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Life cycle assessment of carbon fiber-reinforced polymer composites
Abstract
PurposeThe use of carbon fiber-reinforced polymer matrix composites is gaining momentum with the pressure to lightweight vehicles;
however energy intensity and cost remain major barriers to the wide-scale adoption of this material for automotive applications.
This study determines the relative life cycle benefits of two precursor types (conventional textile-type acrylic fibers and
renewable-based lignin), part manufacturing technologies (conventional SMC and P4), and a fiber recycling technology.
Materials and methodsA representative automotive part, i.e., a 30.8-kg steel floor pan having a 17% weight reduction potential with stringent crash
performance requirements, has been considered for the life cycle energy and emissions analysis. Four scenarios—combinations
of the precursor types and manufacturing technologies—are compared to the stamped steel baseline part.
Results and discussionThe analysis finds the lignin-based part made through P4 technology to offer the greatest life cycle energy and CO2 emissions benefits. Carbon fiber production is estimated to be about 14 times more energy-intensive than conventional steel
production; however, life cycle primary energy use is estimated to be quite similar to the conventional part, i.e., 18,500MJ/part,
especially when considering the uncertainty in LCI data that exist from using numerous sources in the literature.
ConclusionsThe sensitivity analysis concludes that with a 20% reduction in energy use in the conversion of lignin to carbon fiber and
no energy use incurred in lignin production since lignin is a by-product of ethanol and paper production, a 30% reduction
in life cycle energy use could be obtained. A similar level of life cycle energy savings could also be obtained with a higher
part weight reduction potential of 43%.
KeywordsAutomotive lightweighting–Carbon fiber polymer composites–Carbon fibers–Life cycle analysis
... Previous studies have suggested that the environmental impacts of CFRPs could be decreased by transitioning to a bio-based raw material in carbon fiber production (see e.g. Das (2011)) and by recycling the composites and recovering the fibers (see e.g. Meng et al. (2017)). ...
... Carbon fibers, on the other hand, are (usually) produced from polyacrylonitrile (PAN), a fossil-based polymer, where the polymer is first wet spun into a precursor fiber before being turned into a carbon fiber. The transformation to carbon fiber is then done in a series of steps including thermosetting in an oxidizing environment, carbonization in an inert environment, and, finally, treatment to give the fiber surface the right properties (Das, 2011). ...
... The production of lignin-based carbon fibers roughly follows the same production process as described for PAN-based carbon fibers 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 fiber (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 fiber is spun by means of wet spinning, which requires solvents, while the lignin-based precursor fiber 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 fiber 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. ...
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.
... Indeed, CFRP composites are characterized by outstanding mechanical properties such as high stiffness, long life span, non-corrosive and high fatigue resistance [1,2,4]. Lightweight is an additional property of CFRP that can reduce, for instance, the overall weight of a vehicle up to 10% compared to steel and aluminum [5] with a reduction in fuel consumption or an increase in batteries duration for electric vehicles [6], resulting in a lower environmental impact during the use phase [7]. Indeed, CFRP composites are increasingly replacing other materials such as steel [8] and aluminum [9] in a wide range of sectors such as sports equipment, wind energy, aircraft, construction and automotive [4,10,11]. ...
... Concerning the application of LCA to composites, many studies can be found in the literature. LCAs on glass fiber polymers [47,48] and carbon fiber polymers [49][50][51] as well as thermoplastic [52,53] and thermosetting composites [5,52] among different applications, for instance, automotive [8,49,54], aviation [7,55] and construction [48,56,57] sectors. More recent comparative LCAs on CFRP waste management included mechanical, chemical and thermal recycling as alternatives to landfills and incineration [58]. ...
... The use phase of the paddle shifters is directly linked to the use phase of the car, which is mainly related to fuel consumption determined by, for instance, the shape and weight of the car [5]. The latter depends on the materials used. ...
The explosive growth of the global market for Carbon-Fiber-Reinforced Polymers (CFRP) and the lack of a closing loop strategy of composite waste have raised environmental concerns. Circular economy studies, including Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), have investigated composite recycling and new bio-based materials to substitute both carbon fibers and matrices. However, few studies have addressed composite repair. Studies focused on bio-based composites coupled with recycling and repairing are also lacking. Within this framework, the paper aims at presenting opportunities and challenges of the new thermosetting composite developed at the laboratory including the criteria of repairing, recycling, and use of bio-based materials in industrial applications through an ex ante LCA coupled with LCC. Implementing the three criteria mentioned above would reduce the environmental impact from 50% to 86% compared to the baseline scenario with the highest benefits obtained by implementing the only repairing. LCC results indicate that manufacturing and repairing parts built from bio-based CFRP is economically sustainable. However, recycling can only be economically sustainable under a specific condition. Managerial strategies are proposed to mitigate the uncertainties of the recycling business. The findings of this study can provide valuable guidance on supporting decisions for companies making strategic plans.
... Lignin has the potential to be used in pavement construction as a substitute of bitumen up to 25% (Van Vliet et al., 2016), as well as an asphalt binder modifier in both HMA and WMA (Xie et al., 2017). Another practice is the use of lignin as an alternative precursor in carbon fiber reinforced polymers (Das, 2011), which can be used within the upper depth of the pavement for bridge decking (Fang et al., 2017). ...
... The assessment of the environmental impacts of the use of lignin as precursor in CFRPs also showed lower energy demands and climate impacts than current CFRPs (Hermansson et al., 2019). An LCA study of lignin-based carbon fibers by Das (2011) showed that the production of lignin-based carbon fiber requires about 5% less energy than conventional carbon fiber. The results of a study by Batista (2018) showed that since lignin does not increase the release of volatile matter during the production of asphalt mixtures, it does not have any negative impact on human health or the environment. ...
... The high cost of lignin-precursor carbon fibers is also one of the main barriers to the use of lignin in other industries such as lightweight vehicles, which is attributed to the energy-intensive processes of carbon fiber production (Das, 2011). Carbon fibers can also be used in reinforced roads, reducing the maintenance costs to road agencies due to the decreased overlay thickness (Sayida et al., 2020). ...
Large quantities of waste generated in the municipal, commercial and industrial and construction and demolition sectors have caused widespread environmental issues. The replacement of virgin materials with recycled in pavement construction is a possible solution for waste management and achieving sustainability goals in the infrastructure sector. There are, however, questions about environmental and economic impacts of waste-derived materials in road construction that need to be answered. Life cycle assessment and life cycle cost analysis are two approaches to quantify and assess the environmental performance and the costs of decisions regarding the selection of materials for pavement construction. While considerable research has been conducted on pavement materials, the impacts of particular materials such as recycled concrete aggregates, lignin, waste plastic, recycled glass, crushed brick and crumb rubber are not currently well understood. This research presents a synthesis of the state of the art of selected recycled materials in pavement construction and limitations of existing environmental and economic analysis. A major interest towards recycling of materials and necessity of their sustainability analysis is highlighted. The results indicate that the sustainability analysis of selected recycled materials is in its infancy with considerable inconsistencies, hindering the meaningful comparison of results. Furthermore, exclusion of impacts of maintenance, usage and end of life phases from sustainability analysis, impose uncertainty on the long-term viability of these materials. Further research is needed to develop better understanding of these impacts so that more informed decisions could be made by policy makers.
... Moretti [25] conducted an extensive literature review of lignin-related LCAs using the Scopus database (www.scopus.com) on 8 July 2020 and identified 62 papers that presented relevant information. Among these, the sole study on LCA for AP CFs was conducted by Das [26], who compared the primary energy and CO 2 emissions from CFRPs using CFs derived from conventional textile-based PAN with those of CFRPs derived from renewable-based lignin using two manufacturing methods: the programmable powdered preforming process (P4) and sheet molding compound (SMC). The result showed that CFs derived from lignin resulted in 22% fewer GHG emissions than those derived from conventional PAN fibers. ...
... The results of the analysis in this study were compared with similar ones from previous studies. The studies referenced were Das [26], Kawajiri [24], and Murphy [37]. According to these studies, the GHG emissions from CFs from PAN were 31.00, ...
... GHG emissions from flame-resistant CFs were 21.12 kg-CO 2 eq/kg [24]. The GHG emissions from CFs from APs were 24.00 [26], 25.35 from the APs with the classical benzidine method, and 40.46 kg-CO 2 eq/kg from the APs with the coupling method. In the absence of a statement regarding the AP CF production details in Das [26], we assumed that the classical benzidine method was used. ...
Carbon fibers (CFs) are promising lightweight materials to reduce vehicle fuel consumption. However, the most widely used polyacrylonitrile (PAN)-based CF production process consumes a considerable amount of energy. A novel production process for CFs from aromatic polymers (APs) is proposed as an alternative. In this study, the greenhouse gas (GHG) emissions from PAN-based CFs, from APs using the classical benzidine method, and from APs using the coupling method on a cradle-to-gate basis, were analyzed. The results indicate that the AP CFs with the classical benzidine method generated 11% fewer GHG emissions compared with the conventional PAN CFs. Emissions were further reduced by 42% using a large-tow production process. As the classical benzidine method for manufacturing CFs from APs uses a monomer synthesized via benzidine, which is carcinogenic, we examined a different synthetic route using the coupling method for monomer synthesis to avoid the benzidine intermediate. The GHG emissions from the AP CFs manufactured by the coupling method showed a 51% increase compared with PAN-based CFs, indicating a trade-off between GHG emissions and carcinogenicity. However, with proper chemical management, the classical method of CF manufacturing from APs via benzidine showed reduced GHG emissions.
... Beginning in the 1960s, the adoption of carbon fiber reinforced plastics (CFRPs) in structural engineering was primarily motivated by their superior mass-specific mechanical parameters, which can be tailored to the individual application [1]. While CFRPs incorporate a low thermal expansion [2] together with non-magnetic [3] and non-corrosive properties [4], their drawbacks include limited recyclability [5], reparability [6], and often non-destructive quality control [7], as well as a high environmental impact [8]. ...
... self set_roving_area sets the cross-sectional area in mm 2 of a dry roving by filament number or linear density self set_sleeve_points sets the in and out points of a node with given sleeve parameters self set_syntax sets the syntax of the winding object self set_test_parameters sets the parameters of the mechanical test or overrides them self set_tool sets the winding tool based on the tool catalog of the class self set_unit sets the unit of length for the node coordinates self simple_angle returns the included angle at the left node of a list of three nodes self simple_distance returns the Euclidean distance between two nodes cls tabulate_objects returns a table of selected parameters of all winding objects of the class cls tabulate_pyrolysis returns a table of selected parameters of all pyrolysis measurements of the class cls timer_return prints a timer cls timer_start starts a timer cls timer_stop stops a timer self walk sets a path based on the graph and the selected method of traveling static water_density returns the density of water depending on the water temperature self xyz_pos returns the x, y, and z coordinates of a node or position * Method types are indicated as follows: depended on the object (self), depending on the class (cls), and static methods (static). 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20 ...
