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Déchets verre, waste

An oasis of waste reconverted into ceramic materials

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Transforming industrial waste and unused by-products could make it possible to respond to issues of scarcity for civil engineering resources, recyclability and even reducing use of fossil fuels. Doan Pham Minh, process engineering researcher at IMT Mines Albi, explains several avenues for recycling and reusing materials explored by his work.

One man’s trash can be another man’s treasure. Turning rubbish into resources is the aim of the circular economy. And it is also the issue at the heart of the Innovative Ceramic Materials for Energy Storage and Construction (MACISEB)[1] project, launched in 2019, with the participation of researchers from IMT Mines Albi[2]. “Our objective is to transform inorganic, industrial waste and by-products, which can be found around us, into something that is useful for society,” describes Doan Pham Minh, process engineering researcher. The solutions identified as part of the project will then be transferred to companies in the Occitania region. From finding other uses for unrecyclable waste to replacing raw materials that are running out, the principle of ‘second life’ can be applied to a large range of unexpected situations.

Sand reserve seeks replacement for time to rest and recuperate

The French Agency for Ecological Transition (Ademe) reports that between 27 and 40 billion tons of sand are extracted each year around the world. It can be found in our buildings and windows, as well as our computers. “The demand for this resource is even more critical than that for noble metals. And the reserves are running out so quickly that they are arriving at breaking point,” emphasizes Pham Minh. Extracted from quarries or taken from riverbeds, natural sand is formed by the lengthy process of erosion. Too long, therefore, to meet society’s needs. However, this material is indispensable for the civil engineering sector (its main consumer) and therefore the economic stability of many countries.

Read more on I’MTech: Sand, an increasingly scarce resource that needs to be replaced

This is why the MACISEB project is seeking sand replacement products from inorganic by-products, i.e. industrial waste that is not currently being used. “The idea is not to completely change our means of manufacturing, but to replace a critical raw material using a circular economy approach,” specifies Pham Minh. With his team, the researcher has created resource maps for the entire Occitan territory. He identified and located deposits with high potential and similar properties to sand. He also ensured that these products are sustainable, by noting the quantity and availability of this waste. In this way, multiple candidates were selected, including glass residue.

During the recycling process, glass is ground up into grains fine enough to be reused by glass factories. However, a portion of this glass, too fine, coarse or contaminated, is not reused. “We are recovering this leftover glass to replace part or all of the sand needed to make ceramic bricks or tiles,” specifies Pham Minh. Sand from foundries, slag from blast furnaces, and ashes from biomass thermal power plants are also promising.

Using these materials, researchers have suggested formulas to create bricks and tiles with the same mechanical and thermal properties as those made with clay and natural sand. Moreover, the formulas comply with industrial specifications. The products are therefore guaranteed to be able to be manufactured using equipment that companies already possess, without extra investment. The first bricks will be made in 2022, and then tested by the Scientific and Technical Center for Building (CSTB).

From wind to heat: reusing wind turbine blades

The operating lifespan of a wind turbine is estimated at around twenty years. This means that the first French facilities are now arriving at end-of-life, and there will have to be more dismantling in the coming years. In short, recycling is becoming a major challenge for the wind energy industry. While the parts made from metal (pole and rotor) and concrete (base) recycle well, the blades – made from glass fiber mixed with organic resin – are not so lucky. Another part of the MACISEB project involves researchers recycling this waste into thermal storage materials. “Our objective is to reuse glass fiber from the blades to develop ceramics used by concentrated solar power (CSP) plants,” explains the researcher. This means of energy production transforms solar energy first into heat, then electricity. To do so, it uses systems made up of mirrors that concentrate the sun’s rays at one point, generating extremely high temperatures (from 200 to 1,500°C). The heat is transported by fluid, to propel the turbines and produce. It can be stored in ‘thermal batteries’, to later be released during the night to ensure continuity of service.

At present, thermal power plants store heat using molten salt – a mixture of potassium nitrate and sodium nitrate. “These compounds can also be found in agricultural fertilizer. There is therefore a conflict of use between the two sectors. However, there is currently no commercial alternative that is economically and environmentally viable,” explains Pham Minh. Transforming turbine blades into ceramics would therefore provide a new solution for this sector. With this in mind, researchers are developing materials capable of handling intense, repeated cycles of heating and cooling for multiple years. This solution would eventually make it possible to reuse a waste product that promises to grow. But it will also give a technological boost to the thermodynamic solar energy sector, which could allow it to establish itself in the renewable energy market. As part of the MACISEB project, this research is being undertaken by the PROMES laboratory, a partner of the project and academic reference body in the area of thermal storage. ART-DEV, partner and social sciences laboratory, is also looking into the social conditions for recycling wind turbine blades and the possibility of implementing a recycling ecosystem for the blades at a regional scale.

