Environmental aspects of use of recycled carbon fibre composites in automotive applications

The high cost and energy intensity of virgin carbon fibre manufacture provides an opportunity to recover substantial value from carbon fibre reinforced plastic wastes. In this study, we assess the life cycle environmental implications of recovering carbon fibre and producing composite materials as substitutes for conventional and proposed lightweight materials in automotive applications (e.g., steel, aluminium, virgin carbon fibre). Key parameters for the recycled carbon fibre materials, including fibre volume fraction and fibre alignment, are investigated to identify beneficial uses of recycled carbon fibre in the automotive sector. Recycled carbon fibre components can achieve the lowest life cycle environmental impacts of all materials considered, although the actual impact is highly dependent on the design criteria (λ value) of the specific component. Low production impacts associated with recycled carbon fibre components are observed relative to lightweight competitor materials (e.g., aluminium, virgin carbon fibre reinforced plastic). In addition, recycled carbon fibre components have low in-use energy use due to mass reductions and associated reduction in mass-induced fuel consumption. The results demonstrate environmental feasibility of the CFRP recycling materials, supporting the emerging commercialisation of CF recycling technologies and identifying significant potential market opportunities in the automotive sector.


INTRODUCTION
As carbon fibre reinforced plastic (CFRP) is increasingly used in aerospace and finding emerging applications in the automotive sector, 1 systems need to be developed to deal with waste arising from associated manufacturing processes and end-of-life products. In 2015, carbon fibre (CF) demand was estimated at about 68,000 tonnes, of which 18,000 tonnes became manufacturing waste; the remaining 50,000 tonnes of CFs will end up as end-of-life products after expected lifetimes ranging from 2-40 years, depending on their application. 2 In the USA and Europe, 6,000-8,000 commercial aircraft are expected to come to their end-oflife by 2030, generating an estimated 3,000 tonnes of CFRP scrap per annum. 3,4 More recent wide-body planes, Airbus A350 and Boeing 787 Dreamliner, have seen the expanded use of CFRP materials, more than 50% weight. The amount of CFRP to be recycled in the future will grow significantly when recent aircrafts will be taken out of service. Current waste policies are supportive of recycling initiatives, including general policies (e.g., the EU Directive on Landfill of Waste 5 ) and application-specific legislation (e.g., the End-of-life Vehicle Directive 6 ). They also align with aerospace industry targets to increase recovery rates for manufacturing and endof-life wastes: Airbus targets for 95% of CFRP manufacturing process wastes to go through a recycling channel, with 5% of the waste products to be recycled back into the aerospace sector. 7 The high cost and energy intensity of virgin carbon fibre (vCF) manufacture also provide an opportunity to recover substantial value from CFRP wastes: recovered carbon fibre (rCF) could reduce environmental impacts relative to vCF production, while the potentially lower cost of rCF could enable new markets for lightweight materials. To support the development of rCF markets, technology demonstrators (e.g., rCF seatback demonstrators-aircraft seatback (36% aligned rCF volume fraction with PPS matrix) and automobile seat base (42% aligned rCF volume fraction with PP resin)) have established the viability of CFRP recycling processes and composite manufacturing from rCF for aerospace and automotive applications. 8,9 However, there is still limited understanding as to the life cycle environmental impacts associated with CFRP recycling, reuse of rCF in composite manufacture, and potential uses of the resulting materials.
The current processes for the recovery of CF from end-of-life components and manufacturing scrap can be categorised into mechanical recycling, thermal recycling and chemical recycling processes. 10 Maintaining the mechanical properties of CF through the recycling processes is a key challenge to overcome in developing a commercial recovery process and trade-offs clearly exist between the competing recycling technologies: the fluidised bed process, wherein the polymer matrix is oxidised to enable fibre recovery, 10 can accommodate contamination in endof-life CFRP waste and shows almost no reduction in modulus and 18%-50% reduction intensile strength relative to vCF , 10,11 this process has been developed to large lab scale.
