest influence on results. Climate change impact values generally are between 1 and 6 kilos of CO2-eq. per kilo of PHA produced, whereas in most studies the energy requirement is higher than 50 MJ per kilo of biopolymer.