Industrial fumes: an idea to get the turbines going

Another application could make use of ceramic materials made from inorganic waste to capture heat. At present, the industry squanders over 30% of the energy it consumes in the form of so-called waste heat, released into the atmosphere in industrial fumes. Researchers at IMT Mines Albi are collaborating with company Eco-Tech Ceram, specialist in thermal storage, in order to recover this energy, store it and use it to supply industrial processes. For example, ceramicists and metal-working factories use high-temperature ovens, often running on natural gas. Reusing the heat captured from their fumes would make it possible to partially heat their equipment and therefore reduce their fossil fuel consumption.

Like for thermodynamic solar, the challenge is therefore to develop ceramic materials adapted for companies’ conditions of use. “Nevertheless, here another issue arises: industrial fumes contain pollutants. Such acidic, corrosive gases accelerate the aging of ceramics and therefore alter their performance,” explains the researcher. Moreover, the composition of fumes varies according to the industrial operations. The first thing to do will therefore be to characterize the kind of fumes, their temperature, etc. sector by sector, in order to develop sustainable materials while keeping costs under control[3].

Anaïs Culot

[1] Project funded by the European Regional Development Fund (ERDF), part of European policy aiming to strengthen economic, social and territorial cohesion in the European Union by supporting development in regions such as here, in the Occitania region.
[2] The project brings together researchers from the RAPSODEE center, the PROcesses, Materials and Solar Energy (PROMES) laboratory, the Actors, Resources and Territories in Development (ART-DEV) laboratory and the company Eco-Tech Ceram.
[3] This is part of the objectives of certain projects, Eco-Stock® solutions to recycle complex industrial waste heat (SOLUTEC, launched in 2021) and developing monolithic materials from local clay blends to reuse industrial waste heat in Occitania (CHATO, launched in 2021), led by IMT Mines Albi.
gestion des déchets, waste management

Waste management: decentralizing for better management

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Reducing the environmental impact of waste and encouraging its reuse calls for a new approach to its management. This requires the modeling of circuits on a territorial scale, and the improvement of collaboration between public and private actors.

Territorial waste management is one of the fundamental aspects of the circular economy. Audrey Tanguy,1 a researcher at Mines Saint-Étienne, is devoting some of her research to this subject by focusing on the development of approaches to enable the optimal management of waste according to its type and the characteristics of different territories. “The principle is to characterize renewable and local resources in order to define how they can be processed directly on the territory,” explains Audrey Tanguy. Organic waste, for example, should be processed using the shortest possible circuits because it degrades quickly. Current approaches tend to centralize as much waste as possible with a view to its processing, while circular approaches tend towards more local, decentralized circuits. Decentralization can be supported by low-tech technologies, which optimize local recycling or composting in the case of organic waste, especially in the urban environment.

The research associated with waste processing therefore aims to find ways to relocate these flows. Modeling tools can help to spatialize these flows and then provide guidance for decision-makers on how to accommodate local channels. “Traditional waste-processing impact assessment tools assess centralized industrial systems, so we need to regionalize them,” explains Audrey Tanguy. These tools must take the territorial distribution of resources into account, regardless of whether they are reusable. In other words, they must determine which are the main flows that can be engaged in order to recover and transform materials. “It is therefore a question of using the appropriate method to prioritize the collection of materials, and to this end, an inventory of the emission and consumption flows needs to be drawn up within the territory,” states the researcher.

Implementation of strategies in the territories

In order to implement circular economy strategies on a territorial scale, the collaboration of different types of local actors is essential. Beyond the tools required, researchers and the organizations in place can also play an important role by helping the decision-makers to carry out more in-depth investigations of the various activities present in the chosen territory. This enables the definition of collaborative strategies in which certain central stakeholders galvanize the actions of the other actors. For example, business associations or local public-private partnership associations promote policies that support industrial strategies. A good illustration is the involvement of the Macéo association, in partnership with Mines Saint-Étienne, in the implementation of strategies for the recycling and recovery of plastic waste in the Massif Central region. It acts as a central player in this territory and coordinates the various actions by implementing collaborative projects between companies and communities.