Several processes are now transitioning from lab scale to commercial facilities, e.g. Carbon Conversions in the USA with an annual capacity of 2,000 t/yr 12 and ELG Carbon Fibre Ltd. in UK using a pyrolysis recycling process with an annual capacity of 2,000 t/yr. 2 However, there is very little publicly available information regarding the performance of commercial scale facilities (e.g. energy efficiency or fibre recovery rate).
The handling of rCF and its processing to CFRP are difficult due to its discontinuous, 3D random filamentised form and low bulk density; these challenges risk limiting the penetration of rCF into vCF markets. A range of techniques have been explored for preparing composite materials from rCF, involving rCF-specific conversion processes (wet papermaking process 13,14 and fibre alignment [14][15][16], and adaptations of composite manufacture techniques (sheet moulding compound, 17 compression moulding of non-woven mats and aligned mats, 13,18 injection moulding 19 ). The wet papermaking process has been successfully demonstrated as an efficient way to produce planar non-woven random mats from rCF manufactured into CFRP with fibre volume fraction (vf) of 20%-40%. 13,14 The fibre alignment process is under investigation to achieve higher fibre volume fractions and allow greater control of fibre orientation and resulting CFRP properties. 16,20 Impregnation of non-woven rCF mats with polymer has been successfully employed in developing composite materials via compression moulding and injection moulding techniques. 13,19 Tensile properties (i.e., tensile modulus, strength and impact strength) of composites reinforced with the rCF are comparable to similar materials produced with vCF and other general engineering materials like glass fibre reinforced polymer. 14,19 As the processes of CFRP recycling, rCF processing, and CFRP manufacture are energy intensive, there is a need to assess the environmental impacts of the production routes.
Life cycle assessment (LCA) is a standardised method that can be used to quantify the environmental impacts of a product over its complete life cycle, including raw material production, product manufacture, use and end-of-life waste management. 21,22 Previous studies have applied LCA methods to investigate vCF for lightweight vehicle applications but insights of these studies are not consistent. While some have found lightweight CFRP components to reduce life cycle energy use and greenhouse gas (GHG) emissions, [23][24][25] contradicting studies have found that weight savings and associated improved fuel economy during the vehicle life are compromised by the energy intensity of vCF production, resulting in minimal net benefit 24 or even an increase in GHG emissions over the full life cycle. 26 This inconsistency arises primarily from data limitations for vCF production (as we have noted previously 27 ), assumptions regarding vCF production process energy sources and the ratio of vCF part mass to original part mass. All studies, however, clearly indicate that CF production is energy intensive and associated with significant GHG emissions relative to conventional materials.
Using rCF in place of vCF can potentially reduce the environmental impacts of material production; however, maintaining similar material properties with vCF is crucial in order to realise benefits across the full life cycle (including production and use). The few studies that have assessed the cradle-to-gate environmental impacts of CFRP recycling have investigated different recycling technologies (fluidised bed, pyrolysis, mechanical recycling), generally concluding that CF recycling is far less impacting than vCF manufacture; however, these studies have not considered the use phase of rCF materials. 24,[27][28][29] Overall, prior life cycle studies of CF recycling are limited by the availability of relevant data for recycling and rCFRP manufacturing processes and, to date, none has considered the use of rCFRP as lightweight materials in automotive applications.
Recycled CF has significant potential as a low cost and low environmental impact material for transportation applications. However, there is limited understanding as to the overall environmental impacts of the CFRP recycling, composite manufacture with rCF, and subsequent use of these materials. In this paper, life cycle models are developed to assess the performance of CF recycling, via fluidised bed process, and reuse in automotive applications.
A set of rCFRP manufacturing approaches (compression moulding; injection moulding) are considered and material production and its use are evaluated in a vehicle over its full lifetime.
Case study automotive components are considered under different design constraints. The results are then compared with conventional automotive materials (steel) and competitor lightweight materials (aluminium, vCFRP) to identify opportunities where rCF can achieve a net environmental benefit.

