TA11B Modeling of Recycling and Waste Management
C123
8:00 AM - 12:00 PM, Tuesday
() Integrating LCA with dynamic MFA and pinch technology for assessing open loop recycling of materials.
Matsuno, Yasunari1, Fujimaki, Daisuke1, Daigo, Ichiro1, Adachi, Yoshihiro1, 1 Department of Materials Engineering, University of Tokyo, Tokyo, Japan
ABSTRACT- It has been recognized that LCA has a limitation in assessing the reduction potential of environmental impacts by open loop recycling of materials due to inevitable subjective judgments in setting system boundary. Whether recycling of post-consumer materials (scraps) could really substitute the production of primary materials is the key question in assessing open loop recycling, because there is usually degradation of post-consumer materials compared with primary materials. The authors have developed a model to assess the reduction potential of environmental impacts by recycling of materials, in which LCA is integrated with population balance model (PBM) and material pinch technology. This model can deal with dynamic aspects of the total material flow of scraps in a society and estimate the amount of the maximum recyclable scraps and primary material production, based on the quantitative and qualitative balance between supply and demand of scrap. Substitution rate of primary material by recycling of scraps (even for open loop recycling) can be obtained by this model, which will be dependent on the quality of the scrap. Case studies have been conducted for steel. In recycling of steel scraps from post-consumer products, there is usually contamination of undesirable tramp elements, e.g. Cu and Sn in steel scraps. So, the quality of steel scarps can be represented by the concentration of tramp elements in the scraps. The amount of steel scraps generated in Japan during 1990-2030 and their concentration of contaminated Cu were estimated. The maximum recyclable ratio of steel scraps in each year was investigated. The total CO2 emissions caused by crude steel production in Japan during 1990-2030 were estimated. Then, the substitution ratio of primary steel and the reduction potential of CO2 emissions by recycling of steel scraps were evaluated.
Key words: material pinch technology, open loop recycling, population balance model, steel