The tools also provide access to quantitative data about the value of potential exchanges between companies and enable the comparison of different scenarios based on exchanges. This can be applied to aspects of the pooling of transport services, suppliers or infrastructure. Even if these strategies do not concern core industrial production activities, they lay the foundations for future strategies on a broader scale by establishing trust between different actors.

Reindustrialisation of territories

“We assume that in order to reduce our impacts, one of the strategies to be implemented is the reindustrialization of territories to promote shorter circuits,” explains Natacha Gondran,1 a researcher in environmental assessment at Mines Saint-Étienne. “This may involve trade-offs, such as sometimes accepting a degree of local degradation of the measured impacts in exchange for a greater reduction in the overall impact,” the researcher continues.

Reindustrializing territories is therefore likely to favor the implementation of circular dynamics. Collaboration between different actors at the local level could in this way provide appropriate responses to global issues concerning the pressure on resources and emissions linked to human activities. “This is one of the strategies to be put in place for the future, but it is also important to rethink our relationship with consumption in order to reduce it and embrace a more moderate approach,” concludes Natacha Gondran.

1 Audrey Tanguy and Natacha Gondran carry out their research in the framework of the Environment, City and Society Laboratory, a joint CNRS research unit composed of 7 members including Mines Saint-Étienne.

Antonin Counillon

This article is part of a 2-part mini-series on the circular economy.
Read the previous article:

Economics – dive in, there is so much to discover!
économie circulaire, impact environnemental

Economics – dive in, there is so much to discover!

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To effectively roll out circular economy policies within a territory, companies and decision-makers require access to evaluation and simulation tools. The design of these tools, still in the research phase, necessarily requires a more detailed consideration of the impact of human activities, both locally and globally.

“The circular economy enables optimization of the available resources in order to preserve them and reduce pressure on the environment,” explains Valérie Laforest,1 a researcher at Mines Saint-Étienne. Awareness of the need to protect the planet began to develop in earnest in the 1990s and was gradually accompanied by the introduction of various key regulations. For example, the 1996 IPPC (Integrated Pollution Prevention and Control) Directive, which Valérie Laforest helped to implement through her research, aims to prevent and reduce the different types of pollutant emissions. More recently, legislation such as the French Law on Energy Transition for Green Growth (2015) and the Anti-Waste Law for a Circular Economy (2021) have reflected the growing desire to take the environment into account when considering anthropic activities. However, to enable industries to adapt to these regulations, it is essential for them to have access to tools derived from in-depth research on the impacts of their activities.

Decision-support tools for actors

To enable actors to comply with the regulations and reduce their impacts on the environment, they need to be provided with tools adapted to issues that are both global and local. Part of the research on the circular economy therefore concerns the development of such tools. The aim is to design models that are precise enough to be able to characterize and evaluate a system on the scale of an individual territory, while also being general enough to be adapted to territories with other characteristics. Fairly general methodological frameworks can therefore be developed, within which it is possible to determine criteria and indicators specific to certain cases or sectors. These tools should provide decision-makers with the information they need to implement their infrastructures.

At Mines Saint-Étienne and in collaboration with Macéo, a team of researchers is focusing on the development of a tool called ADALIE, which aims to characterize the potential of territories. This tool creates maps of different geographical areas showing different criteria, such as the economic or environmental criteria of these territories, as well as the industries established in them and their impacts. Decision-makers can therefore use this mapping tool as the basis for choosing their priority activity areas. “The underlying issue is about being able to ensure that a territory possesses the dimensions required to implement circular economy strategies, and that they are successful,” Valerie Laforest tells us. In its next phase, the ADALIE program then aims to archive experiences of effective territorial practices in order to create databases.

For each territorial study, the research provides a huge volume of different types of information. This data generates models that can then be tested in other territories, which also enables the robustness of the models to be checked according to the chosen indicators. These types of tools help local stakeholders to make decisions on aspects of industrial and territorial economics. “This facilitates reflection on how to develop strategies that bring together several actors affected by different issues and problems within a given territory,” states Valérie Laforest. To this end, it is essential to have access to methodologies that enable the measurement of the different environmental impacts. Two main methods are available.

Measurements of impact on the circular economy

Life cycle analysis (LCA) aims to estimate environmental impacts spanning a large geographical and temporal scale, taking account of issues such as distance transported. LCA seeks to model all potential consumptions and emissions over the entire life span of a system. The models are developed by compiling data from other systems and can be used to compare different scenarios in order to determine the scenario that is likely to have the least impact.

Read more on I’MTech: What is life cycle analysis?

