Jun Nakatani 교수

The Japanese government developed a strategy for plastics and laid out ambitious targets including the reduction of 25% for single-use plastic waste and the reuse/recycling of 60% for plastic containers and packaging by 2030. However, the current usage situation of single-use plastics including containers and packaging, which should be a basis of the strategy, is unclear. Here, we identify the nationwide material flow of plastics in Japan based on input-output tables. Of the domestic plastic dem

A mathematical framework of the life cycle inventory (LCI) analysis in life cycle assessment (LCA) of recycling is systematically reviewed with the aid of graphical interpretation. First, the zero burden approach, which has been applied to LCI analyses of waste management systems, is theoretically justified in terms of relative comparison of waste management options. As recycling is a multi-functional system including the dual functions of waste management and secondary material production, the

In Japan, the material recycling (MR) of plastic packaging waste faces several problems. Almost half of the collected waste plastics become residue, and the quality of recycled resins is not high because the mixture of various types of plastics makes sorting by resin type difficult. Therefore, an appropriate combination of source separation targets and sorting processes based on plastic type needs to be explored to increase the quantity of waste plastics recycled and enhance the quality of recov

Municipal solid waste management (MSWM) systems in developing countries adopt practices from developed countries to reduce their environmental burdens. However, several complex issues specific to developing countries hinder the full implementation of these practices. The future of MSWM in Davao City, Philippines, is envisaged as a notable example of the combination of new infrastructure and local MSWM practices. A linear programming model was developed, following material flow analysis and life

• A market share-based model to evaluate avoided burdens by recycling was formulated. • Effect of future decarbonization in the industry on climate benefits was analyzed. • The model was applied to recycling/recovery options of plastic packaging waste. • Impact of energy recovery on climate change was markedly increased in the model. • Climate benefits of gasification would decrease as industries are decarbonized. In the life cycle assessment (LCA) of recycling, the estimation of avoided burdens

The environmental impact of the existing and improved management systems of the estimated current and future generation of construction and demolition waste (CDW) in Metro Manila, the Philippines, was evaluated in terms of global warming potential (GWP) and urban land occupation (ULOP). CDW generation quantities were estimated using dynamic material flow analysis, and the environmental impacts of different CDW management systems were evaluated based on life cycle assessment using the ReCiPe midp

Focusing on plastic packaging waste, this study aimed to design feedstock recycling scenarios by harnessing industrial processes in a region and to specify the technological requirements to obtain climate benefits. The amount and resin composition of plastic packaging waste that could be collected from the region surrounding an oil refinery and sorted using different sorting schemes were projected. A pyrolysis experiment using samples tailored to mimic the projected composition and distillation

Abstract Japan implemented mandatory charging for single-use plastic shopping bags in 2020. In this study, we verified the policy effect and its persistence by analyzing the changes in the number of plastic shopping bags taken and discarded by consumers before and after the charging came into effect. Online surveys were conducted in 2016, 2021, 2022, and 2023 for consumers residing in municipalities in Tokyo. The results showed that the number of plastic shopping bags taken decreased to approxim

Identification of environmental hotspots becomes a pressing issue for companies pursuing sustainable supply chain management. In particular, excessive dependence on water resources outside the country may put the supply chain at unanticipated risk of water shortage. This article presents a practical approach to screening potential environmental hotspots of different impact categories that occur in the supply chain using environmental input-output analysis. First, the amounts of domestic and fore