Environmental Impacts of Three Polyhydroxyalkanoate (PHA) Manufacturing Processes

This work investigates the environmental impacts of three manufacturing processes for a promising biodegradable polymeric material: polyhydroxyalkanoate (PHA). The processes studied are microbial PHA manufacturing using glucose as the carbon substrate, microbial PHA manufacturing using cheese whey as the carbon substrate, and microbial PHA manufacturing using genetically engineered plants. A lifecycle model is established for each of the processes, and the Eco-indicator 99 methodology is used in the study. Results with 10 indicators under human health, ecosystem quality, and resources are obtained and compared. Because the processes are still largely under development, many lifecycle data are rare and insufficient. A number of reference sources and reasonable assumptions are used in the calculations. The study has identified the major contributors to environmental impacts, and can quantitatively explain how each impact indicator is affected by a particular process. The study provides the information for technical decision-making for the development of environmentally-friendly PHA manufacturing processes.