METHOD
The goal of this study is to assess the life cycle environmental impacts of CFRP recycling and use of rCF for composite manufacture for automotive applications. Activities included within the life cycle model are shown in Figure S1, beginning with collected CFRP waste and including all subsequent activities related to CFRP recycling, rCF processing, rCFRP manufacture, and use phase. Recycled CF is assumed to be recovered from a fluidised bed recycling process, as analysed previously. 27 Three rCFRP production pathways are considered: 1) Random structure -Compression Moulding: rCF is processed by a wet papermaking process prior to impregnation with epoxy resin and compression moulding. 20%vf, 30%vf, and 40%vf are considered under moulding pressure of 2 to 14 MPa.
2) Aligned -Compression Moulding: rCF is processed by a fibre alignment process prior to compression moulded with epoxy resin. 50%vf and 60%vf are considered under moulding pressure of 8 MPa.
3) Random structure -Injection Moulding: rCF is processed by wet papermaking and subsequently chopped prior to compounded with polypropylene (PP); rCF-PP pellets are subsequently injection moulded. Fibre volume fraction is 18%vf.
CF-based materials are also compared with mild steel, as a conventional automotive material, and aluminium, a potential lightweight metal.
For recycling, a 'cradle to gate' approach is taken which includes 'initial resource extraction' (i.e., recovery of rCF for rCFRP products) and the manufacture of composite materials from rCF and the use. Upstream activities preceding the CFRP becoming a waste material are thus excluded from this analysis. For the vCF-based materials and metals (steel, aluminium), life cycle models include 'cradle to gate' activities from initial resource extraction (e.g. CF feedstock production; ore mining), material production, component manufacture, and the use.
We assume primary aluminium (no recycled content) is used in component manufacture to meet strict alloy composition limits.
Process models of the fluidised bed recycling, rCF conversion to an intermediate material (i.e., wet-papermaking/ fibre alignment) and the subsequent CFRP manufacture (i.e., compression moulding/ injection moulding) are developed to estimate the energy and material requirements of commercially operating facilities. This data is supplemented with databases to estimate impacts of producing and using material and energy inputs (e.g., Gabi 31 Ecoinvent 32 ) assuming all activities to occur in the UK. Additional details related to waste CFRP recycling, rCF processing, and CFRP manufacture are included in the subsequent subsections.
Life cycle models are developed to assess the environmental implications of substituting steel with rCF materials and competing lightweight materials. Two environmental metrics are considered: primary energy demand (PED); and global warming potential (GWP), based on the most recent IPCC 100-year global warming potential factors to quantify GWP in terms of CO2 equivalents (CO2eq.). 33 A general approach is taken to ensure functional equivalence of producing automotive components from the set of materials based on the design material index (λ), a variable which is specific to the design criteria for any specific component. For further details see the references by Patton et al and Ashby. 34,35 The component thickness is treated as a variable that is adjusted based on each material's properties and the specific applications design material index (see Section 2.5 for further details). Analysis results are presented on a normalised basis (relative to the mild steel reference material), and can thereby be easily applied to subsequent analyses that are undertaken for specific components where the material design index is known.

Carbon fibre recycling
A fluidised bed process is considered for the recycling of CFRP waste in this study. In the fluidised bed reactor, the epoxy resin is oxidised at a temperature in excess of 500 C. The gas stream is able to elutriate the released fibres and transport out of the fluidised sand bed for subsequent separation by cyclone. After fibre separation, the gas stream is directed to a hightemperature combustion chamber to fully oxidise the polymer decomposition products. Energy is recovered to preheat inlet air to the bed. Mass and energy models of the fluidised bed process under varying conditions (e.g., annual throughput, CFRP feed rate) and insights regarding process energy efficiency and "gate-to-gate" environmental impacts have been presented previously. 27 For the current study, a plant capacity of 500 t rCF/yr and feed rate of 9 kg rCF/hrm 2 are considered corresponding to energy requirements of 1.9 MJ natural gas/kg rCF and 1.6 kWh electricity/kg rCF.

Virgin carbon fibre manufacture
The manufacture of vCF is modelled based on existing literature data. The life cycle inventory data input to our LCA models information is described previously 27 and comprises data from literature and life cycle databases, with parameters selected based on literature consensus, expert opinion and results from a confidential industrial dataset. Publicly available data on vCF manufacture is limited and, in many cases, is lacking in key details that should be incorporated into LCA studies, in particular variations in CF mechanical properties (high strength vs intermediate modulus) and corresponding energy requirements/ environmental impacts. In this study, high strength vCF is assumed to be manufactured from a polyacrylonitrile (PAN) precursor followed by subsequent stabilization, carbonization, surface treatment and sizing processes. Based on a literature value for mass efficiency of 55%-62%, 36, 37 a representative mass yield is assumed to be 58%. All inventory data have been recalculated relative to 1 kg CF and the total actual energy consumption is estimated to 149.4 MJ electricity, 177.8 MJ natural gas and 31.4 kg steam. Direct process emissions are estimated based on available data 36 and adjusted to reflect the mass efficiency assumed in the current assessment.

