Introduction

Consumerism lifestyle has pushed mass industrialisation and accumulated an incredible volume of resources. The depletion of resource is therefore in extremely urgent status to meet the increasing demand of consumption. According to (Global Footprint Network, 2016), today it takes the equivalent of 1.6 planets Earth to provide the resources we use and absorb our waste. United Nations (UN) also predict the need of two Earths by the 2030s if current population and consumption trends continue (Figure 1-1). This situation has also made the access to materials a critical issue of national security of many nations. The increasing amount of waste is also another consequence of this phenomenon. Most of wastes generally have to go into landfill or incineration for disposal because of economic reasons. These solutions however have negative impacts on environment.

Consumption can be defined traditionally at the end of economic activities from extraction of resources to production of goods/services and their distribution among people and groups; and the goods and services themselves come to be used goods (Goodwin et al., 2013). However, in the new concept, consumption can create the resource base for the next round of economy activity and go to the circular economy framework on using recycling activities. Recycling now plays an important role in waste management on reducing waste disposal and improving the resource efficiency. In economic view, this alternative depends largely on the cost of conventional production from primary resources and the waste disposal fees. Since the industrial revolution, the low-cost mass production techniques reduced the costs of materials and products; it also reduced the interest on recycling. For high technology recycling, it is hard to be chosen as solution among cheaper disposal options without legislation barrier.

Since its invention by Edison over 100 years ago (Edison, 1880), carbon fibre (CF) has been used in numerous applications (Figure 1-2), such as aerospace, automotive, sports... Due to its lightness, and good mechanical properties, CF is excellent reinforcement fibre in composite. Moreover, with the good corrosion resistance, carbon fibre composites (CFC) have substituted increasingly conventional materials (e.g. steel, aluminium alloys). In transport applications, the use of CFC has double effects: weight reduction of vehicles (e.g. aircraft, car) and reduction of fuel consumption as consequence. The recent aircraft models of Boeing (B787) and Airbus (A350) have high content of CFC with more than 50 % in this material. The market of Carbon Fibre Reinforced Polymers (CFRP), the main CFC, will need 175 000 tonnes/year with the annual growth rate of 11 % in 2021 (Witten et al., 2015).

Figure 1-2: Carbon fibre uses history (www.utsi.edu)

While the use of CFRP provides many advantages, these materials also present some challenges for environment. The growing volume of CFRP in applications today will lead to larger quantity of CFRP waste generated tomorrow. The production of CF consumes high energy and releases hazardous gas (Suzuki and Takahashi, 2005; Grzanka, 2014). Otherwise, the global demand of carbon fibre is expected to exceed production capacity in 2015 if growth remains at this rate. In that context, the interest of recycling is threefold: first, it is necessary to limit the accumulation of waste that is likely to be generated; second, recycling could be a fibre supply solution in order to meet future demand (Black, 2012) and third, recycling could be expected as a less-energy-intensive operation with lower environmental impact than the traditional way to produce CFRP, bypassing some operation steps.

wastes are currently landfilled or incinerated (Yang et al., 2012). At present, there are no legislations which are specific for composite wastes in general. However, they can be concerned by the regulations applied on the components in composite (e.g. organic substances, hazardous additives) like the European Directive on Landfill of Waste (Directive 1999/31/EC, 1999) or the applications generating waste streams like the End-of-life Vehicle Directive (Directive 2000/53/EC, 2000).

Facing with the increasing volume of CFRP waste, the waste management of these materials is poorly prepared on both techniques and legislations. The current solutions with landfill and incineration will be no longer the best choices in future regarding the ban of landfill and the restriction of waste incineration in several countries. Otherwise, these techniques lead to the loss of recoverable products in CFRP wastes such as recycled carbon fibre which can be reinserted to highly-demanded CF markets. CFRP recycling techniques have had important progressions on operation process and quality of recycled products. For Fibre Reinforced Polymer Composites in general, although only grinding and pyrolysis are industrialised, a wide range of recycling techniques are on development (Oliveux et al., 2015a) with different conditions and multiple products. The advancement of recycling techniques helps widening the portfolio of options for CFRP waste treatment.

In this context, the objective of this research project is to study the CFRP waste management with a set of treatment options. The economic and environmental assessments tools are used to design the relevant networks in order to take into account both economic and environmental advantages and drawbacks between waste treatment options. With these criteria, the optimisation process will be carried out in waste management model. Besides, the markets or recovered products will be integrated in waste management. In this introduction chapter, the next section is dedicated to the general presentation of composites materials including the main types, their concepts and the principal components, especially Carbon Fibre reinforced Polymer type. Its components and fabrication process will be briefly presented in order to identify the waste types that will be tackled in the studied system and the potential benefit of recycling over conventional production. The state of the art of CFRP recycling techniques is the core of the section 1.3. Section 1.4 will present a review on the models and the methods for modelling waste management. These concepts will be applied for modelling the system of CFRP waste management and its optimisation. The scientific objective and motivation of the study in section 1.5 will conclude this chapter.