Can carbon fiber composites have a lower environmental impact than fiberglass?

Abstract

Carbon fiber composites are increasingly used to decrease fuel consumption in the use phase of vehicles. However, due to the energy intensive production, the reduced fuel consumption may not lead to life cycle environmental savings as much as for other lightweighting materials, for example fiberglass. This study uses life cycle assessment methodology to assess how different future development routes including using bio-based raw materials, microwave technology, and recycling of composites with the recovery of fibers influence the environmental impact of both carbon fiber composites and fiberglass in vehicles. Results show that combining different development routes could lead to carbon fiber composites with a lower environmental impact than fiberglass composites in the future and that recycling of composites with recovery of fibers is the route that alone shows the greatest potential.

Full text

Resources, Conservation & Recycling 181 (2022) 106234
Available online 23 February 2022
0921-3449/© 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Can carbon ber composites have a lower environmental impact
than berglass?
Frida Hermansson
a
,
*
, Sara Heimersson
a
, Matty Janssen
a
, Magdalena Svanstr¨
om
a
a
Division of Environmental Systems Analysis, Department of Technology Management and Economics, Chalmers University of Technology, Gothenburg, SE-412 96
Sweden
ARTICLE INFO
Keywords:
Carbon ber composites
Glass ber composites
Bio-based
Microwave technology
Recycling
Life cycle assessment
ABSTRACT
Carbon ber composites are increasingly used to decrease fuel consumption in the use phase of vehicles.
However, due to the energy intensive production, the reduced fuel consumption may not lead to life cycle
environmental savings as much as for other lightweighting materials, for example berglass. This study uses life
cycle assessment methodology to assess how different future development routes including using bio-based raw
materials, microwave technology, and recycling of composites with the recovery of bers inuence the envi-
ronmental impact of both carbon ber composites and berglass in vehicles. Results show that combining
different development routes could lead to carbon ber composites with a lower environmental impact than
berglass composites in the future and that recycling of composites with recovery of bers is the route that alone
shows the greatest potential.
1. Introduction
Lightweighting of vehicles is an effective way to reduce fuel con-
sumption during use. This can be done by substituting conventional
materials, such as metals, with composites (see e.g. Overly et al. (2002)
and Witik et al. (2011)). Two types of composites used in vehicles for the
purpose of lightweighting are glass ber reinforced polymers, GFRPs
(also known as berglass), and carbon ber reinforced polymers, CFRPs
(also known as carbon ber composites). Despite the fact that CFRPs are
both lighter and stiffer than GFRPs (Witik et al. (2011) and Elan-
chezhian et al. (2014)), which leads to a higher fuel saving capacity, the
use of CFRP instead of GFRP does not automatically lead to a lower
environmental impact throughout the vehicle’s life cycle. In fact, Her-
mansson et al. (2019) showed that the shift from GFRP to CFRP could
increase the climate impact and energy use, primarily as a result of the
energy intensive carbon ber production process. Previous studies have
suggested that the environmental impacts of CFRPs could be decreased
by transitioning to a bio-based raw material in carbon ber production
(see e.g. Das (2011)) and by recycling the composites and recovering the
bers (see e.g. Meng et al. (2017)). Further, Lam et al. (2019) suggest
that by using microwave heating when producing the bers, the energy
consumption can decrease signicantly. Hermansson et al. (2019)
looked into the environmental impacts of recycled carbon bers and
carbon bers produced from lignin by means of a meta-analysis of life
cycle assessment (LCA) results and found that both were promising
routes for decreasing the environmental impacts of CFRP. Changes in
environmental impacts for carbon bers produced using microwave
heating have, however, not been assessed previously.
This study assessed the future potential environmental impacts of
future use of CFRPs and GFRPs in vehicles using LCA. None of the
technology routes mentioned above have been implemented at an in-
dustrial scale today, which is why a future oriented LCA approach is
needed. Such LCAs are often referred to as prospective LCAs. Arvidsson
et al. (2018 p. 1287) dene prospective LCAs as “studies of emerging
technologies in early development stages, when there are still oppor-
tunities to use environmental guidance for major alterations”. When
conducting prospective LCAs, scenario methods can be used to develop
plausible futures to be assessed (Pesonen et al., 2000). This can entail
exploring not only various considered or conceivable technical changes
that technology developers can engage in, i.e., the foreground system,
but also changes to surrounding systems, such as energy systems and
markets of different materials, i.e., the background system, separately or
in combination.
The overall purpose of this study was to assess if and under which
conditions the use of CFRP in vehicles could have a lower environmental
impact than the conventional lightweighting material, GFRP. This was
* Corresponding author.
E-mail address: frida.hermansson@chalmers.se (F. Hermansson).
Contents lists available at ScienceDirect
Resources, Conservation & Recycling
journal homepage: www.elsevier.com/locate/resconrec
https://doi.org/10.1016/j.resconrec.2022.106234
Received 20 July 2021; Received in revised form 3 December 2021; Accepted 12 February 2022

Resources, Conservation & Recycling 181 (2022) 106234
2
done by assessing different technology development routes both sepa-
rately and in combination, as some are likely to happen at the same time,
by means of explorative scenarios in LCA. This study aims to explore
windows of opportunity for decreasing the environmental impacts of
CFRP and to assess which development routes seem the most promising.
Other studies have previously used LCA to compare the environmental
impacts from using CFRP or GFRP in vehicles: Witik et al. (2011)
compared the environmental impacts from using different lightweight
polymer composites to steel and magnesium in vehicles. They concluded
that some materials with a larger lightweighting potential, such as CFRP
and magnesium, can have increased burdens from the production phase
which could make them undesirable from a life cycle perspective.
Overly et al. (2002) compared the environmental impacts of different
lightweight materials to steel in vehicles. Their results showed that CFRP
is environmentally preferable in most categories, primarily because
CFRP has the largest weight reduction potential. As the conclusions
regarding the environmental performance of CFRP in vehicles differ
between these studies, it illustrates the importance of further assessing
the environmental impacts of these materials to explore under which
conditions the use of CFRP is environmentally benecial. This study
does that and differs from previous LCAs by 1) having a prospective
approach, using explorative scenarios to assess the future production of
GFRP and CFRP following different development routes, and 2) by
comparing the resulting environmental impact for different technology
development routes to identify which one decreases the environmental
impact of CFRP the most compared to that of GFRP. Note that the
outcome of a prospective or future-oriented assessment should be seen
primarily as a contribution to decision-making in technology develop-
ment (Villares et al., 2017). Consequently, any results presented in this
paper should merely be viewed as an indication about what could
happen under different technological and societal developments and be
used as guidance for, e.g., future material development studies.