... Winding syntax of the demonstration component. ,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 2 A, B, D 2× 20, 1, 2, 18, 2, 3, 17, 3, 4,16,4,5,15,5,6,14,6,7,13,7,8,12,8,9,10,11,12,8,12,13,7,13,14,6,14,15,5,15,16,4,16,17,3,17,18,2,18,19,20 ...
Additive manufacturing processes, such as coreless filament winding with fiber composites or laser powder bed fusion with metals, can produce lightweight structures while exhibiting process-specific characteristics. Those features must be accounted for to successfully combine multiple processes and materials. This hybrid approach can merge the different benefits to realize mass savings in load-bearing structures with high mass-specific stiffnesses, strict geometrical tolerances, and machinability. In this study, a digital tool for coreless filament winding was developed to support all project phases by natively capturing the process-specific characteristics. As a demonstration, an aluminum base plate was stiffened by a coreless wound fiber-composite structure, which was attached by additively manufactured metallic winding pins. The geometrical deviations and surface roughness of the pins were investigated to describe the interface. The concept of multi-stage winding was introduced to reduce fiber–fiber interaction. The demonstration example exhibited an increase in mass-specific component stiffness by a factor of 2.5 with only 1/5 of the mass of a state-of-the-art reference. The hybrid design approach holds great potential to increase performance if process-specific features, interfaces, material interaction, and processes interdependencies are aligned during the digitized design phase.
... Production of virgin CFRP: To produce vCFRP, CFs needed to be produced first. Their production was modelled using the data reported elsewhere [5,31]. The inventory of the production process and the unit processes used are presented in Table 2. Table 2. Life cycle inventory of the carbon fibre production process [5,31]. ...
... Their production was modelled using the data reported elsewhere [5,31]. The inventory of the production process and the unit processes used are presented in Table 2. Table 2. Life cycle inventory of the carbon fibre production process [5,31]. The CFRP composite's composition was assumed in this study, corresponding to the results of the thermal recycling experiments. ...
There are forecasts for the exponential increase in the generation of carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) composite wastes containing valuable carbon and glass fibres. The recent adoption of these composites in wind turbines and aeroplanes has increased the amount of end-of-life waste from these applications. By adequately closing the life cycle loop, these enormous volumes of waste can partly satisfy the global demand for their virgin counterparts. Therefore, there is a need to properly dispose these composite wastes, with material recovery being the final target, thanks to the strict EU regulations for promoting recycling and reusing as the highest priorities in waste disposal options. In addition, the hefty taxation has almost brought about an end to landfills. These government regulations towards properly recycling these composite wastes have changed the industries’ attitudes toward sustainable disposal approaches, and life cycle assessment (LCA) plays a vital role in this transition phase. This LCA study uses climate change results and fossil fuel consumptions to study the environmental impacts of a thermal recycling route to recycle and remanufacture CFRP and GFRP wastes into recycled rCFRP and rGFRP composites. Additionally, a comprehensive analysis was performed comparing with the traditional waste management options such as landfill, incineration with energy recovery and feedstock for cement kiln. Overall, the LCA results were favourable for CFRP wastes to be recycled using the thermal recycling route with lower environmental impacts. However, this contradicts GFRP wastes in which using them as feedstock in cement kiln production displayed more reduced environmental impacts than those thermally recycled to substitute virgin composite production.
... fossil, nuclear, solar) used by the processes included in the system boundaries. Since the CFRP production technologies are characterized by high energy consumptions, the CED is a meaningful indicator for these processes; for this reason, it was widely used in previous LCA studies [6,45,46]. • The Global Warming Potential (GWP, expressed in kg CO 2 eq) is used to quantify the greenhouse gases (GHG) emissions in the atmosphere and their effects on global warming and climate change. The methodology described by the Intergovernmental Panel on Climate Change (IPCC) was followed. ...
... The methodology described by the Intergovernmental Panel on Climate Change (IPCC) was followed. It considers the heat absorbed by any greenhouse gas as a multiple of the heat that would be absorbed by the same mass of carbon dioxide (CO 2 ) and assess their effects over the years [6,25,42,[45][46][47][48][49]. • The ReCiPe method, developed in 2008, provides a comprehensive view of the effect of a product or a process on the environment, considering 18 midpoint impact categories that focus on specific environmental problems (e.g. ...
In the present paper, the environmental impact of an innovative technology, based on a zero-waste approach, for reclaiming carbon fiber prepreg scraps is assessed. The innovative process, proposed within the European project CIRCE, aims at reclaiming scraps produced during the cutting operation of virgin prepreg, avoiding the waste materials landfilling or incineration. The prepreg scraps were transformed into a ready-to-use raw secondary material by using two specifically developed automated systems for cutting and peeling of the scraps. By exploiting the prepared scraps in a compression molding process, recycled composite parts were produced. The evaluation of the environmental impact was carried out by means of the Life Cycle Assessment (LCA) approach, using the different impact assessment methodologies based on the Cumulative Energy Demand, Global Warming Potential and ReCiPe methods. Furthermore, tensile tests were performed at room temperature to investigate the mechanical properties of the recovered scraps products. In order to evaluate the environmental benefits of the innovative compression molding production with recovered prepreg scraps, the LCA analysis was also performed on two different traditional virgin production scenarios, i.e. the compression molding production with virgin prepreg and the autoclave processing with virgin prepregs, both used for the production of CFRP parts. The results show that the reclaim process leads to a strong reduction of the environmental impacts with respect to traditional composite production processes, demonstrating that such process can represent a valid alternative for a more sustainable manufacturing of composite products.
... They capture CO 2 during growth, and their harvesting does not use large amounts of fuel energy. Their complete production requires, on average, 5-10 times less nonrenewable energy than glass fibres [18,19] and 30-70 times less than carbon fibres [20]. Other advantages of natural fibres are lower pollutant and greenhouse emissions, more significant energy recovery, and end-of-life biodegradability of its components [19]. ...
... For applications of CFW in architecture, especially for structures exposed to sunlight, the use of thermoset matrices as epoxy resin is more desirable due to its heat resistance and higher mechanical properties. Table 1 also compares data for oil-based epoxy and bio-based epoxy resins, as well as values for most representative LCA indexes related to the production of the material [18,20,21,32]. A complete LCA assesses the environmental aspects and potential impacts of the full product's life cycle, from the extraction of the raw material, through the material production and manufacturing, to the use and end-of-life treatment [33]. ...
... They capture CO 2 during growth, and their harvesting does not use large amounts of fuel energy. Their complete production requires, on average, 5-10 times less nonrenewable energy than glass fibres [18,19] and 30-70 times less than carbon fibres [20]. Other advantages of natural fibres are lower pollutant and greenhouse emissions, more significant energy recovery, and end-of-life biodegradability of its components [19]. ...
... For applications of CFW in architecture, especially for structures exposed to sunlight, the use of thermoset matrices as epoxy resin is more desirable due to its heat resistance and higher mechanical properties. Table 1 also compares data for oil-based epoxy and bio-based epoxy resins, as well as values for most representative LCA indexes related to the production of the material [18,20,21,32]. A complete LCA assesses the environmental aspects and potential impacts of the full product's life cycle, from the extraction of the raw material, through the material production and manufacturing, to the use and end-of-life treatment [33]. ...
Coreless filament winding (CFW) is a novel fabrication technique that utilises fibre-polymer composite materials to efficiently produce filament wound structures in architecture while reducing manufacturing waste. Previous projects have been successfully built with glass and carbon fibre, proving their potential for lightweight construction systems. However, in order to move towards more sustainable architecture, it is crucial to consider replacing carbon fibre’s high environmental impact with other material systems, such as natural fibre. This paper evaluates several fibres, resin systems, and their required CFW fabrication adjustments towards designing and fabricating a bio-composite structure: the LivMatS Pavilion. The methods integrate structural design loops with material evaluation and characterisation, including small-scale and large-scale structural testing at progressive stages. The results demonstrate the interactive decision-making process that combines material characterisation with structural simulation feedback, leveraged to evaluate and optimise the structural design. The built pavilion is proof of the first successful coreless filament wound sustainable natural fibres design, and the developed methods and findings open up further research directions for future applications.
... The study is cradle-to-grave which means it includes the raw material extraction, composite and structural batteries production, the use phase as well as the end-of-life treatment. It was assumed that the vehicle was driven for 200 000 km before being discarded, which is in line with other studies for composite vehicles, but with internal combustion engines (see for example Duflou et al. [6] and Das [7]). The production, use, and disposal of the composites is assumed to take place in Germany, using German or European specific data as far as possible. ...
... It is not unlikely that the energy consumption in the SB manufacturing process will approach the RTM energy consumption as technology is further developed. In addition to this, carbon fibre production can be made more energy efficient, which would decrease the impact of both CFRPs and SBs, for example by the use of bio-based raw materials (see for example: Das [7], Janssen et al. [26] and Hermansson [27]), and the use of microwave technology in carbon fibre production (see for example Lam et al. [28]). b) Figure 2b) shows the crustal scarcity impact for the different cases. ...
One way to reduce the environmental impact of an electric vehicle is to reduce the vehicle's mass. This can be done by substitution of conventional materials such as steel, aluminium, and plastics with carbon fibre composites, or possibly even with structural battery composite materials. In the latter case, another consequence is that the size of the vehicle battery is reduced as the structural battery composite not only provides structural integrity, but also stores energy. This study assesses the change in life cycle environmental impacts related to transitioning from a conventional battery electric vehicle to a vehicle with components made from either carbon fibre composites or structural battery composites, with the aim of identifying environmental challenges and opportunities for cars with a high share of composite materials. Results show that a transition to carbon fibre composites and structural battery composite materials today would (in most cases) increase the total environmental impact due to the energy intensive materials production processes. The two major contributors to the environmental impacts for the structural battery composite materials are energy intensive structural battery material manufacturing process and carbon fibre production process, both of which can be expected to decrease their energy consumption as the technology maturity level increases and other production and manufacturing processes are developed. For future assessments, more effort needs to be put on collecting primary data for large-scale structural battery composites production and on assessing different technology development routes.
... These four stages include: goal and scope definition, life cycle inventory analysis (LCI), life cycle impact assessment (LCIA), and interpretation. Several researchers have used LCA to analyze potential environmental impacts of various products and systems [11][12][13]. ...
... These studies indicated various hot spots during the life cycle of a product that contribute most towards the environmental degradation. Products including wind turbines [11] and polymer composites [12] have been studied using LCA. LCA of electronics boards used in different products has also been carried out [13]. ...
