MaTrace: Tracing the Fate of Materials over Time and Across Products in Open-Loop Recycling

Abstract

Even for metals, open-loop recycling is more common than closed-loop recycling due, among other factors, to the degradation of quality in the end-of-life (EoL) phase. Open-loop recycling is subject to loss of functionality of original materials, dissipation in forms that are difficult to recover, and recovered metals might need dilution with primary metals to meet quality requirements. Sustainable management of metal resources calls for the minimization of these losses. Imperative to this is quantitative tracking of the fate of materials across different stages, products, and losses. A new input-output analysis (IO) based model of dynamic material flow analysis (MFA) is presented that can trace the fate of materials over time and across products in open-loop recycling taking explicit consideration of losses and the quality of scrap into account. Application to car steel recovered from EoL vehicles (ELV) showed that after 50 years around 80% of the steel is used in products, mostly buildings and civil engineering (infrastructure), with the rest mostly resided in unrecovered obsolete infrastructure and refinery losses. Sensitivity analysis was conducted to evaluate the effects of changes in product lifespan, and the quality of scrap.

Dynamic material flow analysis of nickel and chromium associated with steel materials by using matrace

“…In this study, cars, buildings, civil engineering, machines, containers, and others were considered as final products of significant importance for ferrous materials (for details please see Ref. [13]). The use of alloy elements in products includes both domestic and export uses.…”

“…The use of alloy elements in products includes both domestic and export uses. The initial values for parameters used in the analysis were taken from the previous study [13]. To determine the material flows of Ni and Cr, the yields of Ni and Cr during refining processes were taken from the literature [5,17].…”

“…Recently, dynamic material flow analysis has been gaining attention [7]. For sustainable management of metal resources, quantification of the dynamic flow of materials is needed, that is, quantitative tracing of the fate of materials over time across products and different types of losses [13]. Dynamic MFA has been successfully applied to reproduce historical flows and stocks of various metal resources and to project their possible future developments accommodating the end of life (EoL) phase and subsequent recycling [7,13].…”

“…For sustainable management of metal resources, quantification of the dynamic flow of materials is needed, that is, quantitative tracing of the fate of materials over time across products and different types of losses [13]. Dynamic MFA has been successfully applied to reproduce historical flows and stocks of various metal resources and to project their possible future developments accommodating the end of life (EoL) phase and subsequent recycling [7,13]. As in previous studies making use of dynamic MFAs regarding steel and its accompaniment, those studies examined the Japanese domestic material flow of steel [13] the average number of times of use and the average residence time of iron element in Japanese society [14].…”

“…Dynamic MFA has been successfully applied to reproduce historical flows and stocks of various metal resources and to project their possible future developments accommodating the end of life (EoL) phase and subsequent recycling [7,13]. As in previous studies making use of dynamic MFAs regarding steel and its accompaniment, those studies examined the Japanese domestic material flow of steel [13] the average number of times of use and the average residence time of iron element in Japanese society [14]. However, there are few studies using dynamic MFA to investigate alloy elements associated with steel materials.…”