2. Background
2.1. Fiber production and composite manufacturing
The production of glass bers and carbon bers differs signicantly,
both in terms of raw materials used and in terms of processing tech-
nology. Glass bers are produced from glass that is melted in a furnace
and then travels through a channel out to different forehearths after
which the bers are formed (Stickel and Nagarajan, 2012). Carbon -
bers, on the other hand, are (usually) produced from polyacrylonitrile
(PAN), a fossil-based polymer, where the polymer is rst wet spun into a
precursor ber before being turned into a carbon ber. The trans-
formation to carbon ber is then done in a series of steps including
thermosetting in an oxidizing environment, carbonization in an inert
environment, and, nally, treatment to give the ber surface the right
properties (Das, 2011).
After the bers have been produced, the composites can be manu-
factured. This is done by arranging the bers in an application-specic
way and adding a polymer matrix. The composites are then formed
using e.g., injection molding, compression molding, or resin transfer
molding.
2.2. Technology development routes
This study was part of the Lignin Based Carbon Fibres for Composites
project (LIBRE, 2016). The goals of the project included to develop
lignin-based carbon bers for composites and to reduce the energy
consumption and associated emissions by using microwave heating
technologies, which is why these routes were chosen to be included in
this study. Moreover, Hermansson et al. (2019) found that the recycling
of composites and the subsequent recovery of the bers is a promising
route for decreasing the environmental impacts of CFRP, and therefore
this route was also included. In addition to these three technology
development routes, which are described in more detail in Sections
2.2.1-2.2.3, factors in the surrounding world that could inuence the
future environmental impact of the composites were also explored, as
further described in Section 3.1.
2.2.1. Using bio-based raw materials in ber production
An alternative raw material to PAN in carbon ber production is
lignin. Lignin is the world’s most abundant aromatic polymer and is
found in most terrestrial plants. It is estimated that 15% to 40% of the
plants’ dry weight is constituted by lignin, where it provides structural
integrity (Ragauskas et al., 2014). Today, lignin is mainly used for in-
ternal energy use in pulp mills and bioreneries. However, there are
possibilities for extracting lignin also for other uses (see e.g. Modahl
et al. (2015) and Culbertson et al. (2016)). One such potential use is for
producing carbon bers (see e.g. the LIBRE (2016) project). The pro-
duction of lignin-based carbon bers roughly follows the same produc-
tion process as described for PAN-based carbon bers in Section 2.1.
There are, however, two major differences in the processing: 1) lignin
can sometimes be blended with another polymer before being spun into
a precursor ber (Das, 2011) to reduce brittleness and to improve
thermoplastic behavior (Collins et al., 2019) which is not required for
PAN; and 2) the PAN precursor ber is spun by means of wet spinning,
which requires solvents, while the lignin-based precursor ber can be
spun by means of melt spinning (Das, 2011). The use of lignin instead of
the traditional raw material PAN does not only provide a renewable raw
material source, but the lignin also has some other inherent properties
that, in theory, make it suitable for carbon ber production: the large
content of aromatic compounds and the oxygenated nature of lignin may
reduce energy use in the carbonization and stabilization steps compared
to PAN (see e.g. Das (2011)). Using lignin as a raw material has previ-
ously been shown to be a possibility for decreasing the environmental
impact of carbon bers and carbon ber composites (see e.g. Das (2011),
Janssen et al. (2019), and Hermansson (2020)).
2.2.2. Microwave heating
One way to decrease energy consumption during carbon ber pro-
duction is the use of microwave technology instead of traditional fur-
naces. As an example, Lam et al. (2019) used microwave pyrolysis to
turn bamboo into carbon bers. They claim that the use of microwave
technology could lower the energy use in the carbon ber production
from bamboo bers by more than 90% compared to conventional py-
rolysis using furnaces due to a faster heating rate and a shorter pro-
cessing time.
2.2.3. Recycling of composites with the recovery of bers
The third technical route for decreased environmental impacts is the
recycling of the composites with the recovery and reuse of the bers.
There are three main types of recycling methods for ber reinforced
plastics: mechanical recycling, thermal recycling, and chemical recy-
cling (Yang et al., 2012). The mechanical recycling method is the most
mature composite recycling method and involves milling the composite
into a powder. The recovered material can then be used as, for example,
a ller (Zhang et al., 2020). In thermal recycling, high temperatures are
used to separate the polymer from the bers, and the materials are
degraded and recovered to a varying degree depending on the specic
method used (Yang et al., 2012). The chemical recycling method
removes the polymer matrix by using organic or inorganic solvents to
liberate the bers (Yang et al., 2012), and generally produces clean and
long bers (Zhang et al., 2020). Often in LCAs, the higher the quality of
recovered material, the better the environmental impact, as this can
offset the production of high quality materials in the next life cycle
(Hermansson et al., 2019). This means that thermal and chemical
recycling would likely be the most benecial from an environmental life
cycle perspective, depending on the magnitude of impacts from the
recycling process. Note, however, that recycling can be modelled in
different ways in LCA; this is further discussed in Section 3.1.
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
3
3. Methodology
3.1. Life cycle assessment goal and scope
The goal of this study was to assess the potential impacts of the future
use of CFRP and GFRP in vehicles with the overall intention of exploring
if, and under what conditions, CFRP can outcompete GFRP environ-
mentally. Data were as much as possible collected within the LIBRE
(2016) project and supplemented with literature data when needed.
Calculations and details for the modeling can be found in the Supple-
mentary material.
The functional unit employed in this study was the service provided
by one car component with low structural integrity requirements, rep-
resented by a pair of car mirror brackets. The car component was
assumed to be used over 100 000 km distance driven regardless of being
made of GFRP or CFRP. The weight of the pair of GFRP car mirror
brackets was 0.24 kg and the material composition was 40% bers and
60% polyamide (PA). The weight of the pair of CFRP car mirror brackets
was 0.19 kg and the material composition was 20% ber and 80% PA.
With further development of the design and of the material, the weight
of the CFRP car mirror bracket could possibly be decreased further,
which was therefore assessed in a sensitivity analysis.
All modeling was done using OpenLCA v1.10, and Ecoinvent APOS
3.3 (Wernet et al., 2016) was used as a data source if nothing else is
stated. All production, use, and end-of-life treatment was assumed to
take place in Germany and all transportation of materials has been
excluded from the assessment. Fig. 1 shows the basic outline of the
technical system under assessment. The main difference between the
GFRP and the CFRP manufacturing processes is the ber production, as
described in Section 2.1.