External corrosion is one of the major defects for oil and gas pipes. Multiple repair techniques are used for repairing such pipes, which have different environmental effects. In this study, the life cycle assessment (LCA) approach has been used to investigate the environmental impacts of four commonly used repair techniques. The techniques are fillet welded patch (FWP), weld buildup (WB), mechanical clamp (MC), and non-metallic composite overwrap (NCO). The repair processes based on guidelines from repair standards are carried out on a defected pipe specimen and experimental data required for LCA are collected. The paper conducts a cradle-to-gate LCA study using SimaPro software. Six environmental impact categories are used for the comparison of repair processes. The results for a repair life of ten years indicate that non-metallic composite overwrap has the highest whereas the fillet welded patch has the lowest environmental impacts.
... Carbon fiber (CF) has emerged as an important material in vehicle lightweighting to improve fuel economy through its usage as reinforcement in plastics in automotive components (Das 2011;Ghosh et al. 2021;Pradeep et al. 2017;Taub et al. 2019). CF is also used in the outer lining of hydrogen tanks in fuel-cell vehicles (FCVs) (Moradi and Groth 2019), which are an alternative to conventional internal combustion engine vehicles (ICEVs) with zero tailpipe emissions. ...
... CF is also used in the outer lining of hydrogen tanks in fuel-cell vehicles (FCVs) (Moradi and Groth 2019), which are an alternative to conventional internal combustion engine vehicles (ICEVs) with zero tailpipe emissions. Yet, the lightweighting capability of CF as well as its suitability for use in alternative energy-powered vehicles are accompanied by its high costs and energy intensity of CF production (Das 2011;Ghosh et al. 2021;Nunna et al. 2019). This makes it critical to quantify the trade-off between the weight reduction via use of CF and the increase in energy use for vehicle production, or even the trade-off between the decrease in greenhouse gas (GHG) emissions and the rise in GHG emissions during production for FCVs over ICEVs. ...
This memo documents updates in the GREET® 2021 model for the carbon fiber pathway and the weight-ratio of constituents (resin and fiber) in carbon fiber-reinforced plastic.
Link: https://greet.es.anl.gov/publication-carbon_fiber_2021_update
... Carbon fiber-reinforced polymer composites (CFRP) are one of the most popular types of composite [1][2][3][4] in the aerospace [5,6], automotive [7,8] and recreational sports goods [9,10] industries due to their high strength and stiffness-toweight ratios [11][12][13]. However, the high volume percentage of fibers required for mechanical performance and the high price of carbon fiber [14][15][16] limit wider application of CFRP. ...
Carbon nanotubes (CNTs) orient in a polymer matrix under electric field due to their highly anisotropic electric polarizability. Under direct current (DC) electric field, CNT also migrates toward electrodes resulting in a non-uniform CNT concentration which can affect the properties gained from CNT alignment. In this study, DC electric field was applied across a CNT/epoxy mixture and the kinetics of CNT migration were studied in real time as a function of electric field strength, CNT concentration and length distribution. The rate constant k of CNT migration was found to be linearly proportional to the electric field strength, while varying the CNT concentration and length distribution exhibited a minimal effect on the migration velocity. Combined with our previous study of the temperature dependence of CNT migration, the relationship between the rate constant k of CNT migration and electric field strength, CNT concentration and length distribution was established. The resulting relationship can be used to manipulate the spatial distribution of CNT to selectively enhance the mechanical, thermal and electrical properties of CNT/polymer composites.
... Deploying the cutoff approach under a fleet-based dynamic LCI analysis, Du et al. [30] assessed the GHG and energy savings of introducing aluminum-intensive vehicles to the current Chinese vehicle fleet. In the presence of the end-of-life recycling method, Ribeiro et al. [31], Bertrum et al. [32], Puri et al. [33], Das [34], Baroth et al. [35], and Dhingra and Das [36], conducted conventional product-based LCI analyses to learn the life-cycle GHG and energy benefits bound to high-strength steel and aluminum fenders, aluminum body parts, aluminum and fiber door skins, steel, carbon-fiber-reinforced plastic -based floor panels, plastic fenders, and aluminum-and magnesium-substituted automotive engines, respectively. Similar natured studies, such as Mayyas et al. [37] and Dubreuil et al. [38], are also evident. ...
Light weighting by material substitution is a key to reducing GHG emissions during vehicle operation. The GHG benefits are a salient factor in selecting lightweight materials for vehicles. Although the literature has performed lightweight material selections using GHG benefits under product- and fleet-based life-cycle inventory (LCI) analyses, recycling effects have therein been accounted for by arbitrarily selecting allocation methods for recycling, as the consensus on their selection is absent. Furthermore, studies have mistreated the temporal variations of the LCI parameters (the dynamic inventory (DI)), though that could be an important factor affecting the overall LCI results when allocation methods for recycling are in place. Therefore, to investigate their influence on greenhouse gas (GHG) benefit evaluations, an LCI case study was conducted, centered on aluminum- and magnesium-substituted internal combustion engine vehicles (ICEVs) at the product- and fleet- levels. “CO2 savings” and the “CO2 payback time”, as well as four allocation methods for recycling, were considered to represent the GHG benefits and address the recycling effects, respectively. The dynamic inventory was based on the world average electricity grid mix change. The results indicate that changing the conditions of the DI and the allocation methods for recycling could alter the better performing material under fleet-based analyses. Therefore, we ascertained that the choice of the allocation method for recycling and conducting fleet-scale dynamic LCI analyses in the presence of the DI is pivotal for material selections.
... Although the length of the flakes produced here is much shorter than those in carbon fiber, it is easy to imagine that directional precipitation and crystal growth can be induced if the ribbons were to be pulled through a hot zone rather than homogeneously annealed, and this should lead to very long graphite crystals. Assuming these may be spun into fiber with a suitable binder (we have not produced enough material to perform this test), this approach may be a more benign method to produce carbon fiber precursors from a life-cycle approach, as it is well-known that carbon fiber produced from polymeric precursors is an energy and resource intensive process, leading to significant emissions during the oxidation and graphitization cycles at high temperature [43]. ...
We report the structural transformations of carbon via the melt spinning and subsequent annealing of nickel-carbon alloys. We attained metastable solid solubility of carbon in nickel ribbon by achieving a rapid solidification rate of up to 1.6 x 10⁶ K/s. Excess carbon atoms were found to be dissolved in the nickel lattice causing up to 1.4% strain for an alloy spun at 70 m/s tangential wheel speeds. High temperature heat treatments led to precipitation of carbon from the nickel lattice on the ribbon free surfaces but also led to growth of spherical precipitates within the nickel matrix, an effect consistent with bulk diffusion-driven Ostwald ripening. Carbon was excavated from the ribbons via chemical dissolution of the metal and characterized by electron microscopy and Raman spectroscopy. We found that the microstructure of carbon precipitated from the rapidly quenched ribbon could be tuned by varying the carbon content from 4 – 12 at. % in the precursor and annealing the ribbon at temperatures that ranged from 400 – 1200 °C. Via the step-wise variation of these two parameters, we sequentially transformed amorphous carbon nanospheres with a high BET surface area of 203.4 m²/g into thick, highly crystalline flakes of graphite that conformed to the shape of the as-spun ribbon.
... Today carbon fibre reinforced polymers (CFRP) are extensively used. In automobiles, a 30% reduction in life cycle energy use can be achieved by replacing conventional materials with CFRP (Das, 2011). During the past decade, the demand for carbon fibre (CF) has undergone a rapid increase with an average annual growth rate of over 15% p.a. ...
The increasingly strict legislation on plastic recycling and the public concerns about environmental protection have driven the waste plastics recycling industry and the development of recycled plastics applications. However, recycled plastics are rarely used in high-value-added applications, especially in the automobile industry. This thesis aimed to investigate the feasibility of utilising recycled plastics for auto parts manufacturing. It started with the background study focused on the use of plastics in automobiles and the status of waste plastic recycling in China. Recycled polypropylene (RPP) was selected as the focused material because it is widely used for the manufacturing of automobiles parts. A literature review of recycled plastics was conducted to understand the degradation mechanism and reinforcing techniques in detail. The experimental study consists of four sections: 1) Development and characterisation of the RPP/Talc composites for the manufacturing of the armrest box. The prepared formula processed the industrial trial, the products meet all the mechanical requirements of the armrest box, and it can save 35.2% of material cost. 2) Preparation of RPP-based blends for automobile bumper. With the addition of 20 wt% of maleic anhydride grafted linear low-density polyethylene (LLDPE-g-MA), the notched impact strength of the RPP composites improved by 252.6%. And 10 wt% LLDPE-g-MA filled RPP3 meet the mechanical requirements for the middle-end bumper. 3) Process development for the use of recycled short milled carbon fibre (rSMCF) as a filler and investigation of its effects on the mechanical properties of the composite. By adding 5 wt% rSMCF, the tensile modulus and flexural modulus of RPP composites increased by 52.3% and 47.3%, respectively. And the coupling agent maleic anhydride grafted polypropylene (MAPP) significantly improved the interfacial adhesion between rSMCF and PP matrix. At 5 wt% MAPP loading, The tensile strength and flexural strength of 5 wt% RSMCF filled PP composites was increased from 21.8 MPa to 24.3 MPa and 27.2 MPa to 31.7 MPa, respectively. This study shows that only a small amount of rSMCF addition will contribute to significant improvement of polypropylene (PP) based composites in tensile and flexural properties. 4) Evaluating the effects of hollow glass bead (HGB) on weight reduction, mechanical behaviours and flame retardancy. The effects of MAPP on compatilising RPP and fillers were analysed, the interfacial effects were studied by the microscale observation. By addition 10 wt% of HGB, the total weight of VPP and RPP composites have a reduction of around 4%. The reduction of impact properties is the major drawback of HGB. By adding 10 wt% of HGB in RPP3 and RPP4, the un-notched impact strength reduced by 54.1% and 48.5%. The processed cone calorimeter test shows by adding 10 wt% HGB to VPP, the heat release rate decrease from 766.6 kW/m2 to 536.6 kW/m2 . The mechanism of the flame retardancy of HGB was further analysed by scanning electron microscopy, during the burning HGB can form an effective protection layer floating on the melted plastics to suppress the flame and thus improve the flame retardancy of PP composites. This study found that it is possible to partially replace virgin polypropylene (VPP) with RPP in some specific automobile applications. The novelty of this research is the utilisation of well-developed techniques (filler addition, polymer blending) to develop recycled composite to meet the requirement from manufacturers and evaluate its performance in real automobile parts. It presented a crucial step from the lab-scale study to the large-scale industrial use of recycled plastics in the automobile industry. This study developed a process for manufacturing rSMCF filled PP composites. By only using a small amount <5 wt%) of rSMCF, the mechanical properties of PP composites significantly improved. The use of recycled carbon fibre (rCF) in recycled plastics provide a cost-effective way for both resource-saving and properties reinforcement. In order to reduce the environmental impact on the automobile industry, HGB was introduced as a lightweight material into the PP matrix for weight reduction. The mechanical and flammability results of HGB filled PP composites were investigated and discussed. The developed process for utilizing rCF and HGBs showed the potential of a more sustainable and lower environmental impact pathway for the automobile industry.