The other approach is the best available techniques (BAT) method. This practice was implemented under the European Industrial Emissions Directive (IPPC then IED) in 1996. It aims to help European companies achieve performance standards equivalent to benchmark values for their consumption and emission flows. These benchmarks are based on data from samples of European companies. The granting or refusal of an operating license depends on the comparison of their performance with the reference sample. BATs are therefore based on European standards and have a regulatory purpose.

BATs are related to companies’ performance in the use phase, i.e. the performance of techniques is closely scrutinized in relation to incoming and outgoing flows during the use phase. LCA, on the other hand, is based on real or modeled data including information from upstream and downstream of this use phase. The BAT and LCA approaches are therefore complementary and not exclusive. For example, between two BAT analyses of a system to ensure its compliance with the regulations, different models of the systems could be created by conducting LCAs in order to determine the technique that has the least impact throughout its entire life cycle.

Planetary boundaries

In addition to quantifying the flows generated by companies, impact measurements must also include the effects of these flows on the environment on a global scale.

To this end, research and practices also focus on the effects of activities in relation to the different planetary boundaries. These boundary levels reflect the capacity of the planet to absorb impacts, beyond which they are considered to have irreversible effects.

The work of Natacha Gondran1 at Mines Saint-Étienne is contributing to the development of methods for assessing absolute environmental sustainability, based on planetary boundaries. “We work on the basis of global limitations, defined in the literature, which correspond to categories of impacts that are subject to thresholds at the global level. If humanity exceeds these thresholds, the conditions of life on Earth will become less stable than they are today. We are trying to implement this in impact assessment tools on the scale of systems such as companies,” she explains. These impacts, such as greenhouse gas emissions, land use, and the eutrophication of water, are not directly visible. They must therefore be represented in order to identify the actions to be taken to reduce them.

Read more on I’MTech: Circular economy, environmental assessment and environmental budgeting

Planetary boundaries are defined at the global level by a community of scientists. Modeling tools enable these boundaries to be used to define ecological budgets that correspond, in a manner of speaking, to the maximum quantity of pollutants that can be emitted without exceeding these global limits. The next challenge is then to design different methods to allocate these planetary budgets to territories or production systems. This makes it possible to estimate the impact of industries or territories in relation to planetary boundaries. “Today, many industries are already exceeding these boundary levels, such as the agri-food industry associated with meat. The challenge is to find local systems that can act as alternatives to these circuits in order to drop below the boundary levels,” explains the researcher. For example, it would be wise to locate livestock production closer to truck farming sites, as livestock effluents could then be used as fertilizer for truck farming products. This could reduce the overall impact of the different agri-food chains on the nitrogen and phosphorus cycles, as well as the impact of transport-related emissions, while improving waste management at the territorial level.

Together, these different tools provide an increasingly extensive methodological framework for ensuring the compatibility of human activities with the conservation of ecosystems.

1 Valérie Laforest and Natacha Gondran carry out their research in the framework of the Environment, City and Society Laboratory, a joint CNRS research unit composed of 7 members including Mines Saint-Étienne.

Antonin Counillon

This article is part of a 2-part mini-series on the circular economy.
Read more:

Waste management: decentralizing for better management

Circular economy, environmental assessment and environmental budgeting

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To implement a robust and durable circular economy strategy, it is important to assess its environmental impacts. Valérie Laforest and Natacha Gondran, both researchers at Mines Saint-Étienne, explain the reasons for incorporating an absolute environmental sustainability assessment method and the underlying concept of “environmental budgeting“.

The lifestyles of our contemporary societies are exerting constant and unsustainable pressure on the balance of our planet. One of the proposed strategies for protecting the Earth’s resources is the circular economy. The concept may seem simple – to encourage recycling and reuse to limit the consumption of raw materials – but environmental impact assessment involves a large number of variables and makes things complicated. This is why researchers are working to design more effective assessment methods for these impacts than the current tools, which are still insufficient. In particular, they are developing a systemic approach that integrates absolute environmental impact assessment.

This issue is at the heart of Valérie Laforest and Natacha Gondran’s work, both researchers at Mines Saint-Étienne1 and members of the Environmental Assessment of Waste, Effluents, Materials, Sediments and Soils (EDEEMS) Scientific Interest Group (SIG). Bringing together seven regional institutions, the EDEEMS SIG carries out, among other things, research on the health and environmental impacts of the circular economy. “The aim is to show that our collaborations can offer the economic world scientific support to overcome the obstacles that still pose a problem”, says Valérie Laforest. The researcher is a specialist in environmental assessment and focusses on the evaluation methods for these impacts. At the heart of the issue, it is important to define the indicators to assess pressure on natural resources and environments caused by humans.