This study assesses climate impact using the IPCC 2013 methodology
and energy use using the cumulative energy demand (CED) methodol-
ogy as provided by Ecoinvent 3.3 (Wernet et al., 2016), as well as
resource depletion using the crustal scarcity indicator (CSI) method
developed by Arvidsson et al. (2020). Climate impact was chosen as it is
strongly connected to the emissions from the energy used in the carbon
ber production, but also since it correlates well with several other
impact categories, such as eutrophication, acidication, and photo-
chemical ozone creation potential (Janssen et al., 2016). Energy use is
an important parameter in most production processes and vehicle use
phases and is often the reason for lightweighting efforts. The resource
depletion was considered because both glass bers and PAN-based
carbon bers are produced using fossil raw materials, and this is one
way to shed light on resource related challenges.
In this assessment, we explore different development routes for CFRP
and GFRP in vehicles and compare these to a base case of GFRP and
CFRP produced using today’s available technology. We explore three
development routes related to ber production and composite
manufacturing: 1) using bio-based raw materials (lignin) in carbon ber
production, 2) using microwave heating in carbon ber production, and
3) recycling of composites with recovery of bers (for both glass and
carbon bers). In addition, some possible changes to the background
system were explored. Hermansson (2020) identied the demand for
lignin (and hence, price of lignin) as well as the energy mix in the energy
system as inuential for the climate impact of carbon ber production,
which is why these two factors were considered. Additionally, this study
explores the shift from vehicles with internal combustion engines (ICE)
to battery electric vehicles (BEV).
The PAN-based carbon ber production is based on a version of the
PAN-precursor ber production dataset provided by European Platform
on Life Cycle Assessment (2018) which was modied to be compatible
with the impact assessment methods of this study (see Hermansson et al.
(2022) for details) and data collected within the LIBRE (2016) project.
The bio-based carbon ber production is based on an updated version of
what was published in Hermansson (2020), and we assume that the
lignin-based and PAN-based carbon bers have the same quality. The
lignin-based bers are assumed to be produced from 50% bio-based
polyurethane (bio-PU) and 50% Organosolv lignin (see Culebras et al.
(2018) for the properties of different bers produced from lignin and
bio-PU blends). The bio-PU production was approximated by combining
polyol production based on data from Fridrihsone-Girone (2015) with a
modied Ecoinvent dataset on polyurethane production. The lignin
production data were based on data for an Organosolv mill provided by
Moncada et al. (2018).
Lignin is always the product of a multi-output process, which means
that the impacts of the lignin-generating mill need to be allocated be-
tween the outputs, and the prospective nature of this study makes the
choice of allocation basis challenging (see Hermansson et al. (2020) for
more information on how lignin’s climate impact could change over
time). In this study, we chose to allocate the impacts of the Organosolv
mill on an economic basis. A possible future development is that the
demand for lignin increases, and thus also its price in comparison to that
of other co-products from the mill. To illustrate such a situation, the
main-product-bears-all-burden approach of Sandin et al. (2015) was
used to represent a situation where the lignin price is high compared to
other co-products of the biorenery. This extreme assumption can be
seen as a worst-case scenario to test the importance of lignin’s market
development for the CFRPs’ environmental impact.
The material yield in the stabilization and carbonization is assumed
to be 50% for the bio-based carbon bers which is in line with what is
suggested by Das (2011). Note that the blending with bio-PU can in-
uence the material yield to become lower than that (see Culebras et al.
(2018)). It is also assumed that the material yield in stabilization and
carbonization is 50% also for the PAN-based carbon bers. The energy
carrier in the ber stabilization and carbonization is assumed to be
electricity and nitrogen is used to create an inert environment. Carbon
bers are traditionally produced using furnaces but could be produced
by means of microwave heating. In this study, we assume that the use of
microwave heating can reduce the energy consumption for the stabili-
zation and carbonization by 93.5% compared to using conventional
furnaces. This value is based on the average difference in energy con-
sumption between using a furnace and microwave pyrolysis for trans-
forming a bamboo ber to a carbon ber as reported by Lam et al.
Fig. 1. The conceptual owchart of the technical system. The vehicle
manufacturing (gray box) is assumed to be the same for both the CFRP and the
GFRP brackets and is therefore not further considered.
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
4
(2019). It is assumed that the nitrogen consumption and material yield
stay the same regardless of carbon ber production method.
The bers are considered to be chopped before being added into the
thermoplastic polymer matrix (any impacts related to chopping and
mixing have been excluded as they are deemed to be negligible). The
mirror brackets are nally formed by means of injection molding. The
resulting composite is assumed to be of relatively low structural integ-
rity, thus suitable for car components with lower requirements such as
car mirror brackets.
When using CFRP mirror brackets instead of GFRP mirror brackets,
the vehicle becomes lighter. This results in a lower fuel consumption
over the vehicle’s life cycle. This was calculated using the rationale used
by Del Pero et al. (2017). The fuel savings from the lightweighting of the
car when switching from a car mirror bracket produced from GFRP to
one from CFRP corresponds to 0.092 liters in an ICE vehicle and 0.345
kWh in a BEV throughout the mirror brackets’ life cycle (i.e., 100 000
km).
The end-of-life for the composites was in the base case assumed to be
a landll as this is the option that is currently practiced. When recycled,
it is assumed that the composite is sent to pyrolysis, which uses 30 MJ/
kg CFRP composite (Witik et al., 2013), and we assume the same value
for GFRP. Note that there are some emissions (of for example carbon
dioxide) from the pyrolysis process, but due to lack of data, only emis-
sions associated with the energy needed for the process were included in
this study. The pyrolysis process is assumed to result in carbon bers
with a tensile strength reduction of 18% compared to primary bers
(Pickering et al., 2015), which is approximately in line with what is
reported by Irisawa et al. (2021), and depends on process conditions
such as temperature and time. The tensile strength of the glass bers was
assumed to be reduced by 50% (Pickering, 2006), which is slightly less
than reported in Rahimizadeh et al. (2020). Both values for tensile
strength reduction used in this study are for the recovery of bers from
composites using uidized beds but are here used as a proxy value for a
general pyrolysis process. It is assumed that the polymer is recovered as
an oil from the pyrolysis process (Cunliffe et al., 2003). This oil is
assumed to be equivalent in function and impacts to petroleum and it is
assumed that the whole polymer matrix is fully degraded to an oil.