... An evaluation of a recycling process' environmental appropriateness must evaluate all of the process' possible environmental effects. The use of life cycle assessment is well established in many sectors, and it is becoming increasingly popular in the composites area, where it has been used to investigate the environmental implications of replacing more frequently used material types with composites in transportation applications [204]. A number of fascinating overviews of the challenges and new methods have been presented, focusing primarily on the recycling of carbon fiber composites for structural purposes [205]. ...
To meet the increasing energy demand, renewable energy is considered the best option. Its patronage is being encouraged by both the research and industrial community. The main driving force for most renewable systems is solar energy. It is abundant and pollutant free compared to fossil products. Wind energy is also considered an abundant medium of energy generation and often goes hand in hand with solar energy. The last few decades have seen a sudden surge in wind energy compared to solar energy due to most wind energy systems being cost effective compared to solar energy. Wind turbines are often categorised as large or small depending on their application and energy generation output. Sustainable materials for construction of different parts of wind turbines are being encouraged to lower the cost of the system. The turbine blades and generators perform crucial roles in the overall operation of the turbines; hence, their material composition is very critical. Today, most turbine blades are made up of natural fiber-reinforced polymer (NFRP) as well as glass fiber-reinforced polymer (GFRP). Others are also made from wood and some metallic materials. Each of the materials introduced has specific characteristics that affect the system’s efficiency. This investigation explores the influence of these materials on turbine efficiency. Observations have shown that composites reinforced with nanomaterials have excellent mechanical characteristics. Carbon nanotubes have unique characteristics that may make them valuable in wind turbine blades in the future. It is possible to strengthen carbon nanotubes with various kinds of resins to get a variety of different characteristics. Similarly, the end-of-life treatment methods for composite materials is also presented.
... Globular protrusions are usually found in the pit, which are known as tylosis (Madueke et al., 2021). Under stress or during invasion of pathogens, the protoplast of the adjacent parenchymatous cells is overgrown to generated a new wall material, i.e., the Table 1 Tensile properties and embodied carbon footprint of conventional fibre as reinforcement in cementitious matrix (Wang et al., 2021;Zoghi, 2013;Richaud et al., 2018;Jones and Hammond;Das, 2011;Grasselly, Hamm, Quaranta, Vitrou;Dittenber and GangaRao, 2012;Thienel, 2020 tylosis (AGRIOS, 2005). The tylosis usually consists of cellulose, hemicellulose, pectin, suberin as well as lignin (Micco et al., 2016). ...
This paper provides a comprehensive review on the research of coir fibre and coir fibre reinforced cementitious composite (CFRC) in the past 20 years. In the first part, the extraction process, morphology, density, chemical composition, and tensile performance of coir fibres are discussed. Then, the pull-out performance, physical properties (i.e., density, thermal and acoustic insulation), short- and long-term properties (i.e., compressive, flexural, impact, and dynamic performance) of CFRC are reviewed. Existing modification methods (i.e., cementitious matrix and fibre surface modifications) to improve the bond and mechanical behaviour of CFRC and the practical application of CFRC in construction are presented. Future perspectives of CFRC studies are highlighted, including the validation of existing models (i.e., for the prediction of coir tensile strength as well as bond strength and total energy of CFRC), further investigations on long-term, seismic, fire performance of CFRC, and the use of coir fibre in geopolymer and coconut shell aggregate concrete towards practical application.
... While input quantities and associated carbon factors were available for carbon fibre production, no specific data on process emissions were available. These process emissions were estimated based on previous work by Das [15]. Based on the gross calorific value of natural gas (most bills are reported in terms of gross calorific value [19]). ...
This paper examines a large structural component and its supply chain. The component is representative of that used in the production of civil transport aircraft and is manufactured from carbon fibre epoxy resin prepreg, using traditional hand layup and autoclave cure. Life cycle assessment (LCA) is used to predict the component's production carbon emissions. The results determine the distribution of carbon emissions within the supply chain, identifying the dominant production processes as carbon fibre manufacture and composite part manufacture. The elevated temperature processes of material and part creation, and the associated electricity usage, have a significant impact on the overall production emissions footprint. The paper also demonstrates the calculation of emissions footprint sensitivity to the geographic location and associated energy sources of the supply chain. The results verify that the proposed methodology is capable of quantitatively linking component and supply chain specifics to manufacturing processes and thus identifying the design drivers for carbon emissions in the manufacturing life of the component.
... Established for decades, reinforcing materials made of carbon-fibre-reinforced plastics have satisfying mechanical properties. However, carbon fibres have high amounts of embodied energy (total energy intensity of carbon fibre is estimated to be 284 MJ/kg [7][8][9]) and are generally expensive. On the other hand, basalt fibres are sustainable materials with comparatively lower amount of embodied energy (total energy intensity of basalt fibre of 18 MJ/kg [10][11][12]. ...
The level of energy consumption in renovation activities of buildings has huge advantages over the demolition of old buildings and the construction of new structures. Such renovation activities are usually associated with the simultaneous strengthening of their elements, such as externally bonded carbon fibre reinforced polymer (CFRP) lamellas or sheets on vertical and horizontal surfaces as structural reinforcements. This means the process of refurbishing a building, as well as the raw materials themselves have a significant impact on CO2 emissions and energy consumption. This research paper demonstrates possibilities of replacing state of the art, highly energy-intensive CFRP lamellas with basalt fibre reinforced plastics as energy-efficient structural reinforcements for building constructions. The mechanical and thermal properties of basalt fibre reinforced polymer (BFRP) composites with variable matrix formulations are investigated. The article considers macro- and microstructures of innovative BFRP. The investigations focus on fibre–matrix interactions with different sizing formulations and their effect on the tensile strength, strain as well as modulus of elasticity.
... 1,6 Especially the development of CFRPs for constructive solutions toward reducing weights of aircraft or automotive vehicles could reduce the overall CO 2 emissions by approximately 10−20% compared to conventional metallic construction systems when considering their service life. 7,8 Although a variety of applications have been reported, CFs are currently only used for small niche products because of their high price, due to the high manufacturing and processing costs. Besides this, the price is directly influenced by the cost of the precursor material. ...
... [19][20][21] Also, polymer composites have lightweight that can reduce vehicles' fuel consumption and CO 2 emission in the atmosphere. 22 Using FRAM technology, complex parts can be produced easier compared to the traditional methods. 23 Despite all the advantages of AM technology, lack of mechanical performance is considered as the main weakness of the AM polymer parts. ...
Mechanical properties of fiber reinforced additive manufacturing (FRAM) parts are affected by the fiber size and orientation. Oriented fiber composite is most likely to produce better properties. The objective of this research is to perform a comparative analysis of the mechanical properties of short and continuous fiber reinforced nylon 6 produced with fused filament fabrication (FFF) technology. In this study, it was observed that tensile, compression and flexural properties are significantly affected by the change in the fiber length and orientation. Scanning electron microscopy (SEM) was performed after mechanical testing to observe the influence of fiber on the final properties. From the testing, it was observed that continuous-FRAM (C-FRAM) parts show better properties in tensile loading and short-FRAM (S-FRAM) in bending. S-FRAM parts show better improvement in flexural and compression properties as compared to CFRAM parts. Morphological analysis of tested 3D-printed parts concluded that the fiber-pull out and fiber breakage are the main failure mechanisms.
... In another LCA study about glass fibres, it was reported that during production of glass fibres the energy used to melt the glass accounted for majority of carbon emissions associated with glass fibre production [127]. For this reason, replacing glass fibres with natural fibres has been investigated by various researchers as one of the most promising ways of reducing the environmental impacts of composites materials [126,[128][129][130][131] Overall, it is reported that using plant-based fibres in composites improves the sustainability of composites [132] and several types of bio fibres can be used for reinforcing composite materials. Oliver-Ortegar et al. [133] reported a study in which authors have used cellulose as a reinforcing nanofibre network in a polymer matrix and have reported that the resulting composite showed excellent mechanical properties. ...
Epoxy clay nanocomposites have been proven to have improved mechanical, thermal and physical properties over pristine matrix. Thus, the fields of application of epoxy-clay nanocompo-sites along with their hybrid glass/carbon fibre reinforced composites have grown tremendously during the last few decades. The present review paper covers the research work performed on epoxy clay nanocomposites. It includes the influence of the processing techniques and parameters on the morphology of the nanocomposite, the methods of characterization and the effects of adding nanoclay on the mechanical and physical properties of composite. The improvements in the liquid barrier properties brought about by the addition of nanoclay platelets to epoxy resin are discussed. The variation of physical and mechanical properties with nanoclay type and content are reviewed along with the effects of moisture uptake on these properties. The advances in the development, characterization and applications of hybrid glass fibre reinforced epoxy-clay nanocomposites are discussed. Findings of the research work on the influence of nanoclay addition and exposure to water laden atmospheres on the behaviour of the hybrid glass fibre epoxy-nanoclay composites are presented. Finally, the potential health and environmental issues related to nanomaterials and their hybrid composites are reviewed.
... The authors declare no conflict of interest. 130 [61] 183-286 [21,92] 198-595 [93] 338.97 [74] 390-420 [72] 460 [94] ...
Coreless filament winding is an emerging fabrication technology in the field of building construction with the potential to significantly decrease construction material consumption, while being fully automatable. Therefore, this technology could offer a solution to the increasing worldwide demand for building floor space in the next decades by optimizing and reducing the material usage. Current research focuses mainly on the design and engineering aspects while using carbon and glass fibers with epoxy resin; however, in order to move towards more sustainable structures, other fiber and resin material systems should also be assessed. This study integrates a selection of potential alternative fibers into the coreless filament winding process by adapting the fabrication equipment and process. A bio-based epoxy resin was introduced and compared to a conventional petroleum-based one. Generic coreless wound components were created for evaluating the fabrication suitability of selected alternative fibers. Four-point bending tests were performed for assessing the structural performance in relation to the sustainability of twelve alternative fibers and two resins. In this study, embodied energy and global warming potential from the literature were used as life-cycle assessment indexes to compare the material systems. Among the investigated fibers, flax showed the highest potential while bio-based resins are advisable at low fiber volume ratios.
