Application of energy and CO2 reduction assessments for end-of-life vehicles recycling in Japan

Abstract

The transportation sector constitutes approximately 25% of the total energy consumption and CO2 emissions worldwide. Therefore, in the last decades, several studies have been conducted to improve the energy efficiency of vehicles. A principal method to evaluate the total environmental effect of a vehicle is through the analysis of its life cycle. However, most of these analysis focused on the production and use phase, and little work has been performed to understand the material value of end-of-life vehicles (ELVs). Previous works have not comprehensively considered the benefits of the phase above that can provide a different perspective on the total vehicle life cycle. Our study clarifies how the materials obtained from scrapped vehicles are used, and we propose an analysis method to assess their benefits by defining the concepts of energy and CO2 reductions. The Japanese ELV market is presented as a case study, and the material flow is elaborated. The energy and CO2 reductions are calculated as 52.8 MJ and 2.80 kg CO2 per kilogram of vehicle, demonstrating the importance of the analyzed phase in the entire life cycle. Finally, possible changes in ELV recycling to improve their benefits are discussed.