When the composite mirror brackets are recycled, another allocation
problem will arise, and burdens (such as from primary material pro-
duction) and benets (such as from recovered bers and oil) from
recycling need to be distributed between the life cycles of the rst and
second products. In this study, we use two different allocation ap-
proaches to distribute the environmental impacts between the products:
the end-of-life recycling approach and the cut-off approach, both
adapted for composite recycling as suggested by Hermansson et al.
(2022) and using a mass basis for allocating the impacts from the
composite recycling process between the bers and the polymer. The
inclusion of both allocation approaches was done to capture the ex-
tremes in common approaches (Hermansson et al., 2022). The
end-of-life recycling approach, on the one hand, considers the amount of
material being recycled. In this study, we assumed that the composites
are fully recycled after use, meaning the recycling rate of the materials
leaving the system is 100%. The recovered materials substitute the
production of primary materials, and the composite is therefore given a
credit for the avoided production of bers and polymer. The credit for
the bers is adjusted using a quality correction factor based on the
relative tensile strength reduction (as suggested by Hermansson et al.
(2022), and the polymer is given a credit for the avoided production of
petroleum, as it is degraded to a comparable oil during pyrolysis. The
cut-off approach, on the other hand, considers the amount of recycled
material being used in the production. Using recycled bers in com-
posite production today is very rare. However, as composite recycling
technology matures, this is likely to change. For the recycling options in
this study, it was assumed that 50% of the incoming glass bers and 82%
of the incoming carbon bers were from recycled material and that these
come from composites recycled by means of pyrolysis. These values
were chosen to account for the difference in need of adding primary
materials to compensate for quality losses. It was assumed that the
polymer used in the composite production is 100% primary material. It
is possible that the polymers recycled from the composites are used as an
input in a second composite in the same way as we assume for the bers,
but due to lack of data for any processing needed for the pyrolysis oil to
become a comparable polymer again, this was not considered.
To test the robustness of the assumptions made, sensitivity analyses
were done for: recycling rates, the bers’ tensile strength reduction in
recycling, the energy consumption during pyrolysis, the energy con-
sumption for microwave heating, as well as additional lightweighting of
the CFRP mirror brackets compared to GFRP mirror brackets. The results
of the sensitivity analysis are discussed in Section 4.3.
3.2. Generating future scenarios
The technology development routes described in Section 3.1 can also
be combined into consistent scenarios. This was done by following the
method used by Langkau and Erdmann (2021) who assessed the envi-
ronmental impacts of the future supply of rare earth metals. In short,
sub-scenarios were created based on different variations in the life cycle
inventory corresponding to the different development routes (now the
varied inventory data will be called parameters). To limit the number of
possible combinations of sub-scenarios, the interrelationships between
these were assessed and only the sub-scenarios most likely to be strongly
connected were combined into future scenarios and assessed further.
The parameters used in the scenario development were divided into
parameters inuencing the foreground system or the background system
and are found in the Supplementary material. The parameters for the
allocation-related variations were all based on changes in the back-
ground system: The parameter related to the demand of lignin will in-
uence the allocation of impacts between the products of the lignin-
generating process. The environmental legislation parameter accounts
for that different recycling allocation approaches (here, the cut-off and
the end-of-life recycling approaches) provide different incentives (Her-
mansson et al., 2022) and therefore reect different norms and values
(Ekvall and Tillman, 1997; Frischknecht, 2010).
To map how the different parameters, and consequently the sub-
scenarios, interrelate, a causal loop diagram (De Vries, 2012) was
made. Based on these interrelationships, the sub-scenarios were subject
to a cross consistency check (the basics of such a procedure are for
example described in Ritchey (2018)) in order to reduce the amount of
possible combinations to only the most plausible ones. Both the causal
loop diagram and the cross-consistency check can be found in the Sup-
plementary material.
The most plausible combinations of sub-scenarios were then com-
bined into overall scenarios. The cross-consistency check resulted in
three different overall scenarios which are found in Table 1. In essence,
Scenario 1 would mirror a future with a strong focus on the bioeconomy
(focusing on decreasing emissions throughout the system and using bio-
based materials), Scenario 2 would have a strong focus on a circular
economy (focusing on recycling and reusing materials and decreasing
waste generation), and Scenario 3 would be a combination of the two
rst - a future with a strong focus on a ‘circular bioeconomy’. Note that
these classications are rough and based on the groupings of which sub-
scenarios that were deemed to correlate the most with each other.
We made the choice to consider only the most extreme situation for
all scenarios. This choice was based on the argument that the balance
between technologies is hard to predict, so for clarity reasons, when
presenting the results, this assessment is binary in the sense that it is
either 100% or 0% of the different sub-scenarios. This means, e.g., that
there is 100% of bio-based carbon bers that are only used in BEVs in
Scenario 1, that all carbon bers are PAN-based and used only in con-
ventional vehicles and fully recycled in Scenario 2, and that 100% of the
carbon bers are bio-based, used in only BEVs and completely recycled
in Scenario 3. In the future, there would of course be a mix, with some
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
5
sub-scenarios dominating.
4. The future environmental impacts of composites in vehicles
4.1. What would it take for CFRP to have a lower environmental impact
than GFRP in vehicles?
Fig. 2 shows the inuence the considered development routes could
have on climate impact, energy use, and resource depletion of car mirror
brackets made from GFRP or CFRP as described in Section 3.1, if
implemented separately.
Results show that GFRP mirror brackets always have a lower climate
impact than CFRP mirror brackets except for when the composites are
being recycled or when a fossil-carbon lean energy mix is assumed. The
generally higher climate impact of the CFRP car mirror brackets is pri-
marily due to the very energy intensive carbon ber production process.
When using our modeling approach, the use of gasoline in an ICE vehicle
results in a credit for lightweighting corresponding to approximately the
impacts of manufacturing the composite which reduces the climate
impact of the CFRP mirror brackets to some extent, but generally not
enough for it to be competitive to GFRP. The lightweighting credit be-
comes even smaller when the brackets are used in a BEV, indicating that
lightweighting of electric vehicles by means of CFRP would be less
useful for decreasing the life cycle climate impact. The lower climate
impact of CFRP mirror brackets compared to GFRP mirror brackets in
Fig. 2a) are primarily dependent on some modeling choices, namely the
allocation approach used in the recycling modeling and the substituted
products, as well as the way the future fossil-carbon lean energy mix for
the PAN-bers was modelled (see the Supplementary material for
details).
