System model for sustainable end-of-life vehicle treatment in the Australian context

A typical end-of-life (ELV) passenger vehicle contains around 30% non-metallic materials including such substances as plastics, textiles, and rubbers. It is mandatory in Europe, Japan, South Korea, China and Taiwan to reclaim non-metallic materials of ELVs – whereas in Australia, after shredding at metal shredding plants, non-metallic materials of ELVs are sent to landfill as Automobile Shredder Residue (ASR).<br><br>This research was twofold, aiming firstly to identify the most sustainable treatment practice for the reclamation of non-metallic materials of ELVs in the Australian context, and secondly to determine the most sustainable business model for the implementation of the selected ELV reclamation option for Australia. Based on definitions available in the literature, a sustainable ELV reclamation option was regarded as an environmentally effective, economically affordable, and socially acceptable ELV reclamation option. The literature also indicated that a sustainable business model for any ELV reclamation option was one which contributed to sustainable development of the company, and also society, through the creation of value (materials or energy) from non-metallic materials of ELVs.<br><br>The research assessed the applications of seven international best practice ELV reclamation options for the Australian context. Prior to sustainability assessments of the ELV reclamation options, the technical viability of the best practice ELV reclamation options were assessed through the multi-criteria assessment (MCA) method. The assessment utilised a set of relevant technical indicators available in the literature. Three of the seven ELV reclamation options were identified as being the most technically viable ELV reclamation options in the Australian context. These options were: (i) thermo-chemical treatment of ASR (pyrolysis/gasification), (ii) mechanical-physical separation of ASR, and (iii) injection of ELV plastics into blast furnaces.<br><br>The research then applied two different sustainability assessment models in order to assess the sustainability performance of the technically viable ELV reclamation options. These models were: (i) a model based on the ‘triple bottom line’ accounting approach and (ii) an emerging model referred to in the research as the ‘multi-dimensionality’ model. The ELV reclamation options were assessed against nine identified Australian-based sustainability indicators utilising the MCA method. With the application of said methodology thermo-chemical treatment of ASR was determined to be the most sustainable ELV reclamation option for Australia.<br><br>Following this determination the research identified three international business models for thermo-chemical treatment of ASR. These identified business models were then compared against a set of relevant assessment criteria available in the literature by the utilisation of the MCA method. The business model in which the proposed Australian ASR thermo-chemical plants would be established and operated by metal shredding companies performed the best in the MCA assessment.<br><br>The sustainability performance of the selected business model was assessed through two different sustainability assessment methods, namely the conceptual modelling method and the system dynamics method. The conceptual modelling method assessed the sustainability performance of the business model through analysis of the model’s ‘causal loop diagram (CLD)’. The analysis concluded that the selected business model was a sustainable business model as the reinforcing feedback loop of the CLD continually created value (energy) from non-metallic materials of ELVs, despite the presence of four balancing feedback loops in the CLD which tended to offset the value created by the business model. <br><br>The system dynamics method assessed the sustainability performance of the business model. It completed this exercise through analysing the behaviour-over-time (BOT) of the business model which had been created in the research through computer simulation of the model’s ‘stocks and flows diagram’. The potential annual electricity production of the business model was considered as the behaviour of the business model and so was plotted against the model’s lifespan of 25 years. The system dynamics analysis concluded that the selected business model was sustainable as its BOT followed the desirable BOT pattern mode of ‘Exponential Growth’ which has, at its basis, the business model continually, and increasingly, creating value (electricity) from non-metallic components of ELVs.<br><br>The BOT of the business model was verified and validated through recommended tests from the literature – including structure confirmation, sensitivity, and behaviour pattern tests. Such methodology provided sufficient confidence to consider the investigated business model as the most sustainable business model for ELV reclamation for Australia.