Carbon fibre conversion process
Two processes are considered to convert rCF to a form suitable for composite manufacture: wet papermaking to produce a random oriented mat, 13 and fibre alignment to produce a unidirectional fibre mat. 38 Mass and energy balances of these two rCF processing methods are established based on key processing parameters as described below.
To form a random mat via the wet-papermaking process, CF is first dispersed in a viscous aqueous solution to form a fibre suspension (assumed here to be a 0.1%vf to avoid agglomeration of fibres 39 ) by stirring for 24 hours at a certain rotational speed. The fibres are then deposited on a conveyor and washed, dewatered and dried to produce a random mat.
Energy requirements of each associated activity are estimated based on experimental data, parameter optimisation to minimise energy consumption and, where available, energy efficiency data of standard equipment. 40,41 Further details of the papermaking process model development were reported previously. 27 A fibre alignment process is also considered wherein the fibre suspension is injected onto a mesh screen inside a rotating drum and the nozzle filters and aligns the fibres prior to dewatering/drying. This fibre alignment process is still under development, and so energy consumption is estimated based on a target for technology development (22 MJ/kg rCF mat) and summarized in the Supporting Information (Section S1.1). Due to confidentiality of the process in the development, limited details of the fibre alignment process can be given. The implications of this assumption on results are discussed in Section 3.4.

Compression moulding
Compression moulding production of CFRP requires CF mats (random and aligned mats from rCF; prepreg from vCF) and epoxy resin film to be cut to size required to fit into the mould with cutting energy use of 0.37 MJ/kg. 42 Before applying compression pressure, a standard vacuum bagging procedure is implemented to reduce air entrapment during ply collation and thus to reduce the void content inside the composite. For random rCFRP, the mould is subsequently compressed under pressure of 2 to 14 MPa depending on fibre volume fraction required, with higher fibre fraction components requiring higher pressures. 13 For aligned rCFRP, the compression pressure is lower (8 MPa). 16 During compression moulding, materials are heated to 120 °C for curing. A detailed description of our compression moulding energy use models presented in our earlier work 27 and is summarised in the Supporting Information (Section S1.2.1).

Injection moulding
Injection moulding has been successfully demonstrated to be an efficient way to process rCF into CFRP materials 19 and is capable of achieving similar mechanical properties to materials produced from injection moulded vCF. 43 First, the CF is compounded with a thermoplastic matrix (polypropylene) to produce composite pellets for input to the injection moulding. To produce rCF-PP pellets, randomly aligned rCF mat (100 g/m 2 ) is chopped to pellets 4 mm wide and 6 mm long in the current study. This may not be the efficient method to manufacture rCF-PP pellets but will be optimized where available in the future study. To ensure bonding between the rCF and PP matrix, PP is first compounded with a coupling agent (maleic anhydride grafted polypropylene coupling agent, 5% by weight) via a screw extrusion process at 210 °C with a screw rotational speed of 80 rpm and a residence time of 130 s. The rCF pellets are subsequently compounded with the PP pellet at 18%vf (30% weight fraction (wt)) by screw extrusion (210 °C, 50 rpm, and 150 s residence time). For vCF, a coupling agent is assumed to be not required and so vCF-PP pellets can be produced by a single compounding step with chopped vCF and PP granules (18%vf; 30%wt) is required and is operated under the same conditions as the rCF-PP compounding step described above.
For injection moulding of CF-PP pellets to form the automotive components, recommended parameters are presented in the SI. Although injection moulding is normally used to manufacture relatively small parts and might not be the most appropriate manufacturing technique for larger parts such as automotive closure panels, it is still a comparable alternative manufacturing route for rCF and worthwhile for its investigation of environmental feasibility.
Compounding energy consumption is calculated accounting for polymer melting, screw driving, and cooling and combined with output of the compounder obtained by the function of solid flow rate and simulation of factors in eq S3. Injection moulding energy requirements are calculated to account for specific component geometry (mould cavity volume, projected area).
Moulding machine parameters, specifically the clamping force, injection pressure/temperature, ejection temperature, and screw drive rotational speed, are used to determine power requirements and combined with cycle time to estimate total energy requirements, based on relationships developed in prior studies. 44,45 Further details on the injection moulding model development and parameters are given in Section S1.2.2 in supporting information.

Autoclave moulding
Autoclave moulding is commonly utilised by the aerospace industry where heat and pressure are applied to prepreg laminates in a pressure vessel. It enables the manufacture of CFRP components with high fibre volume fractions and low void content but requiring intensive energy and high costs of both initial acquisition and use. In general, CF is pre-impregnated with a thermoset resin before being put into a mould and curing under typical pressure of 0.6-

Functional unit
This study focuses on the development of flexible models capable of assessing a range of different automotive components, rather than focusing on a case study of a single component.  Table S1.