Fig. 2b) shows that the life cycle energy use is only lower for CFRP
mirror brackets when the composites are being recycled as the energy
use is not inuenced to the same extent by a transition to a fossil-carbon
lean energy mix. The main reason for this is, just as for climate impact,
the carbon ber production process. The energy use of CFRP mirror
brackets is also higher than for GFRP mirror brackets even if the bers
are produced from biobased raw materials, regardless of the price of
lignin or the introduction of microwave heating in ber production. The
lightweighting credit offsets some of the higher energy use of the CFRP
mirror brackets compared to GFRP mirror brackets. However, unlike for
the climate impact, switching from using the brackets in a BEV instead of
a vehicle with ICE does not inuence the net energy use signicantly.
Fig. 2c) shows that the resource depletion is signicantly lower for
the CFRP mirror brackets than for the GFRP mirror brackets for all
development routes. This is because of the glass ber production, where
the production of boric acid used in the glass ber production is
responsible for almost 70% of the total resource depletion of the GFRP
mirror brackets, which is primarily caused by a ow of colemanite.
Colemanite is one of four major borate minerals that in total account for
90% of the global industry use of borate minerals, and more than 75% of
the global consumption is for ceramics, detergents, fertilizers, and glass
(U.S. Geological Survey, 2021). As glass is already a major application
for borate minerals, and with an increased global interest in light-
weighting of vehicles, this indicates that the resource depletion may be a
major problem related to the future manufacturing of berglass.
4.2. What could happen in different futures?
Fig. 3 shows the resulting climate impact, energy use, and resource
depletion for a pair of car mirror brackets produced from either GFRP or
CFRP for the base case (representing today) and in three different sce-
narios representing three different futures: bioeconomy, circular econ-
omy, and circular bioeconomy (see descriptions in Section 3.2).
In Scenario 1, with a focus on bioeconomy, the climate impact of the
GFRP and CFRP brackets is approximately the same. This is primarily a
consequence of the energy background system. Any reduction in elec-
tricity use in the carbon ber production from using microwave heating
in a fossil carbon-lean energy mix will have less of an inuence than a
reduction in a system with a fossil carbon-rich energy mix. For the same
reason, the effect of lightweighting in a future with a fossil carbon-lean
energy mix and electric vehicles will also be signicantly smaller. The
life cycle energy use of the CFRP brackets, on the other hand, is signif-
icantly higher than for the GFRP brackets in Scenario 1. In fact, the
difference in energy use between the two materials is even higher than
for the today’s scenario. This is because the considered price increase for
lignin leads to it being allocated all the impacts of the mill. Note that the
employed energy use assessment method does not differentiate between
renewables and non-renewables in the energy system. Consequently, the
shift to biobased bers will not reward e.g. the lignin production process
for having a high share of renewables (about 90%). This highlights the
need in some contexts for assessing renewable and non-renewable en-
ergy use separately to avoid the risk of generating misleading results,
especially in cases and for materials where the energy use is the domi-
nating contributor to impacts. The resource depletion, on the other
hand, is signicantly lower for the CFRP mirror brackets than for the
GFRP brackets. This is, again, connected to the use of boric acid in the
glass ber production (see Section 4.1) which is not inuenced by
changes in the background system.
In Scenario 2, which has a circular economy focus, the CFRP mirror
brackets have a lower net climate impact, energy use, and resource
depletion than the GFRP mirror brackets. The lower resource depletion
of CFRP is still connected to the use of boric acid in the glass ber
production. The lower climate impact and energy use are primarily
dependent on the recycling, and how it was modelled; the end-of-life
recycling approach includes credits for the avoided production in the
next life cycle. This credit is higher for carbon bers than for glass bers,
Table 1
The three constructed scenarios for the assessment. *) only inuences carbon ber reinforced polymers (CFRPs); all other developments inuence both CFRPs and glass
ber reinforced polymers (GFRPs).
Parameter settings in foreground system Parameter settings in background system
Scenario 1:
Bioeconomy
- Fibers are produced from bio-based raw materials*
- Fibers are produced using microwave heating*
- Composites are sent to landll
- Price of lignin increases*
- Energy mix transitions towards being fossil-carbon lean
- Composites are used in a BEV
1
- There is legislation to reduce extraction of fossils from the ecosphere
Scenario 2:
Circular economy
- Fibers are produced using fossil-based raw materials
- Fibers are produced using conventional technologies
- Composites are recycled and materials recovered
- Price of lignin remains the same*
- Energy mix stays constant
- Composites are used in vehicle with ICE
2
- There is legislation to promote recycling and recovery of materials; end-of-life recycling approach
Scenario 3:
Circular
bioeconomy
- Fibers are produced using bio-based raw materials*
- Fibers are produced using microwave heating*
- Composites are recycled and materials recovered
- Price of lignin increases*
- Energy mix transitions towards being fossil-carbon lean
- Composites are used in a BEV
1
- There is legislation to reduce extraction of fossils from the ecosphere; cut-off allocation approach
1
Battery electric vehicle.
2
Internal combustion engine.
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
6
partly because the impacts of producing primary carbon bers is higher,
but also because the carbon bers are assumed to retain a higher rate of
tensile strength than the glass bers. In addition to this, this is the sce-
nario where the car mirror brackets are still considered to be used in
conventional vehicles with ICEs, meaning that the lightweighting credit
given to the CFRP car mirror brackets for the avoided use of petroleum-
based fuel consumption is large.
In Scenario 3 (circular bioeconomy focus), the climate impacts of the
CFRP and GFRP car mirror brackets are practically the same, whereas
the energy use for the CFRP brackets is slightly lower than for the GFRP
brackets. The reason for this is the same as for Scenario 1, that the
climate impact for the car mirror brackets is strongly connected to the
energy mix. When the energy system has transitioned towards being
fossil carbon lean, the difference in climate impact between the GFRP
and CFRP brackets is decreased signicantly regardless of there being a
large difference in energy use or not. In addition to this, the credit for
avoided fuel use is decreased due to the fossil carbon lean energy mix.
The difference in life cycle energy use between the brackets is primarily
related to the recycling, where the input of recycled material is higher
for CFRP than for GFRP. The resource depletion remains higher for the
GFRP car mirror brackets for the same reason as before: the colemanite
ow in the boric acid production. This is however decreased to some
extent compared to for Scenario 1 due to avoided production of some of
the glass bers when the composite is being recycled.
Fig. 2. The inuence of the considered development routes described in Section 3.1 on the a) climate impact, b) energy use, and c) resource depletion of a pair of car
mirror brackets produced from carbon ber reinforced polymers (CFRP) or glass ber reinforced polymers (GFRP). The black bar indicates the net impact and BEV is
short for battery electric vehicle.
