Greenhouse Gas Reduction Focused on Utilization and Treatment of Biomass-based Plastics in Household Waste

Yano, J.; Hirai, Y.; Sakai,S. (2011) Proceedings of 2011 World Congress of International Solid Waste Association (ISWA), pp. 301-311


This study estimated the GHG reduction effect of material conversion to biomass-based plastics using life cycle analysis. PLA and the compound of PBSA (70%) with PLA (30%) were focused on as biomass-based materials. 8 groups of plastic packaging and container in household waste were focused and conversion ratios were set in each group. "The treatment of 1 m3 of waste plastic packaging and container disposed from household and their production" was considered as the functional unit. The result indicated that GHG emissions in direct landfill were increased by the conversion to biomass-based material because of biodegradation. Therefore landfill of biomass-based plastics should be avoided. Some properties of biomass-based plastic, lower LHV and higher density, had a significant impact on GHG emission. The increased amount of GHG emission in pellet production by material conversion had an effect on all the treatment method and cancelled out the benefits of all the recycling methods. This increase was also due to the way of setting the functional unit. However, conversion to biomass-based material could reduce GHG emission slightly. The existing recycling system of plastic waste was focused on in this analysis. However, these recycling methods were intended to treat fossil-derived plastic. The development of original utilizing and recycling methods for biomass-based plastic was important.