... To produce the carbon fibres, PAN (polyacrylonitrile fibres) is normally used as precursor. As carbon fibers are not available in the Ecoinvent database, PAN is used (available in the database) with the addition of the electricity required for the production of the fibers (Das, 2011). Since they were manufactured in Germany, the transport distance was considered ( Table 1). ...
The case study presented in this paper is a follow up of a topic already examined in previous studies relating the life cycle assessment (LCA) of a chemical treatment process used to recycle a specific type of carbon fiber (CF) reinforced thermoset composite. In the present study the LCA is coupled with the life cycle cost (LCC) analysis for the economic assessment. Furthermore, the research sought to specify the best available technology for the reuse of the materials recovered through the chemical recycling process. The new LCA results are more reliable and more current than the scenario presented in the previous LCA studies. In the previous scenario the possibility to recover long carbon fibers “ready to use” was considered. This scenario, even if under investigation by the recycling company, is still not possible for technological limitations as the fibers recovered after the chemical process require further treatments before being used in thermoset composite. Consequently, a more feasible technology was investigated and, according to our laboratory research results, one practical way to recycle the CF-thermoset composites is to shred them before the chemical treatment in order to recover shredded CFs and epoxy thermoplastic from cleavable thermosets. These materials can be easily compounded together to manufacture a CF-thermoplastic composite through injection moulding as we demonstrated herein through some laboratory experiments. The LCA and LCC were accounted for the recycling process via solvolysis up to the recovery phase of the epoxy-thermoplastic resin and the short carbon fibers. The paper presents laboratory test results of the remanufacture of the two reclaimed materials for the production of a thermoplastic CF-composite.
... 2.1 zu entnehmen, jeder der Prozessmodule des LCAs bei der Interpretation beitragen. In der anfänglichen Definition ist das Abstecken der Systemgrenze maßgebend für 9 2 Stand der Technik die Bewertung. Weiterführend dient die Sachbilanz als sehr transparenter Einblick in die Elementarflüsse des Produktsystems, welche mittels der Wirkungsabschätzung einzeln in das Verhältnis der ökologischen Auswirkung des gesamten Systems gesetzt werden kann. ...
Zur Verbesserung der Ökobilanz der Betriebsphase von Flugzeugen geht seit Jahren der Trend dazu über, immer größere Anteile der Strukturmasse aus karbonfaserverstärkten Kunststoffen (CFK) zu fertigen. Dabei stehen dem technischen Nutzen des CFKs relativ hohe Kosten und Umweltauswirkungen insbesondere in der Produktionsphase entgegen. Eine Entwicklung eines kombinierten Bewertungsmodells für ökonomische und ökologische Aspekte der CFK-Herstellung ist deswegen notwendig, um Entscheidungsträger:innen mit Informationen zu versorgen, die bei der Realisierung nachhaltiger Entwicklungsprozesse die Entscheidungen unterstützen. Das Eco-Efficiency-Assessment-Model (EEAM) stellt ein solches Modell für den Fertigungsprozess von Faserverbundbauteilen dar. Darauf aufbauend wird in dieser Arbeit der Montageprozess betrachtet. Es wird ein generisches Modell zur Bewertung der Ökoeffizienz verschiedener Montagetechnologien erstellt. Die Bewertung wird mithilfe der Cradle-To-Gate Ökobilanzierung durchgeführt und beinhaltet den ökonomischen Indikator der Direktkosten (DC) und die ökologischen Indikatoren des Kumulierten Energiebedarfs (CED) sowie 18 Midpoint-Indikatoren der ReCiPe-Methode. Angewandt wurde dieses Modell in einer Fallstudie zur Bewertung der Fertigung und Montage von Probekörpern eines Holmsegments für einen Flügel eines unbemannten Ultraleicht-Stratosphärenflugzeugs. Die Fertigung erfolgte über das Wickeln von PrepregMaterial und anschließendem Aushärten in einem Autoklav. Die Montage wurde mittels Klebung realisiert. Die Prozesse fanden unter Laborbedingung mit niedrigem Produktionsvolumen statt.
In the present study, a holistic End-of-Life (EoL) Index is introduced to serve as a decision support tool for choosing the optimal recycling process among a number of alternative recycling techniques of CFRP waste. For the choice of the optimal recycling process, quality of the recycled fibers as well as cost and environmental impact of the recycling methods under consideration, are accounted for. Quality is interpreted as the reusability potential of the recycled fibers; that is quantified through the equivalent volume fraction of recycled fibers that balances the mechanical properties of a composite composed of a certain volume fraction of virgin fibers. The proposed Index is offering an estimated balanced score, quantifying a trade-off between the reusability potential of the recycled fibers as well as the cost and the environmental impact of the recycling methods considered.
Maintenance and repair are necessary to maintain the car's functions throughout its life. As the car ages, maintenance and repairs are becoming more common and consume more and more resources and energy. In this study, the Life Cycle Assessment (LCA) methodology was used to a case study of different maintenance scenarios of internal combustion engine passenger car. The LCA examination is focused on thorough maintenance inventory of a popular compact car, Ford Focus II. The examination considered different maintenance scenarios. The first followed Ford Maintenance Schedule. The other was made to include car breakdown cases, as reported by car users. Both scenarios of maintenance and repair were analyzed using data from 40 vehicles regularly using Ford authorized service center. Material inventories in other stages of the car life cycle were modeled with Ecoinvent data. The environmental impact of maintenance and repair was another focus of the study. The inventories were combined to model different car maintenance scenarios. Each vehicle scenario was further modeled in ICE diesel and petrol versions to compare their maintenance and repair options and to compare data with earlier studies. Another model described a diesel engine version with earlier oil exchange, which often ocuurs in cars that are used mainly in urban environment.
The main conclusion is that a new level of thoroughness of inventory data provides by 58% higher effect of car maintenance and repair in a petrol car and by 95% higher in a diesel compared to earlier research. For the scenario with shortened oil exchange interval the effect is twice as great.
View Video Presentation: https://doi.org/10.2514/6.2021-2410.vid While batteries have substantially lower energy per unit mass than hydrocarbon fuels, aircraft with electrified propulsion systems have the potential to deliver energy savings compared to conventional aircraft, and may produce less carbon dioxide (CO2) emissions during flight. However, whether electrified aircraft are ultimately more or less environmentally friendly depends on their entire life-cycle footprint. This work models and compares the well-to-wake life-cycle equivalent CO2 (CO2e) emissions, including manufacturing, service life emissions, and end of life, of both fully electric and conventionally powered aircraft for a commuter thin haul mission. Results show that with intermediate 2035 electrical component technology, the all-electric aircraft is heavier and consumes roughly 8% more energy in flight than the 2035 advanced conventional turboprop. In spite of this, when batteries are recharged on a projected US 2035 grid with 31.5% renewable sources, this all-electric commuter produces about 80% less CO2e over its entire life-cycle. Thus the total life-cycle emissions of all-electric aircraft are substantially lower than those of conventional aircraft. With further improvements in electrical technology and a 50% renewable electricity production, all-electric commuter aircraft produce 91% less CO2e over their lifetime.
A surface‐modified carbon‐fiber reinforced epoxy (CF/E) via a unique isophorone diisocyanate amine (IDA) reaction produces a new interfacial epoxy‐polyurea “matrix” (IEPM) that elicits excellent mechanical energy transferability in brittle CF/E. The chemical bonding property in the IEPM molecule is produced via moieties of an epoxy mixture and N‐H‐concentrated urea molecules, where IDA thermodynamics are controlled via a curing parameter, tc (in hours). Nano‐scale properties of the IDA reaction, confirmed via fourier‐transform infrared spectroscopy and chemical mapping of molecules comprising the IEPM structure, are linked to bulk mechanical energy transferability, specifically loss modulus, E″(ω), and post‐elastic energy absorption. Using dynamic mechanical analysis (DMA) of six test specimens and a Generalized Maxwell Model – verified via Prony Series calibration of the storage modulus to DMA data to compute relaxation parameters – the ultrathin IEPM is isolated, and E″(ω) is computed as a function of tc. IEPM that is produced via tc = 0 exhibited two, six, and ten times greater loss modulus than IEPM produced via 0.5 ≤ tc ≤ 2; tc = 3.5; and tc = 24 (baseline design utilizes cured CF/E). Finally, IDA surface‐modification of CF/E improved energy absorption capacity (post‐elasticity) between 250% (tc = 0.5) and 300% (tc = 0). The creation of a new scalable molecule follows epoxy surface modification via isophorone diisocyanate amine reaction. The molecule includes high‐enthalpic isocyanate‐rich urea‐bonds whose thermodynamics and molecular vibrational properties are controlled via curing kinetics. Nano‐scale material changes are linked to designable bulk properties, including loss modulus and post‐elasticity, and are imparted to large‐scale composite structures subject to extreme multi‐hazards forces.
The composite ballistic solution is a growing domain due to ever-increasing threats for security personnel. These composite solutions focus on enhanced protection level with reduced weight, resulting in less hindrance to the mobility of wearer. But the environmental aspect of these composite materials is usually neglected. This chapter focuses on the life-cycle assessment (LCA) of a ballistic vest, assessing its environmental loads, and identifying and quantifying energy and materials used and wastes released to the environment. The LCA shows all the interconnected processes of a product life cycle, that is, raw material, manufacturing, application, and end of life. It spans over the cradle-to-grave life cycle of the body armor, covering all the steps involved.
Carbon fibre manufacturing is characterized by a high energy demand due to long processing times and energy intensive thermal processes. Since energy flow related information about the carbon fibre production is rare, lacks in detail and ranges widely, the goal of this paper is to increase the transparency of energy flows in the carbon fibre value chain. To this end, the extended energy value stream methodology was modified and applied on a research scale polyacrylonitrilie precursor line and a pilot scale carbon fibre line. The paper takes in a holistic factory understanding when quantifying energy demands and it provides highly-detailed energy related data across the carbon fibre manufacturing process chain. Energy demands are broken down into energy carriers, process steps and peripheral levels of the carbon fibre production system. The results of the paper lay a first valuable step towards a comprehensive life cycle inventory of carbon fibre manufacturing. Furthermore, the high transparency of energy data provides a starting point for future research to increase the energy efficiency of carbon fibre manufacturing. With respect to the high share of the technical building services on the total energy demand, the paper emphasizes the need for an integrated assessment and improvement of the manufacturing process and technical building services.