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
7
Of all scenarios and indicators used in this study, it is only Scenario 1
(Bioeconomy) for energy use that does not create a situation that gives an
advantage to the CFRP over GFRP. This means that CFRPs are quite likely
to become more environmentally competitive to GFRPs in the future and,
in particular, if recycling technologies for composites are implemented.
4.3. Assessing the environmental impacts of the future use of composites
in vehicles using life cycle assessment
In this paper we explore different routes that the development of
carbon ber composite manufacturing could take. These routes are
Fig. 3. The a) climate impact, b) energy use, and c) resource depletion of a pair of car mirror brackets produced from either carbon ber reinforced polymers (CFRP)
or glass ber reinforced polymers (GFRP) today and in three different futures. The black bar indicates the net impact.
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
8
explored with a focus on plausible futures, rather than trying to predict
the actual future impacts of CFRPs. This is done to identify which
technology development routes are more promising than others and to
identify any windows of opportunity for future material development.
While our results seen individually may not be realistic, we argue that
environmental impacts will likely end up somewhere in the range of the
results presented in Figs. 2 and 3, and in particular if technology de-
velopers allow themselves to be guided by the conclusions.
It is important to consider that all results presented in this paper are
highly dependent on the methodological choices made, primarily those
connected to the choice of allocation approaches in lignin production
and composite recycling. Hermansson et al. (2020) showed that the
choice of allocation approach for lignin production has a signicant
effect on the resulting impact for lignin, and consequently also for
lignin-based products. In this study, we used the
main-product-bears-all-burden approach to approximate a future where
lignin is the dominating and/or most expensive product of the Orga-
nosolv mills in Scenarios 1 and 3. However, it should be noted that using
another allocation approach would change the environmental impacts
of the bio-based bers. Further, the recycling of the composites is
handled by the end-of-life recycling approach in Scenario 2 and the
cut-off approach in Scenario 3. Scenario 1 did not include any recycling,
which is why no allocation between primary and secondary products
was needed. The recycling allocation approaches suggested by Her-
mansson et al. (2022) include allocation of the pyrolysis’ impacts be-
tween the bers and the polymer. In this study, this is done on a mass
basis; another basis, such as economic, would have given other results.
An economic allocation basis is however challenging to use in pro-
spective studies (Hermansson et al., 2020) which is why a mass basis was
chosen.
As the end-of-life recycling approach provides incentives to recycle
and provide recycled materials with high quality (as further discussed by
Hermansson et al. (2022) we deemed it suitable in a context with strong
focus on circular economy, such as in Scenario 2. In Scenario 3, the focus
is both on circular economy and on bioeconomy, thus likely decreasing
the extraction of fossils from the ecosphere. In this situation, the cut-off
approach was instead considered more representative, as it is in line
with the ‘strong sustainability’ idea, or the unwillingness to trade off
resource extraction from the ecosphere for other values (see Frisch-
knecht (2010) for how different allocation approaches relate to different
views on sustainability). We suggest that the choice of allocation
approach should be a part of the scenario development, where different
allocation approaches are connected to different environmental con-
cerns and future market developments. This can be done by more
consciously considering how allocation approaches depend on how the
background system develops when constructing the scenarios.
A currently unavoidable weakness in this LCA is the fact that the
modeling of the future routes is based on assumptions and literature
data. The results of the sensitivity analysis are summarized in Table 2
and are found in detail in the Supplementary material. Table 2 shows
that the results are the most sensitive to the assumptions on energy
consumption in the pyrolysis process and the microwave heating pro-
cess. Table 2 also shows that the results are the least sensitive to as-
sumptions on recycling rate and the quality degradation of the bers in
pyrolysis. The results of the sensitivity analysis also highlight the
importance of not only substituting GFRP with CFRP on a one-to-one
basis, but to also take advantage of any superior mechanical proper-
ties of the carbon bers and to carefully assess the possible development
of the design of the component.
Another limitation in this assessment of the future environmental
impact of composites in vehicles is that the transition to a low carbon
energy system in Scenarios 1 and 3 is done by approximations and not in
a fully consistent way. This is primarily due to limitations in the
modeling software used, the way some datasets are constructed, and the
low data availability. However, it is unlikely that the outcomes of the
study would change signicantly with more consistent background
modeling than described in the Supplementary material, as the main
impacts are primarily related to direct energy use. Other software with
better accommodation for changing the background system could be
benecial to use in future studies (see for example Joyce and Bj¨
orklund
(2021) and Steubing et al. (2020)). Further, more (transparent) data on,
for example, bio-polymer production would also improve the trust-
worthiness of the results.
5. Conclusions
This paper assesses the potential life cycle climate impact, energy
use, and resource depletion of future GFRP and CFRP use in vehicles, to
shed light on if CFRP could have a lower impact than GFRP. This was
done by assessing different technology routes separatly, but also
grouped into different future scenarios. Results show that the most
promising individual route for decreasing the relative environmental
impact of CFRP car mirror brackets includes recycling of the composites
with recovery of the bers. Further, CFRP shows great potential to have
a lower environmental impact than GFRP in all three different futures
assessed, but this is highly dependent on assumed developments in the
background system such as a high price of lignin, increased incentives
for recycling, and increased incentives for reducing extraction from the
eco-sphere. If the considered scenarios represent the future, we can
conclude that CFRPs are likely to have a lower environmental impact
than GFRPs in these kinds of applications in the future.
CRediT authorship contribution statement
Frida Hermansson: Conceptualization, Methodology, Investigation,
Writing – original draft, Writing – review & editing. Sara Heimersson:
Methodology, Investigation, Writing – review & editing. Matty Jans-
sen: Methodology, Supervision, Writing – review & editing. Magdalena
Svanstr¨
om: Methodology, Supervision, Writing – review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing nancial
interests or personal relationships that could have appeared to inuence
the work reported in this paper.
Data availability statement
The authors declare that primary data for carbon ber production
cannot be shared due to condentiality. Data supporting all other results
can either be found in the article or in the supplementary material.
Acknowledgement
This project has received funding from the Bio Based Industries Joint
Undertaking under the European Union’s Horizon 2020 research and
Table 2
The impact the parameters varied in the sensitivity analysis have on the results.
Low impact indicates a maximum deviation of less than 10%, medium impact
indicates a maximum deviation of between 10 and 30%, and high impact in-
dicates a maximum deviation of more than 30%.