Use phase analysis
During the use phase, the automotive components will impact vehicle fuel consumption due to their weight and corresponding mass-induced fuel consumption without powertrain resizing.
In-use energy consumption is calculated with the Physical Emission Rate Estimator developed by the US Environmental Protection Agency 55 and the mathematical model 56 for mass induced fuel consumption. In brief, this method estimates vehicle power demand, which is impacted by total vehicle weight , and integrates over a standard driving cycle as below 56 Where Hf is lower heating value of gasoline (32.20MJ/l), 57 ƞt is transmission efficiency, ƞi is indicated (thermodynamic) engine efficiency, v is vehicle speed (m/s), m is vehicle mass (kg), a is vehicle acceleration (m/s 2 ), g is gravitational constant, grade is road grade (0 in the US EPA test), A is target rolling coefficient, B is target rotating coefficient, C is target aerodynamic coefficient. The US EPA combined fuel economy driving cycle is considered.
Model parameters for a set of production vehicles are available, 58 for this analysis a Ford Fusion is selected as a representative mid-size light duty vehicle, which has a mass-induced fuel consumption factor of 0.38 L/(100km·100kg). Mass induced fuel consumption is calculated based on the differences in vehicle mass from utilising lightweight materials assuming no effect of material substitution on the vehicle aerodynamics. As a base case, a typical vehicle life of 200,000 km. 24,59 The sensitivity of results to these key parameters are evaluated.
Achieving higher fibre fractions through alignment can deliver further PED reductions of up to 56% for the highest fibre content considered here (60%vf), demonstrating the potential advantages to be seen from developing alignment techniques. This finding, however, is dependent on alignment technologies meeting the development target energy consumption of 22 MJ/kg. As actual fibre alignment energy requirements may be more or less than this target, the break-even alignment energy consumption for aligned rCFRP materials are calculated to retain superior life cycle environmental performance over the best-case randomly-aligned rCFRP material. This breakeven point is found to be 95 MJ/kg and 110 MJ/kg to achieve similar life cycle PED and GWP impacts respectively. This result suggests that, should technology development objectives be achieved, then aligned rCFRP would be a promising low life cycle environmental impact material for automotive applications.
In contrast, the energy-and GHG-intensive manufacture of vCF precludes significant reductions in life cycle PED and GWP in all but the most promising substitution scenario (λ=3).
In agreement with previous analyses, 23,24 results indicate that although woven vCFRP components can achieve the lowest mass of all alternative materials considered in this study, in-use fuel savings can be counteracted by the impacts of vCF manufacture. In comparison, rCFRP components benefit from the low energy-intensity of rCF recovery (compared to vCF manufacture) and can thereby achieve significant reductions in life cycle energy use and GHG emissions. The lightweight aluminium components also present significant reductions in PED and GWP relative to steel mainly due to the moderate production impacts and large use phase fuel savings. They can achieve similar PED and GWP reductions with woven vCFRP components relative to steel, but still underperform the rCFRP components.
For λ=1, for columns and beams under tension loadings (e.g., a window frame), there is limited scope for lightweighting with any of the materials considered in the present study. Only aligned rCFRP with high fibre volume fractions (i.e., 50% vf and 60% vf) can reduce life cycle PED and GWP relative to steel.