The high growth usage of carbon and glass fibre reinforced polymer (CFRP and GFRP) composites has led to production of a substantial amount of FRP waste. Currently, landfilling and incineration are common waste treatment methods for FRP composites which may result in environmental issues and exploitation of raw materials. During the last decades, various recycling methods have been developed to provide more sustainable solutions for FRP waste management. This research evaluates the environmental and financial viability of ten different CFRP and GFRP waste treatment methods via life cycle analysis (LCA), cost benefit analysis (CBA) and the technology readiness level (TRL) assessment. The results from CBA analysis show that solvolysis provides the highest profit amongst FRP recycling treatment methods while its performance can vary when different chemical solutions are used. Two of thermal recycling methods such as pyrolysis and pyrolysis plus oxidation also show high return for investment. LCA is carried out based on cumulative energy demand (CED) and global warming potential impact (GWP) of each treatment methods. Results indicate that thermal recycling methods require low energy input to achieve reasonable economic benefit, while there is a large electricity demand required by electrochemical method for obtaining similar profit as thermal recycling. Global warming potential impact analysis shows that solvolysis and electrochemical methods can lead to reduction of greenhouse gases during life cycle of FRP. The outcomes of this research provide valuable guidelines for waste treatment selection and market outlook of CFRP and GFRP recycling techniques.
Electricity generated from tidal streams via underwater turbines has significantly lower greenhouse gas emissions than fossil-fuel derived electricity. However, tidal stream turbine blades are conventionally manufactured from non-recyclable reinforced polymer composite materials. Tidal stream capacity is forecast to be over 1GW by 2030, which using current methods will ultimately produce around 6000 tonnes of non-recyclable blade waste. This waste is currently disposed of in landfill or incinerated, both of which have greenhouse gas and human health impacts. To address a growing waste management problem, this high-level study considers for the first time a range of conventional and bio-based materials, manufacturing methods, and end-of-life treatments to determine the blade materials and designs likely to have low environmental impact. A finite element model is used to develop material cases and Life Cycle Assessment is used to study the impacts of each over a ‘cradle to dock, dock to grave’ scope. The impact of material choices on cost and modifications to the wider turbine are considered. Compared to a glass fibre composite turbine blade, steel blades are around 2.5 times heavier, and incur additional environmental impact due to upgrades required to the wider turbine. Carbon fibre composite blades weigh less than glass fibre, but cause greenhouse 80% greater gas emissions, and human and ecosystem health risks, so are also not recommended. The best environmental performance of the cases considered was a flax fibre composite. This material offers greenhouse gas emissions around 50% lower than glass fibre materials when manufactured using conventional epoxy resin, and around 40% lower when manufactured using recyclable epoxy resin, which also enables the reuse of the fibre and may further reduce environmental impact. Initial results suggest that the cost of these materials are similar to or lower than conventional composite materials.
Braided-textile composites have been applied in various engineering fields and used for high-efficiency energy absorbers to meet different loading requirements. However, it’s difficult to accurately forecast the mechanical properties of these braided-textile composites based on theoretical method, which is a big obstacle to the precise design of the energy-absorbing structure. In this research, carbon fiber reinforced composite (CFRC) tubular structures were fabricated by two-dimensional braided textiles, and 160 groups of orthogonal axial compression experiments were carried out.
Axial compression behaviors of CFRC tubular structures, including peak force, mean crushing force, energy absorption, specific energy absorption, elastic modulus and other relevant parameters, were tested and collected in a database. The feed forward back propagation (FFBP) algorithm based on artificial neural network (ANN), as an algorithm with high convergence accuracy in machine learning (ML), was adapted to build a prediction model to forecast the overall axial compression properties of those CFRC tubular structures uncollected in the database. By a series of error analyses, the ML method was proven to have high accuracy in predicting the relevant mechanical properties within the range of orthogonal design groups. Although the relative error of marginal sample data (especially single-layer tubes) is large, the mean absolute error (MAE) of training set and test set is only about 5% and 10%, respectively. Our work demonstrates the potential of machine learning methods in predicting the overall mechanical properties and guiding the design of composite materials.
Over past few decades composite materials, ceramics and plastics have been leading emerging materials. The applications of composite material and the area in which they are being used is growing day by day. The curiosity has gained substantially towards the use of natural fibres in composites in recent few decades. Natural fibre composites are eco-friendly and often used in engineering application such as in construction, automobile, aerospace and household applications. Nano fibres are responsible for a connection between the Nano scale and the macro scale, since their diameters are in the nanometre range and the length is continuous. Nanofibre are attracting very high interest due to their extraordinary micro and Nano structural characteristics, high porosity, mechanical strength, Flexibility and integrally large total surface area. There is increased curiosity about natural fibre based epoxy composites properties to short out engineering necessities. Hence, a matter of concern to overview and check the exiting position and put efforts for sustainable and possible commercial exploitation and additional improvements. This research work shows comparison of strengths with and without added Nano fibres to the Banana fibres composite. Testing data clearly indicates the enhancement in mechanical properties when Nano fibres are added in to Natural fibre reinforced composite.. keywords: Natural fiber composite, Nanocomposite, PAN Nanofiber.
Utilizing recycled or short fibers for making useful engineering composite component is a present research trend and requirement. Current research work explicates the effect of short carbon fibers (SCF) used as secondary reinforcement in woven glass/epoxy hybrid composites and evaluates their mechanical properties. Different concentrations (0.1, 0.3, and 0.5 wt%) of SCF were incorporated to assess the tensile, flexural, and interlaminar fracture toughness (Mode I and II) of the resulted composites. Composites with 0.1 wt% SCF showed 29.02% and 16.08% increment in the tensile and flexural strength, respectively. For Mode I and Mode II interlaminar fracture toughness tests, 0.1 wt% SCF‐GE samples showed the highest strain energy release rate. Double cantilever beam specimens were used for Mode I testing and an improvement of 13.49% in value was observed. End‐notched flexure method was used for the Mode II tests, and 0.1 wt% SCF‐GE samples showed 20.45% increase in values. This paper explains the various reasons and mechanisms for obtaining such results. Scanning electron microscopy of the fractured surfaces was carried out to perceive the diverse failure micro‐mechanisms that could have been involved.
In this study, the GHG emission of an advanced CF (carbon fiber) production process with flame resistant fibers was compared with that of the conventional CF production process with polyacrylonitrile (PAN)-based fibers. Cradle-to-gate LCA approach was taken. Up-scaling method was used to estimate GHG emissions from the lab scale to the production scale. The analysis concludes:
•The GHG emissions of the conventional CFs and the advanced CFs were evaluated using an upscaling method. The effect of upscaling was particularly significant with the production of flame-resistant fibers.
•The total GHG emission resulting from producing CFs by the conventional method and the advanced methods is 24.83 kg-CO2eq/kg and 19.29 kg-CO2eq/kg, respectively, when the production scale is 3000 TPY (ton per year), representing 20% GHG emission reduction.
•The main reason for this reduction is that the advanced CF technology enables liquid-phase stabilization in fiber preparation stage with the newly developed flame resistant fibers.
As shown in the above summary, this advanced process has great potential to reduce the GHG emissions of CFs.
In this chapter, the environmental performance of natural reinforcements is evaluated relative to their synthetic counterparts based on the recently published studies in the field. Most of the reviewed studies depend on the life cycle assessment approach to compare natural and synthetic reinforcements in terms of environmental impact (EI). The improvements achieved on the environmental performance of eco-friendly fibers reinforced composites should be linked with the developed composites’ mechanical properties along with costs of materials and end-of-life (EoL) treatment methods. The EI of synthetic fibers reinforced composites can be alleviated if the man-made fibers are recycled and reused to substitute fresh fibers in the synthetic composites. The substitution process’s economic feasibility is governed by the type of substituted fibers and the recycled fibers’ recovery rate. The incineration and landfilling treatments, which are frequently used to process synthetic composites’ wastes, should be avoided during the EoL phase due to releases of CO2 emissions and polluting elements to air and underground water. However, a modern incineration method with energy recovery has been developed in recent years, generating the energy needed to fabricate synthetic composites with the lowest possible amount of emissions. Significant quantities of greenhouse gases can be avoided when lightweight, eco-friendly natural fibers substitute synthetic heavy glass fibers in automotive and aerospace applications. It is noteworthy that the multiple recycling of natural and synthetic fibers makes them shorter and considerably affects their aspect ratios. Therefore, the damaged fibers can only be implemented in non-structural applications such as interior panels’ fabrications appropriate for buildings’ thermal insulation or vehicle furniture.
Der aktuelle Stand des Wissens und Umsetzungsvorschläge für die Praxis eines klimaverträglichen und ressourceneffizienten Bauens mit Beton sind die Inhalte dieses Beitrags. Das interdisziplinäre Autorenteam deckt das Spektrum von der angewandten Geologie über die Materialwissenschaften hin zum konstruktiven Beton‐ und Ingenieurbau ab. Nach einem Überblick über den aktuellen Stand der Forschung zum Thema des klimaverträglichen und nachhaltigen Bauens mit Beton werden ausführlich sowohl emissionsreduzierende Maßnahmen für die Bindemittel und Betonzusatzmittel als auch für die Gesteinskörnungen mit deren Möglichkeiten des Wiedereinsatzes aufgezeigt. Weiterhin werden innovative Möglichkeiten der Bewehrung mit Carbonfasern, der Topologieoptimierung von Tragstrukturen als auch Potenziale während des Bauablaufs vorgestellt und eingehend erläutert. Analog zu den Grenzzuständen der Tragfähigkeit und der Gebrauchstauglichkeit wird ein neuer Grenzzustand der Klimaverträglichkeit vorgeschlagen. Darin spiegelt sich auch das Potenzial einer verlängerten Lebensdauer wider. Wertvolle Informationen und aktualisierte Daten über die Umweltwirkungen einzelner Baustoffe, Konstruktionen und Bauprozesse wurden in Tabellenform oder Diagrammen zusammengefasst.
The world is facing the crucial energy transition and it will require a rapid growth of renewable energy production. Given the intermittency of renewable energy sources, though, the ambitious decarbonization goals cannot be achieved without the implementation of energy storage systems. In this scenario, redox flow batteries (RFBs) stand as promising candidates, where vanadium RFBs have been established as the technological standard. Nevertheless, RFB systems based on metals pose environmental, socio-political and ethical problems; therefore, research is seeking new safer and more sustainable redox materials, shifting attention from metal-based to organic-based electrolytes. To our knowledge, up to now, a complete environmental assessment of an organic or semi-organic electrolyte RFB has not been carried out. In this study, an organic/halogen RFB, based on anthraquinone disulfonic acid (AQDS) and hydrobromic acid (HBr), is analyzed via Life Cycle Assessment (LCA). Influence of materials production on environmental performance of the energy storage system is evaluated via two synthesis scenarios. Organic/halogen battery is compared with an equivalent vanadium-based battery, taken as a standard reference for RFB technology. The analysis shows that the production of a semi-organic RFB may represent a valid environmental alternative to full vanadium RFB, as smaller effects in several impact categories (Recipe 2016) are determined. Nevertheless, LCA analysis showed that the results are strongly dependent on the synthetic route adopted to produce AQDS. As a result of such work a greener chemical pathway is open toward the benefits of switching from metal to organic RFBs.