Parameter Impact on LCA result
Climate
impact
Energy
use
Resource
depletion
Recycling rate changes Low Low Low
Quality of recovered bers Low Low Low
Pyrolysis energy consumption Medium Medium High
Microwave heating energy
consumption
Medium Medium High
Further mass reductions Medium Medium Medium
F. Hermansson et al.

Resources, Conservation & Recycling 181 (2022) 106234
9
innovation program under grant agreement No 720707. The authors
would like to thank the members of the LIBRE consortium for providing
data to this study.
Supplementary materials
Supplementary material associated with this article can be found, in
the online version, at doi:10.1016/j.resconrec.2022.106234.
References
Arvidsson, R., S¨
oderman, M.L., Sand´
en, B.A., Nordel¨
of, A., Andr´
e, H., Tillman, A.-.M.,
2020. A crustal scarcity indicator for long-term global elemental resource assessment
in LCA. Int. J. Life Cycle Assess. 25 (9), 1805–1817. https://doi.org/10.1016/j.
jclepro.2017.04.01310.1007/s11367-020-01781-1.
Arvidsson, R., Tillman, A.M., Sand´
en, B.A., Janssen, M., Nordel¨
of, A., Kushnir, D.,
Molander, S., 2018. Environmental assessment of emerging technologies:
recommendations for prospective LCA. J. Ind. Ecol. 22 (6), 1286–1294. https://doi.
org/10.1111/jiec.12690.
Collins, M.N., Nechifor, M., Tanas˘
a, F., Z˘
anoag˘
a, M., McLoughlin, A., Str´
o˙
zyk, M.A., ...,
Teac˘
a, C.-.A., 2019. Valorization of lignin in polymer and composite systems for
advanced engineering applications–a review. Int. J. Biol. Macromol. https://doi.org/
10.1016/j.ijbiomac.2019.03.069.
Culbertson, C., Treasure, T., Venditti, R., Jameel, H., Gonzalez, R., 2016. Life cycle
assessment of lignin extraction in a softwood kraft pulp mill. Nord. Pulp Pap. Res. J.
31 (1), 30–U247. https://doi.org/10.3183/npprj-2016-31-01-p030-040.
Culebras, M., Beaucamp, A., Wang, Y., Clauss, M.M., Frank, E., Collins, M.N., 2018.
Biobased structurally compatible polymer blends based on lignin and thermoplastic
elastomer polyurethane as carbon ber precursors. ACS Sustain. Chem. Eng. 6 (7),
8816–8825. https://doi.org/10.1021/acssuschemeng.8b01170.
Cunliffe, A.M., Jones, N., Williams, P.T., 2003. Recycling of bre-reinforced polymeric
waste by pyrolysis: thermo-gravimetric and bench-scale investigations. J. Anal. Appl.
Pyrolysis 70 (2), 315–338. https://doi.org/10.1016/S0165-2370(02)00161-4.
Das, S., 2011. Life cycle assessment of carbon ber-reinforced polymer composites. Int. J.
Life Cycle Assess. 16 (3), 268–282. https://doi.org/10.1007/s11367-011-0264-z.
De Vries, B.J.M., 2012. Sustainability Science. Cambridge University Press, New York,
United States.
Del Pero, F., Delogu, M., Pierini, M., 2017. The effect of lightweighting in automotive
LCA perspective: estimation of mass-induced fuel consumption reduction for
gasoline turbocharged vehicles. J. Clean. Prod. 154, 566–577. https://doi.org/
10.1016/j.jclepro.2017.04.013.
Ekvall, T., Tillman, A.-.M., 1997. Open-loop recycling: criteria for allocation procedures.
Int. J. Life Cycle Assess. 2 (3), 155. https://doi.org/10.1007/BF02978810.
Elanchezhian, C., Ramnath, B.V., Hemalatha, J., 2014. Mechanical behaviour of glass
and carbon bre reinforced composites at varying strain rates and temperatures.
Procedia Mater. Sci. 6, 1405–1418. https://doi.org/10.1016/j.mspro.2014.07.120.
European Platform on Life Cycle Assessment, 2018. ELCD. Retrieved from: https://eplca.
jrc.ec.europa.eu/ELCD3/index.xhtml.
Fridrihsone-Girone, A., 2015. Preliminary Life Cycle Inventory of Rapeseed Oil Polyols
for Polyurethane Production. J. Renew. Mater. 3 (1), 28–33. https://doi.org/
10.7569/JRM.2014.634136.
Frischknecht, R., 2010. LCI modelling approaches applied on recycling of materials in
view of environmental sustainability, risk perception and eco-efciency. Int. J. Life
Cycle Assess. 15 (7), 666–671. https://doi.org/10.1007/s11367-010-0201-6.
Hermansson, F., 2020. Assessing the Future Environmental Impact of lignin- based and
Recycled Carbon Fibres in Composites Using Life Cycle assessment. (Licentiate of
Engineering Licentiate thesis. Chalmers University of Technology, Chalmers
Reproservice, Gothenburg.
Hermansson, F., Janssen, M., Svanstr¨
om, M., 2020. Allocation in life cycle assessment of
lignin. Int. J. Life Cycle Assess. 25, 1620–1632. https://doi.org/10.1007/s11367-
020-01770-4.
Hermansson, F., Ekvall, T., Janssen, M., Svanstr¨
om, M., 2022. Allocation in recycling of
composites-the case of life cycle assessment of products from carbon ber
composites. Manuscript in Progress.
Hermansson, F., Janssen, M., Svanstr¨
om, M., 2019. Prospective study of lignin-based and
recycled carbon bers in composites through meta-analysis of life cycle assessments.
J Clean Prod 223, 946–956. https://doi.org/10.1016/j.jclepro.2019.03.022.
Irisawa, T., Aratake, R., Hanai, M., Sugimoto, Y., Tanabe, Y., 2021. Elucidation of
damage factors to recycled carbon bers recovered from CFRPs by pyrolysis for
nding optimal recovery conditions. Compos. B. Eng. 218, 108939 https://doi.org/
10.1016/j.compositesb.2021.108939.
Janssen, M., Gustafsson, E., Echardt, L., Wallinder, J., Wolf, J., 2019. Life cycle
assessment of lignin-based carbon bres. In: Paper presented at the 14th Conference
on sustainable development of energy, water and environment systems. SDEWES,
Dubrovnik, 1-6 October 2019.
Janssen, M., Xiros, C., Tillman, A.-.M., 2016. Life cycle impacts of ethanol production
from spruce wood chips under high-gravity conditions. Biotechnol. Biofuels 9 (1),
53. https://doi.org/10.1186/s13068-016-0468-3.