A systemic approach

“This can be very experimental,” says Valérie Laforest. Within the SIG, “we’re starting out on a laboratory scale, then we’ll progressively move up to a pilot level to demonstrate the validity of our work on an industrial scale”. Let us consider the building sector and its impact on ecosystems as an example. Analyses and monitoring are done through ecotoxicology studies or environmental impact assessments from the source of pollutant emissions to their final destination. At the same time, the different transfers constituting all possible interactions between the source and the target, such as groundwater or soils, are also studied.

In the context of the circular economy, evaluating the “source” elements of pollution requires meticulous characterization of the materials produced from recycling. For example, besides the composition of the recycled materials itself, their reactivity must also be studied, with biodegradation tests for sources of organic pollution. These indicators are essential for assessing the different types of pressure on the ecosystems in greater detail.

“There is a growing interest in research into the planet’s limits today. The idea is to compare this work with the impacts generated by production systems using what are known as absolute environmental sustainability assessment methods,” says Valérie Laforest. The Earth not only has a limited amount of resources, but also a limited capacity for absorption. We must therefore take account of all the impacts, both positive and negative, across all sectors. The researcher adds that in order to implement a sustainable circular economy, it is necessary to have “robust and transparent methods that allow us to act with knowledge of the consequences and perfect control of the risks.”

Environmental budgeting

“It is essential to integrate a systemic approach to standardize indicators for the evaluation of environmental impacts,” says Valérie Laforest. And, ultimately, to understand the impact of anthropogenic activities in relation to our planet’s capacity to absorb them. To avoid exceeding this capacity, one idea is to put in place an “environmental budget”. “We are aiming to break down the planet’s absorption capacity by type of activity according to the needs and contribution of each one”, explains Valérie Laforest. “Imagine allocating to each sector of activity a level of emissions that can be absorbed by the planet without too much disruption to the natural balance.”

However, distributing the planet’s total budget across the different activities of society raises various scientific, ethical and political questions. In addition, the total environmental budget for a given sector would have to be able to be broken down between the different brands or companies to see what they consume out of the available budget. “As part of a PhD by Anastasia Wolff, we adapted existing models and tested these methods for the food industry branch of a major retail group. For some indicators, such as climate change, they had already exceeded the allocated budget. Just for eating, this brand and its clients were already exceeding the environmental budget available to them,” explains Natacha Gondran.

Valérie Laforest and Natacha Gondran’s team focuses its work on the choice of relevant indicators, the definition and allocation of this ecological budget to a sector of activity and the evaluation of a given sector’s consumption of and contribution to this budget. It is a mammoth task. This global approach also aims to raise awareness of the scope of the issues in order to target which points to work on to efficiently reduce the environmental impact.

Besides this, there are other essential dimensions for implementing a sustainable circular economy. “The participation and involvement of local actors in the process is essential. It is a key factor of success”, says Valérie Laforest. While the researchers are developing the right tools, it is still vital to work with local actors to understand the situation and implement the process. “At IMT, the circular economy is one of the priority actions on the theme of renewable energy and resources. In addition, IMT is at the heart of numerous projects within its different schools. IMT also supports platforms such as the Plateforme Territoire at Mines Saint-Étienne, which aims in particular to help local actors visualize information through a spatial representation and target priority issues,” says Valérie Laforest.

1 Valérie Laforest and Natacha Gondran carry out their research in the framework of the Environment, City and Society laboratory, a joint CNRS research unit composed of 7 members including Mines Saint-Étienne.

Tiphaine Claveau

brominated plastics

Innovative approaches to recycling brominated plastics

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Recovering untreated plastic materials and putting them back into the recycling loop through a decontamination line is the challenge of thesis research by Layla Gripon, a PhD student at IMT Lille Douai. These extraction methods contribute to a comprehensive approach to recovering plastic materials, in particular brominated plastics.