Sensitivity analysis
The study results are sensitive to a number of key parameters, including material substitution assumptions, impacts of vCF manufacture, GHG-intensity of electricity inputs, impact of component weight on in-use energy consumption, and vehicle lifetime. Detailed sensitivity analysis results are presented in the Supporting Information (Section S2.2 and Figures S5-S7) and are summarised here.
Uncertainty associated with vCF production impacts arise from data quality issues as well as regional variability of electricity generation sources and associated impacts. The quality of life cycle inventory data for vCF manufacture is poor: publicly available data is limited; vCF production energy requirement and sources vary significantly (~200 to 600 MJ/kg from a mix of electricity, natural gas, and steam); 4, 23, 37, 61 and studies have not linked production data to CF properties despite different processing conditions required to achieve high modulus and high strength CF. If the lower end of production energy estimates can be achieved, the life cycle GHG emissions of vCF-based materials correspondingly decrease by 17% (Figure 3, for λ=2 and Supporting Information Figure S5), whereas the higher energy requirement estimate would increase emissions by 36%.
Life cycle GHG emissions are sensitive to the generation mix of input electricity; however, regardless of electricity source, components manufactured with rCF achieve the lowest emissions of all materials considered in this study ( Figure 3). By utilising hydroelectric power to produce the CF-based materials, life cycle GHG emissions can be reduced by 35% (woven vCF; aligned rCFRP) and 20% (random rCFRP) relative to the base case electricity source (UK grid mix). With increasing non-renewable content of electricity, the ability of alternative materials to reduce GHG emissions relative to steel declines. As such, on-going decarbonisation of the electricity sector seen recently in many countries will serve to improve the relative performance of lightweight materials relative to conventional steel materials. Uncertainty in vehicle life does not alter the finding that rCFRP components achieve the lowest life cycle PED and GWP impact (see Figure S5 in the SI  Figure S6). However, across the range of values considered in the study, rCFRP materials maintain the lowest life cycle environmental impact.

Discussion
Lightweight materials for automotive applications can reduce in-use environmental impacts and enable alternative transmissions (e.g., range extension for electric vehicles). However, weight saving is not always a reliable indicator of environmental performance as this single metric ignores the impacts associated with material production. Cost and embodied energy barriers associated with the production of lightweight metals and vCF materials can, in some cases, outweigh weight reduction and environmental benefits associated with reduced fuel use during the vehicle life. In the current study, the advantages of rCFRP materials for automotive applications are demonstrated and compared to competing lightweight materials (aluminium, vCF). Components produced from rCFRP can achieve similar or greater weight reductions to competing lightweight materials while substantially reducing the impacts of production due to the low energy intensity of recycling and rCF processing activities.
For many components; while exhibiting low embodied energy/GHG emissions, the use of rCFRP results in significant reduction in GWP and PED relative to conventional steel components primarily due to the low energy intensity of recycling and large use phase fuel savings. The overall finding supports the emerging commercialisation of CF recycling technologies and identifies significant potential market opportunities in the automotive sector.
It has the potential to inform industry and policy-makers regarding environmental impacts related to CFRP recycling technologies and the development of relevant policies to encourage suitable utilisation of rCF materials. By adjusting model values, the model can be used to evaluate environmental impacts of other jurisdictions, co-location scenarios, co-production scenarios; similarly, the model could be expanded to include additional environmental impact metrics, e.g.,those related to non-GHG air emissions from recycling, manufacturing, and use phases.
Recycled CF materials demonstrate significant environmental benefits for material selection processes and empower eco-friendly lightweighting strategies in the automotive sector.
Identifying specific components where rCFRP materials can achieve substantial weight reductions is thus critical to maximising their potential environmental benefits. In the current study, a range of design material constraints are considered. Further investigations must extend these methods that efficiently link component design criteria to life cycle environmental impact to integrate this approach with finite element analysis and whole-vehicle design considerations in order to identify the most promising applications.
While the environmental performance of rCFRP materials is presently demonstrated, there is still less certainty as to the financial viability of their production and application in the automotive sector. Future work will be focused on the financial analysis of the recycling process and the subsequent manufacture of rCFRP and combined with LCA method to support material design and investigate applications of rCFRP for best trade-offs between environment impacts and costs. Also of concern is the mismatch between rCF availability (estimated at about 50,000 t/yr in 2017 61 ) and potential demands in the automotive sector, which produced in excess of 95 million vehicles globally in 2015, 62 and other potential applications of rCF materials. It will therefore be essential to identify optimal rCF utilisation opportunities that maximise net environmental and financial benefits. Environmental assessment and further life cycle cost analysis will thus play a crucial role in identifying suitable waste management strategies to address the emerging waste burden of end-of-life and manufacturing scrap CFRP materials and to determine beneficial uses of rCF in automotive sector or in other applications.

Supporting Information
Additional details on the overall method, description of process modelling of fibre alignment process, CFRP manufacture and environmental impact and sensitivity analysis results.
Equations S1-S9 explain how the energy requirements of recycling and remanufacturing process are related to the processing parameters. Validations of process modelling are given.
Figures S1-S6 show overview of recycling pathways, production PED of components, sensitivity of GHG emission to manufacture vCF, sensitivity of PED and GWP to travelling distance and mass induced fuel consumption. Table S1 shows mechanical properties used in the paper.

AUTHOR INFORMATION
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