使用済み自動車からの板ガラスリサイクルの環境性および事業採算性評価

Abstract

Objective. Recycling of glass from end-of-life vehicles (ELV) has been of interest since the enforcement of Law on Recycling of End-of-Life-Vehicles. The objective of this work is to investigate the environmental and economic aspects of the recycling system of glass sheets from ELV. Life cycle inventory analysis was conducted to analyze the reduction potential of CO2 emissions by recycling the grass sheets from ELV. Cash flow analysis (CFA) was applied to the recycling system, in which internal rate of return, IRR, was used as an index of the economic feasibility. Sensitivity analyses were conducted to investigate the effect of the transport distances of collected glass sheets from ELV on CO2 emissions and IRR, respectively.Results and Discussion. It was found that the reduction potential of CO2 emissions by recycling the grass sheets from ELV was 17 kg-CO2/ELV, which was mainly attributable to the reduction of CO2 emissions in production of glass sheet by the use of glass cullet and by avoidance of the treatment of automobile shredder residue (ASR). From the results of MFA by the authors reported in the previous paper, this result would be valid as long as the amount of glass cullet recovered from ELV would not exceed to 124 thousand t/year. CFA showed that the amount of inverse onerous contract, loading ratio of truck transport and collection area of glass sheets from ELV had significant effect on IRR. Conclusions. This work has proved that there is a certain reduction potential of CO2 emissions by recycling glass from ELV. The economical feasibility is significantly dependent on the amount of inverse onerous contract, loading ratio of truck transport, collection area, and prices of recovered materials, so it is recommended that stakeholders should discuss how to manage the recycling glass from ELV. This case study also shows integration of LCA, MFA and CFA is very effective when we assess environmental and economic aspects of recycling materials from end-of-life products.