This paper presents an innovative, eco-friendly and sustainable tape manufacturing technology that transforms waste carbon and polyamide fibers into a new class of fibrous structure with unidirectional fiber orientation, termed “unidirectional tapes structure” for the fabrication of high performance composites. This novel technology imparts homogeneity, uniformity, orientation and thermal stability in unidirectional tapes structure that resemble conventional prepreg material. Unidirectional configuration of the tapes structure brings a revolution towards development of cost efficient carbon fiber composites for load bearing structural applications. This paper introduces the concept of tape manufacturing technology and highlights the modifications, optimization, and technological developments carried out to develop unidirectional tapes. The structural parameters that play a significant role in the properties of the high-performance composite, such as fiber length, fiber orientation, fiber damage, and uniformity, were assessed during tape manufacturing. The results reveal composites fabricated from unidirectional tape structures with optimum parameters deliver tensile strength and modulus of 1370 ± 22 MPa and 85 ± 4 GPa, respectively.
Selection of recycling approaches is one of the remaining issues in the life cycle assessment (LCA) and a critical factor for materials selection based on the LCA. While several recycling approaches and allocation methods have been proposed, the impact of the recycling effect determined by different allocation methods on materials selection has yet to be addressed. In this study, we demonstrate the impact of the recycling effect on materials selection in the LCA. First, the appropriateness of the avoided burden approach for the purpose of materials selection is addressed and practical equations for the three typical allocation methods in the avoided burden approach are proposed, for waste mining, end-of-life recycling, and 50-50 methods. Next, a material flow analysis is used to justify the recycling parameters associated with each allocation method. Finally, an LCA case study on different materials used for the light-weighting vehicle is conducted to show the impact of recycling effect on materials selection. According to the results of the life cycle greenhouse gas emissions, for the battery electric vehicles manufactured with intensive use of different materials, the preferred material is different depending on the waste mining and end-of-life recycling methods selected. Due to the different greenhouse gas emissions during the use phase, the recycling effect in the life cycle of battery electric vehicles is more substantial than that of internal combustion engine vehicles. The results of this study clearly indicate that attention should be given to the recycling effect when an LCA study is conducted for materials selection, especially when considering the products associated with a heavy environmental burden in the production phase. Future work on the development of a concrete selection methodology for different allocation methods is necessary. In addition, a high-resolution material flow analysis would be useful to obtain values of the part-specific recycled content of the designated product to ensure transparency and fairness when quantifying the recycling effect.
Cellulose in particular and phytomass in general are at the heart of our food system. They are also a central energy vector and a vital source of materials. In this article, a multiscale approach to the complex issue of lignocellulose sustainability is developed. Global thermodynamic concepts help to place current biomass exploitation in a global energetic context. In particular, the notion of entropy appears pivotal to understand energy and material fluxes at the scale of the planet and the limits of biomass production. Entropy is, however, best described at the microscopic scale, despite its large-scale consequences. Recent advances in entropy-driven colloid assembly parallel nature's choices and lignocellulose assembly at the nanometric scale. The functional concept of exergy is then developed and a few examples of its concrete use in photosynthesis and biorefinery research are given. In a subsequent part, an evaluation of the relative importance of biomass is performed with respect to non-renewable materials. This discussion helps to explain the interdependence of resources, including ores and fossil fuels. This interdependence has important consequences for current and future biomass uses. Some of these dependences are then quantitatively discussed using life cycle analysis (LCA) results from the literature. These results are of importance to different technological fields such as paper, biobased insulation, construction wood, information and communication technologies, and biobased textiles. A conclusion is then drawn that exposes the research tracks that are the most likely to be sustainable, including self-assembly, exergetically favourable options and low tech solutions.
This paper explores the application of a novel adaptive consolidation sensor framework for the characterisation of composite precursors. The designed framework develops material-driven test programmes in real-time and defines robust material models for the studied composite precursor. The proposed approach allows to remove any subjective judgement about the material behaviour and to reduce human involvement at the experimentation stage. The proposed framework along with the developed data transfer/acquisition hardware setup was put to the test within several characterisation exercises. Two different material systems were tested. The output of the proposed testing method—model and properties for the tested materials—is compared with the results of the conventional deterministic characterisation tests.
The production and consequential waste of carbon fiber reinforced polymers (CFRP) is increasing owing to its utilization in various industries like automotive, aviation, electronics, military, sporting goods, etc. Likewise, the production of cementitious composites and related environ- mental concerns are also increasing. Therefore, research institutions and scientific groups are constantly looking for waste materials to be incorporated in cementitious composites to manage waste and promote sustainable development in the construction industry. Furthermore, conven- tional cementitious composites have low ductility, energy absorption capacity, and tensile strength. To counter these deficiencies, an alternative is to add steel rebars in cementitious com- posites, but it increases the risk of corrosion. As per the research studies, the incorporation of re- cycled CFRP (rCFRP) in cementitious composites can counter all the mentioned problems. There- fore, this study critically analyses the resourceful ways of recycling CFRP waste and the effect of rCFRP on the properties of cementitious composites. The properties discussed include workabil- ity, mechanical properties (i.e., compressive strength, flexural, strength, and tensile strength), impact resistance, electrical conductivity, and microstructure. Moreover, sustainability benefits and critical challenges of preparing rCFRP reinforced cementitious composites are also discussed comprehensively. The results reveal that the workability of cementitious composites decreases with increasing percentage incorporation of CFRP, thus, the suggested percentage addition is 0.25%. However, the addition of 0.25–1% rCFRP positively influences the mechanical properties and impact resistance of cementitious composites owing to the dense microstructure offered by rCFRP. In the case of electrical conductivity of cementitious compositions, the addition of 0.2–0.8% rCFRP is beneficial. It is also concluded that the addition of rCFRP promotes sustain- able development, however, open issues and challenges related to the recycling of CFRP and properties of rCFRP modified cementitious composites (particularly durability properties) need further investigation.
The performance of biobased carbon fiber (CF) can potentially be improved to a new level by enhancing its graphitization by including graphitic additives as structural templates in the precursor. Mixing these additives in the precursor spinning solution can influence the solution rheology and thus its spinning process and ensuing carbonization, though these effects are not well understood. Herein, we analyze the influence of carbon nanotube (CNT) and graphene oxide (GO) additives on the rheology of cellulose solutions in ionic liquid as well as the subsequent precursor and CF preparation. Addition of GO both thickened the solution and clearly increased its elastic (solid‐like) nature in comparison to pure cellulose solution in ionic liquid, while CNT only made the solution moderately more elastic. Still, solutions with both additives were spinnable into continuous precursor fibers, though the inclusion of GO somewhat disturbed cellulose alignment in the fiber, as observed through X‐ray diffraction. In addition, GO induced structural order development, observed as a decrease in the intensity and ratio between the Raman peaks at ~1300 cm−1 (related to disorder) and ~1600 cm−1 (related to sp2‐hybridized carbon in general). This study demonstrates the preparation of hybrid fibers out of cellulose and carbon nanomaterials in ionic liquid, including analysis of their rheological properties, which strongly influence their spinning process. Carbon nanotubes are shown to only subtly thicken the dispersion, while graphene oxide can interact more strongly with cellulose and produce a more rigid network.
Due exceptional properties such as its high-temperature resistance, mechanical characteristics, and relatively lower price, the demand for carbon fiber has been increasing over the past years. The widespread use of carbon-fiber-reinforced polymers or plastics (CFRP) has attracted many industries. However, on the other hand, the increasing demand for carbon fibers has created a waste recycling problem that must be overcome. In this context, increasing plastic waste from the new 3D printing technology has been increased, contributing to a greater need for recycling efforts. This research aims to produce a recycled composite made from different carbon fiber leftover resources to reinforce the increasing waste of Polylactic acid (PLA) as a promising solution to the growing demand for both materials. Two types of leftover carbon fiber waste from domestic industries are handled: carbon fiber waste (CF) and carbon fiber-reinforced composite (CFRP). Two strategies are adopted to produce the recycled composite material, mixing PLA waste with CF one time and with CFRP the second time. The recycled composites are tested under tensile test conditions to investigate the impact of the waste carbon reinforcement on PLA properties. Additionally, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier-transformed infrared spectroscopy (FTIR) is carried out on composites to study their thermal properties.
Techno-Economic Analysis (TEA) and Life Cycle Assessment (LCA) were performed on the Aqueous Lignin Purification with Hot Agents (ALPHA) process, which is being investigated for the fractionation and purification of raw, bulk lignins recovered from cellulosic ethanol biorefineries or Kraft pulp mills. Here, ALPHA is proposed for the isolation of lignin from a corn stover-to-ethanol plant into purified low, medium, and high molecular weight (MW) fractions for producing polyurethane foam, activated carbon, and carbon fiber, respectively. A scenario analysis was conducted to determine the effect of ALPHA solvent choice on process economics and environmental performance. Solvent choice was found to have a significant impact on ALPHA, with a minimum selling price of $838/tonne with use of acetic acid vs $463/tonne with ethanol. Conversion of the lignin, processed with ethanol solvent, to high-value products yields $151 million/year in profit, which over 30 years results in a total net present value of $533 million. A life cycle assessment was conducted to determine the "gate-to-gate"greenhouse gas emissions and energy consumption of the lignin-based products compared to fossil-based equivalents. A value allocation scenario was conducted and it was determined that products generated using the ALPHA process with ethanol have similar or lower greenhouse gas emissions than the same products from fossil feedstocks.
A variety of composite wastes were pyrolysed in a bench-scale, static-bed reactor at 350–800 °C. The samples under investigation included composites of polyesters, phenolic and epoxy resins, and polypropylene, reinforced with glass and/or carbon fibre. Both the product mass balance and gas composition were dependent on the polymer matrix, pyrolysis temperature and, at the higher temperatures studied, the decomposition of thermally unstable fillers present in several samples, most notably calcium carbonate. The waste samples were also pyrolysed in a thermo-gravimetric analyser and the Arrhenius kinetic parameters of the main decomposition reactions were calculated using a non-isothermal method. The thermograms are discussed in relation to the results of the bench-scale work and related to the decomposition behaviour of individual sample components.