Joyce, P.J., Bj¨
orklund, A., 2021. Futura: a new tool for transparent and shareable
scenario analysis in prospective life cycle assessment. J. Ind. Ecol. https://doi.org/
10.1111/jiec.13115.
Lam, S.S., Azwar, E., Peng, W., Tsang, Y.F., Ma, N.L., Liu, Z., ..., Kwon, E.E., 2019.
Cleaner conversion of bamboo into carbon bre with favourable physicochemical
and capacitive properties via microwave pyrolysis combining with solvent extraction
and chemical impregnation. J. Clean. Prod. 236, 117692 https://doi.org/10.1016/j.
jclepro.2019.117692.
Langkau, S., Erdmann, M., 2021. Environmental impacts of the future supply of rare
earths for magnet applications. J. Ind. Ecol. 25 (4), 1034–1050. https://doi.org/
10.1111/jiec.13090.
LIBRE. (2016). LIBRE-lignin based carbon bres for composites. Retrieved from http://
libre2020.eu.
Meng, F., McKechnie, J., Turner, T., Wong, K.H., Pickering, S.J., 2017. Environmental
aspects of use of recycled carbon ber composites in automotive applications.
Environ. Sci. Technol. 51 (21), 12727–12736. https://doi.org/10.1021/acs.
est.7b04069.
Modahl, I.S., Brekke, A., Valente, C., 2015. Environmental assessment of chemical
products from a Norwegian biorenery. J. Clean. Prod. 94, 247–259. https://doi.
org/10.1016/j.jclepro.2015.01.054.
Moncada, J., Gursel, I.V., Huijgen, W.J., Dijkstra, J.W., Ramírez, A., 2018. Techno-
economic and ex-ante environmental assessment of C6 sugars production from
spruce and corn. Comparison of organosolv and wet milling technologies. J. Clean.
Prod. 170, 610–624. https://doi.org/10.1016/j.jclepro.2017.09.195.
Overly, J.G., Dhingra, R., Davis, G.A., Das, S., 2002. Environmental evaluation of
lightweight exterior body panels in new generation vehicles. Pap. Presented SAE Int
https://www.jstor.org/stable/44718703.
Pesonen, H.L., Ekvall, T., Fleischer, G., Huppes, G., Jahn, C., Klos, Z.S., ..., Wenzel, H.,
2000. Framework for scenario development in LCA. Int. J. Life Cycle Assess. 5 (1),
21. https://doi.org/10.1007/BF02978555.
Pickering, S., Turner, T., Meng, F., Morris, C., Heil, J., Wong, K., Melendi-Espina, S.,
2015. Developments in the uidised bed process for bre recovery from thermoset
composites. In: Paper presented at the 2nd Annual Composites and Advanced
Materials Expo, CAMX 2015. Dallas Convention CenterDallas, United States.
Pickering, S.J., 2006. Recycling technologies for thermoset composite
materials—Current status. Compos Part A Appl. Sci. Manuf. 37 (8), 1206–1215.
https://doi.org/10.1016/j.compositesa.2005.05.030.
Ragauskas, A.J., Beckham, G.T., Biddy, M.J., Chandra, R., Chen, F., Davis, M.F., ...,
Keller, M., 2014. Lignin valorization: improving lignin processing in the biorenery.
Science 344 (6185), 1246843. https://doi.org/10.1126/science.1246843.
Rahimizadeh, A., Tahir, M., Fayazbakhsh, K., Lessard, L., 2020. Tensile properties and
interfacial shear strength of recycled bers from wind turbine waste. Composites,
Part A 131, 105786. https://doi.org/10.1016/j.compositesa.2020.105786.
Ritchey, T., 2018. General morphological analysis as a basic scientic modelling method.
Technol. Forecast. Soc. Change 126, 81–91. https://doi.org/10.1016/j.
techfore.2017.05.027.
Sandin, G., Røyne, F., Berlin, J., Peters, G.M., Svanstr¨
om, M., 2015. Allocation in LCAs of
biorenery products: implications for results and decision-making. J. Clean. Prod.
93, 213–221. https://doi.org/10.1016/j.jclepro.2015.01.013.
Steubing, B., de Koning, D., Haas, A., Mutel, C.L., 2020. The Activity Browser — An open
source LCA software building on top of the brightway framework. Software Impacts
3, 100012. https://doi.org/10.1016/j.simpa.2019.100012.
Stickel, J.M., Nagarajan, M., 2012. Glass ber-reinforced composites: from formulation
to application. Int. J. Appl. Glass Sci. 3 (2), 122–136. https://doi.org/10.1111/
j.2041-1294.2012.00090.x.
U.S. Geological Survey. (2021). Mineral commodity summaries 2021. Retrieved from.
Villares, M., Is¸ıldar, A., van der Giesen, C., Guin´
ee, J., 2017. Does ex ante application
enhance the usefulness of LCA? A case study on an emerging technology for metal
recovery from e-waste. Int. J. Life Cycle Assess. 22 (10), 1618–1633 doi:https://
10.1007/s11367-017-1270-6.
Wernet, G., Bauer, C., Steubing, B., Reinhard, J., Moreno-Ruiz, E., Weidema, B., 2016.
The ecoinvent database version 3 (part I): overview and methodology. Int. J. Life
Cycle Assess. 21 (9), 1218–1230. https://doi.org/10.1007/s11367-016-1087-8.
Witik, R.A., Payet, J., Michaud, V., Ludwig, C., Månson, J.-A.E., 2011. Assessing the life
cycle costs and environmental performance of lightweight materials in automobile
applications. Compos. Part A Appl. Sci. Manuf. 42 (11), 1694–1709. https://doi.org/
10.1016/j.compositesa.2011.07.024.
Witik, R.A., Teuscher, R., Michaud, V., Ludwig, C., Månson, J.-A.E., 2013. Carbon bre
reinforced composite waste: an environmental assessment of recycling, energy
recovery and landlling. Compos Part A Appl. Sci. Manuf. 49, 89–99. https://doi.
org/10.1016/j.compositesa.2013.02.009.
Yang, Y., Boom, R., Irion, B., van Heerden, D.-.J., Kuiper, P., de Wit, H., 2012. Recycling
of composite materials. Chem. Eng. Process. 51, 53–68. https://doi.org/10.1016/j.
cep.2011.09.007.
Zhang, J., Chevali, V.S., Wang, H., Wang, C.-.H., 2020. Current status of carbon bre and
carbon bre composites recycling. Compos B Eng. 193, 108053 https://doi.org/
10.1016/j.compositesb.2020.108053.
F. Hermansson et al.