High consumption of electronic devices implies a significant amount of waste to be processed. While waste electrical and electronic equipment (WEEE) is often seen as a gold mine of silver and rare earths, plastic materials represent 18% of these deposits. This was equivalent to 143,000 tons in France in 2018 according to a report by Ademe (Ecological Transition Agency) published in 2019. But not all this plastic material is created equal. Some of it contains atoms of bromine – a chemical compound that is widely used in industrial flame retardants. These substances meet requirements for reducing flammability hazards in devices that may get hot while in use, such as computers or televisions. There’s just one problem: many of these substances are persistent organic pollutants (called POP). This means that they are molecules that can travel great distances without being transformed, and which are toxic to the environment and our health. The amount of these molecules contained in devices is therefore regulated in the design stage, as well as in the end-of-life processing stage. In 2019, the European Union set the threshold at which waste containing bromine can no longer be recycled at 2 grams per kilo. Beyond this limit, it is destroyed through incineration or used as fuel. But couldn’t it still be recycled, with the right processing? For her thesis co-supervised by researchers at IMT Lille Douai and The Alençon Institute of Plastics and Composites (ISPA), Layla Gripon has set out to identify a method for separating brominated flame retardants from plastics. “We seek to maximize recycling by limiting the loss of unrecoverable material, while complying with regulations,” says the PhD student.

Finding the right balance between extraction efficiency and respect for the environment

Approximately 13% of WEEE plastics are above the legal threshold for brominated flame retardants, which is equivalent to 17,500 tons in France. Samples tested in the laboratory reached a concentration of bromine up to 4 times higher than the legal threshold. In order to process them, Layla Gripon tested a number of methods that do not degrade the original plastic material. The first was highly efficient, removing 80% of the bromine. It was an extraction method used diethyl ether, an organic solvent. But since it uses a lot of solvent, it is not an environmentally-friendly solution. Another technique based on solvents is dissolution-precipitation. Through this technique, plastic is dissolved in the solvent, which retains the flame retardants. “In order to limit the environmental impact of this process, we subcontracted the German Fraunhofer Institute to carry out a test. Their patented process (CreaSolv) allows them to reuse the solvents. In the end, the bromine was no longer detected after processing and the environmental impact was reduced,” she explains.

In addition, a method that is more environmentally-friendly – but less efficient, for now – uses supercritical CO2, a green, non-toxic and non-flammable solvent. This process is already used in the agri-food industry, for example, to remove caffeine from coffee. In the supercritical state, carbon dioxide exists in an intermediate state between liquid and gas. To achieve this, the gas is heated and pressurized. In practice, the closed-loop system used by Layla Gripon is simple. Shredded plastic is placed inside an autoclave in which the supercritical fluid circulates continuously. When it leaves the autoclave, the recovered gas brings various additives with it, including a portion of the flame retardants.

To improve the yield of the second method, Layla Gripon planned to use a small amount of solvent. “The tests with ethanol improved the yield, with a rate of 44% of bromine removed, but this wasn’t enough,” says the PhD student. Other solvents could be considered in the future. “The supercritical CO2 method, on the other hand, works very well on the brominated flame retardant that is currently the most widely-used in industry (tetrabromobisphenol A – TBBPA),” she adds. But the most difficult brominated plastics to process are the ones that have been prohibited for a number of years. Although they are no longer available on the market, they are still accumulating as waste.

A large-scale approach to recovering recycled plastic  

These promising processing techniques must still evolve to respond fully to the needs of the recycling industry. “If these two processes are selected for applications beyond the laboratory, their environmental impact will have to be minimized,” says the PhD student. Such methods could therefore be incorporated in the pre-processing stage before the mechanical recycling of WEEE plastics.

At the same time, manufacturers are interested in the benefits of this research initiated through the Ecocirnov1 Chair. “They’ve joined this project because the laws are changing quickly and their products must take into account the need to recover materials,” explains Éric Lafranche, a researcher who specializes in plastic materials at IMT Lille Douai and is Layla Gripon’s thesis supervisor. The objective of maximizing recycling is combined with an ambition to create new products tailored to the properties of the recycled materials.  

Read more on I’MTech: A sorting algorithm to improve plastic recycling

“Recycling today is different than it was 10 years ago. Before, we sought to recover the material, reuse it with similar properties for an application identical to its original use. But the recycled product loses some of its properties. We have to find new applications to optimize its use,” says Éric Lafranche. For example, French industrial group Legrand, which specializes in electrical installations and information networks, seeks to use recycled plastic materials in its electrical protection products. In collaboration with researchers from IMT Lille Douai, the company has implemented a multilayer injection system based on recovered materials and higher-grade raw materials on the surface. This offers new opportunities for applications for recycled plastics – as long as their end-of-life processing is optimized.

By Anaïs Culot.

1 Circular economy and recycling chair created in 2015, bringing together IMT Lille Douai, and the Alençon Institute of Plastics and Composites and Armines.