Processes that produce only ethanol from lignocellulosics display poor economics. This is generally overcome by constructing large facilities having satisfactory economies of scale, thus making financing onerous and hindering the development of suitable technologies. Lignol Innovations has developed a biorefining technology that employs an ethanol-based organosolv step to separate lignin, hemicellulose components, and extractives from the cellulosic fraction of woody biomass. The resultant cellulosic fraction is highly susceptible to enzymatic hydrolysis, generating very high yields of glucose (>90% in 12-24 h) with typical enzyme loadings of 10-20 FPU (filter paper units)/g. This glucose is readily converted to ethanol, or possibly other sugar platform chemicals, either by sequential or simultaneous saccharification and fermentation. The liquor from the organosolv step is processed by well-established unit operations to recover lignin, furfural, xylose, acetic acid, and a lipophylic extractives fraction. The process ethanol is recovered and recycled back to the process. The resulting recycled process water is of a very high quality, low BOD5, and suitable for overall system process closure. Significant benefits can be attained in greenhouse gas (GHG) emission reductions, as per the Kyoto Protocol. Revenues from the multiple products, particularly the lignin, ethanol and xylose fractions, ensure excellent economics for the process even in plants as small as 100 mtpd (metric tonnes per day) dry woody biomass input a scale suitable for processing wood residues produced by a single large sawmill.
Greenhouse gases, regulated emissions, and energy use in transportation (GREET) excel model has been developed by Argonne National Labs for estimating the full fuel-cycle energy and emission impacts of various transportation fuels and vehicle technologies. It calculates fuel-cycle energy use in Btu/mi and emissions in g/mi for various transportation fuels and vehicle technologies. For energy use, GREET includes total energy use (all energy sources), fossil energy use (petroleum, natural gas, and coal), and petroleum use. For emissions, the model includes three major greenhouse gases (CO2, CH4, and N2O), and five criteria pollutants (VOC, CO, NOx, particulate matter with a diameter of ≤ 10 micrometers, and SOx). A stochastic simulation tool was developed to simplify setting up and executing a stochastic simulation for any Excel model. This tool was applied to the GREET model and compared the performance of the sampling techniques for selected output variables with different number of samples. This is an abstract of a paper presented at the AIChE Annual Meeting (San Francisco, CA 11/12-17/2008).
Carbon fiber reinforced plastics (CFRP) have successfully been used in aerospace applications to replace heavier materials, because of their light weight, high strength and high rigidity. Although we strongly need the same benefits in automotive applications, the high price and the difficulty of the recycling process have inhibited its widespread use in the automotive industry, in particular mass-produced passenger cars. However, in the last few years, much work has been done in developing lower-cost CFRP. We thus used life cycle assessment (LCA) and calculated how much the environmental burden of conventional steel cars changed when we replaced steel with CFRP whose performance was proper for mass-produced passenger cars, and in addition when we recycled CFRP. Replacing steel with CFRP in bodies, chassis and equipment, we considered three cases: (1) Use of only CF/EP (Its matrix is epoxy, which is thermosetting.), (2) Use of CF/EP and CF/PP (Its matrix is polypropylene, which is thermoplastic.), (3) (2) and recycled CF/PP. For the assessment, a gasoline passenger car, with a total weight of 1380 kg, and with a useful lifetime of 91720 km, was chosen as the functional unit. The reference flow was a car that fulfilled the functional unit. The system boundary included four stages: material production, vehicle production, use, and end-of-life. The impact category was energy consumption. As a result, the energy consumption reduced by 17%, 21%, 25% in the case of (1), (2), and (3) respectively. Therefore we conclude that CFRP is good for reducing environmental burdens of passenger cars, and in addition that the flexible use of CFRP, in accordance with performance that car parts demand, and recycling process are very important. INTRODUCTION Progress of fuel efficiency is strongly needed to reduce environmental burdens in the transport sector. Lightening vehicles is a very important technology that can contribute to easing the burden. In recent years, carbon fiber reinforced plastics (CFRP) have attracted a lot of attention as light materials. As shown in Figure 1, CFRP have such a high specific strength and specific rigidity that we have been using them for airplanes, rockets, etc. Although we strongly need the same benefits in automotive applications, the high price and the difficulty of the recycling process have inhibited its widespread use in the automotive industry, in particular in mass-produced passenger cars. However, in the last few years, the amount of CFRP production has been increasing and much work has been done in developing lower-cost CFRP, which has lead to the improved probability of using CFRP for mass-produced cars. The energy-saving effect of CFRP during the life cycle, however, might be small because CFRP need large energy resources when they are produced. We, thus, used the life cycle assessment (LCA) and calculated how much the environmental burden of conventional steel cars changed when we replaced steel with CFRP whose performance was proper for mass-produced passenger cars. In addition, we use the new energy intensity of CFRP that was recalculated last year [1]. In this LCA, our database of energy intensity was so imperfect that the impact assessment was very difficult. Thus we only carried out an inventory analysis (LCI).
Carbon fiber reinforced plastics (CFRP) have recently attracted much attention as light materials in the automotive industry, in particular in mass-produced passenger cars. However, the large energy consumption, the difficulty of the recycling process, and the high cost have inhibited its widespread use in general industrial field. So, we have to decrease the energy intensity of production to the level of steel and reduce the initial cost in order to use CFRP for mass-produced passenger cars. Up to now, CFRP that we have discussed has been for aircrafts, so it has been very advanced and its energy intensity has been much larger than that of steel. So, in this study, we calculated energy intensity of CFRP whose specification was for mass-produced cars by use of energy intensity of carbon fiber (CF) that was newly calculated some years ago. After calculating, it was still much larger than that of steel when only virgin CF was used, though it decreased dramatically when we rightly chose fiber fraction and a kind of matrix resin. 3R (reduce, reuse, and recycle) technology, thus, was very important. We found that the effective combination of the 3R could decrease the energy intensity of CFRP to the level of steel parts.
The detailed heat and material balances which are presented in this book were developed from process flow diagrams of 108 industrial processes, with technical input from consultants and manufacturers, and on-site verification studies. Data such as process temperature, pressure, fuel requirements, thermal efficiency and radiation, and convection losses are determined for varying industrial operations spanning the food products, textile, lumber and wood, paper, chemical, petroleum, rubber and plastics, glass, metals, machinery, transportation equipment, and instrument manufacturing industries.
The Department of Energy Partnership for a New Generation of Vehicles has shown that, by lowering overall weight, the use of carbon fiber composites could dramatically decrease domestic vehicle fuel consumption. For the automotive industry to benefit from carbon fiber technology, fiber production will need to be substantially increased and fiber price decreased to $7/kg. To achieve this cost objective, alternate precursors to pitch and polyacrylonitrile (PAN) are being investigated as possible carbon fiber feedstocks. Additionally, sufficient fiber to provide 10 to 100 kg for each of the 13 million cars and light trucks produced annually in the U.S. will require an increase of 5 to 50-fold in worldwide carbon fiber production. High-volume, renewable or recycled materials, including lignin, cellulosic fibers, routinely recycled petrochemical fibers, and blends of these components, appear attractive because the cost of these materials is inherently both low and insensitive to changes in petroleum price. Current studies have shown that a number of recycled and renewable polymers can be incorporated into melt-spun fibers attractive as carbon fiber feedstocks. Highly extrudable lignin blends have attractive yields and can be readily carbonized and graphitized. Examination of the physical structure and properties of carbonized and graphitized fibers indicates the feasibility of use in transportation composite applications.
Because of their high strength-to-weight ratios, carbon-fiber-reinforced polymer-matrix composite (PMC) materials are being
evaluated for use in the automotive industry. The major barriers to their widespread use are their relatively high cost and
the uncertainty about whether they can be recycled. A process to recover carbon fibers from obsolete PMC materials has been
developed at Argonne National Laboratory. The process was tested using PMC samples made with different thermoset or thermoplastic
substrates. For most mixtures of PMCs, the process can be energy self-sufficient using the polymer substrate as an energy
source. An evaluation of the recovered samples found that the fibers appear to have retained good properties and characteristics
and are suitable for short fiber applications. This paper describes the process and the characteristics and properties of
the recovered fibers.
Lignin samples, sub-product in the Kraft process of cellulose from eucalyptus wood, were burnt in a laboratory scale furnace at different residence temperatures and with distinct fuel-rich atmospheres. The yields of CO, CO(2), eight light hydrocarbons (methane, ethylene, ethane, propylene, acetylene, butane, etc.) and 60 semi-volatile+volatile compounds (benzene, toluene, ethylbenzene, styrene, indene, naphthalene, dibenzofuran, phenanthrene, chrysene, etc.) were determined, with nominal reactor temperatures between 800 and 1100 degrees C and residence times of the volatiles evolved and formed between 4 and 7 s. The collection of the gases and volatiles evolved was carried out with a Tedlar bag and by XAD-4 resin respectively, comparing the data obtained in both cases. The emission factor (mg/kg) of the CO was between 2500 and 90000, and under the poor-oxygen atmosphere, the emission factors of many by-toxic products were greater than 100 mg/kg. A pyrolysis run was also performed, obtaining emission factors between 30 and 3000 mg/kg, facilitating its identification. The behaviour of different compounds in the combustion runs was discussed considering three groups in accordance with their stability vs. oxygen, and two groups vs. temperature.
ND) LCA of passenger vehicles lightened by recyclable carbon fiber reinforced plastics Automotive composites consortium focal project 4 GREET 1.8b: The greenhouse gases, regulated emissions, and energy use in transportation (GREET) model. Center for Transportation Research
- T T Odai
- R Hukui
- Takahashi
T, Odai T, Hukui R, Takahashi J (ND) LCA of passenger vehicles lightened by recyclable carbon fiber reinforced plastics. http://sunshine.naoe.t.u-tokyo.ac.jp. Accessed 9 September 2008 US Department of Energy (DOE) (2008) Automotive composites consortium focal project 4. Automotive Lightweighting Materials: FY 2007 Progress Report, Washington, DC Wang MQ (2008) GREET 1.8b: The greenhouse gases, regulated emissions, and energy use in transportation (GREET) model. Center for Transportation Research, Argonne National Laboratory, Argonne, IL, Mar. 17
Results review: Technical cost model development for structural composite underbody. Presen-tation made to the ACC Composite Underbody Program
- Associates
- Inc
Associates, Inc. (Ibis) (2007). Results review: Technical cost model development for structural composite underbody. Presen-tation made to the ACC Composite Underbody Program, Waltham, Massachusetts, Nov. 25
GREET 1.8b: The greenhouse gases, regulated emissions, and energy use in transportation (GREET) model. Center for Transportation Research
- Mq Wang
An approach to treatment of recycling in LCA. Paper presented at the 4th Australian LCA Conference
- A Koltun
The new face of CAFÉ. Ward’s Autoworld February
- T Murphy
SimaPro 7.1.7 LCA software. Pre Consultants, The Netherlands
- Simapro
Carbon-reinforced composite recycling: process and business development
- R E Allred