Life cycle assessment focusing on the waste management of conventional and bio-based garbage bags

Abstract

The development of bio-plastics significantly contributes to sustainable development in terms of the waste management aspects associated with lower environmental impact. To achieve the aim of this study the life cycle assessment (LCA) of garbage bags from cradle-to-grave is evaluated and compared. The materials to be studied in this paper are polyethylene (PE), biomass polyethylene from molasses (Bio-PE), and poly(butylene adipate-co-terephthalate)-starch blends (PBAT/starch). The functional unit defined for three types of garbage bags is 1 bag. The SimaPro LCA software 8.2.3 with the Eco-indicator 99 method for life cycle impact assessment (LCIA) is used to assess the environmental impacts. The normalized score from cradle-to-gate of almost all of the environmental impacts for the PE bag is lower than the scores for the Bio-PE and PBAT/starch bags, except for climate change and fossil fuels impacts, the Bio-PE and PBAT/starch bags have a small, normalized score for climate change impacts. The single score of PBAT/starch bags is 14.9% and 47.1% greater than the scores of PE and Bio-PE bags, respectively. The environmental impact performance from cradle-to-grave of the incineration of Bio-PE with energy recovery is better than the other options, in terms of fossil fuels. PBAT/starch bags also have the lowest normalized scores for climate change, and for respiratory inorganics impacts when the bags were composted. The single score values of the incineration of Bio-PE with energy recovery and PBAT/starch in composting are favourable for all of the options studied. The environmental impact reduction of bio-based bags could be achieved through low resource consumption techniques in the packaging and production stages, and through the ultimate utilization of Bio-PE as a waste-to-energy concept and PBAT/starch when converted to fertilizers for agricultural applications. © 2017