The development of products with improved environmental performance is regarded as a crucial component of companies’ commitment towards sustainable development (Rodrigues, Pigosso and McAloone [110]). This is why in recent decades the sustainability concept has acquired growing importance and a large number of methodologies, tools, standards and regulations have been developed to promote the implementation of its principles inside industrial companies (Plouffe et al. [111] ).
In this respect and as demonstrated by Luttropp and Lagerstedt [112] acting in the design phase is the most important moment inside a product lifetime. As van Schaik and Reuter [96] state, during this phase not only the specifications are set, but also the quality of recycling, which is conditioned by the liberation of materials during shredding which in turn strongly depends on the design. In the industrial field, eco-design can be defined as an approach to consider and integrate environmental aspects in the product development process through the application of strategies aimed at reducing the negative environmental impact along the product lifetime (Rossi, Germani and Zamagni [113]). According to Hollander, Bakker and Hultink [114] and Luttropp and Lagerstedt [112] eco-design provides product designers with a range of guiding principles, strategies and methods and encourages better environmental product performance by means of:
closing resource loops, minimizing resource consumption, promoting repair and upgrading, product long life and recycling.
In Europe, eco-design requirements are defined by the European Directive 2009/125/EC, but this legislation applies to all products related to energy with the exception of vehicles [115]. For the latter, eco-design approaches are focused on ensuring that the requirements established by the ELV EU Directive [116] and polluted emissions EU regulations [117] are met. In addition to complying with these requirements, vehicle manufacturers can also implement in their products eco-design approaches according to ISO 14006, as has been the case of some vehicle companies like SEAT S.A [118]. According to Aran-Landin and Heras-Saizarbitoria [119], ISO 14006 has as main aim to reduce the environmental impact of companies along the following phases: product design, manufacturing, transport, operation, maintenance and EoL.
In the light of the increasing environmental impacts and raw material pressure of the vehicle sector, it becomes crucial to apply eco-design approaches and so increase the resource efficiency throughout a car’s life cycle. Common methods used by different authors such as Hernandez et al. [84], Lee et al. [124], Mayyas, Mayyas and Omar [125], Delegu et al. [126], Ozbilen, Dincer, and Hosseini [127] and Viñoles-Cebolla, Bastante-Ceca and Capuz-Rizo [128] for the eco-design of vehicle components is through Life Cycle Assessment (LCA). They are aimed at assessing products impacts from a cradle to grave perspective, considering material production, product
production, product use and product End of Life (EoL). LCA also serve to assess the environmental performance of products. This way, for instance, Tagliaferri et al. [125] undertook a Life Cycle Assessment (LCA) with Ecoinvent [126] data and compared an ICEV and a BEV.
Meanwhile, Domingues et al. [127] applied a multi-criteria decision and a LCA methodology to classify different LDV (ICEV, PHEV, BEV) according to their environmental impacts. Similarly, Bauer et al. [128] made an evaluation of the environmental performance of current and future LDV, assessing four types of vehicles: ICEV, PHEV, BEV and fuel cell vehicles (FCV).
In the case of the material production phase, Song and Lee [129] state that common methods are based on assessing the impacts related to the acquisition of natural resources and their later processing by means of using specific LCA tools such as GaBi or SimaPro [130]. Yet according to Amini et al. [89] there is an open debate whether these methods reflect well the depletion of natural resources. In this respect, this thesis proposes an alternative method based on the second law of thermodynamics through rarity indicator to identify critical components and so advise for eco-design approaches.
2.6. Conclusions
After an analysis of the state of the art of resource efficiency in the automobile sector the following conclusions serve as arguments to develop this Thesis:
In the literature, there are already assessments of raw material use in vehicles. Yet these are still very coarse and in any case they do not provide information regarding where these materials are found in the car. This is why, to the author’s knowledge, this Thesis provides the most detailed analysis of metals and components used in vehicles (Chapter 4).
There is a concern about the availability of raw materials for the next decades and some studies have addressed the issue of possible supply shortages for certain technologies.
That said, an in-depth assessment about how will be the vehicle sector affected by metal shortages is missing. This Thesis addresses this gap, Chapter 5 and Chapter 7 possible bottlenecks and the most strategic metals for the automobile sector until 2050 are presented.
The common approach for measuring resource efficiency in the literature is through weight, thereby ignoring the quality of raw materials. For this reason, in this Thesis (Chapter 6) an alternative unit of measure called thermodynamic rarity (explained in Chapter 3) is used to assess the resource efficiency of vehicles. This method takes into account not only the quantity but also the quality of any material and it allows to measure the resource efficiency of vehicle components or vehicles as a whole.
From the literature review it has become evident that current recycling processes do not incentivize the recycling of scarce metals. Yet an assessment of what is the loss of the mineral capital due to the downcycling of these metals is missing. This is why in this Thesis (Chapter 8) an analysis of the most downcycled metals and components in a car is done, giving a global vision about the huge amount of valuable raw materials that become lost. Some recommendations to reduce such losses are also provided.
Eco-design of vehicles is key to improve their sustainability. That said, if resource efficiency does not consider the quality of all raw materials used, eco-design cannot be properly done. So in this Thesis (Chapter 9) eco-design recommendations are proposed for the most critical components identified in the vehicle using a thermodynamic approach.
Chapter 3. Fundamentals.
3.1. Introduction to the chapter
Chapter Fundamentals presents some basic principles required to obtain a global vision about the methods applied in each Paper. For this endeavor, this Chapter is divided into the followings two main sections:
Bottlenecks identification: This section will be useful to understand the method to assess the possible raw material bottlenecks in the vehicle manufacturing sector until 2050.
Exergy approach and reference state to quantify the physical value of metals: This section will explain how resource efficiency can be assessed from a physical and universal point of view by means of thermodynamics.