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What do we know about the environmental impact of biocomposites?

Bio-based materials are an alternative to those derived from fossil resources. They have been increasingly promoted in recent years. However, given the recent development of this sector, their real environmental impact is still relatively unknown. Joana Beigbeder, researcher in environmental analysis at IMT Mines Alès, provides an update on the life cycle analysis (LCA) of these emerging materials.

Although bio-based materials are presented as an effective alternative to their petroleum-based predecessors, the details of their environmental impact are still not well known. Plant-based materials are certainly an improvement for some impacts, such as carbon footprint, but it can be trickier when it comes to soil use or soil pollution, for example. To get to the bottom of this, life cycle analysis is an indispensable tool.

Joana Beigbeder, researcher in environmental impacts at IMT Mines Alès, is working on the life cycle analysis of these new bio-based materials, particularly biocomposites. The objective is to compare the environmental impact of different scenarios, either between bio-based and petroleum-based materials, or according to the different stages of the life cycle of the same material. The researcher says, “the focus of life cycle analysis is to study several environmental impacts in parallel and to identify possible transfers of pollution throughout the life cycle of a product”.

Different sources of impact

With regard to environmental impact, some points seem obvious. If we only look at carbon footprint, it seems obvious that bio-based materials are more beneficial than their petroleum-based cousins. But the reality is more complex because there are many variables to consider. “Carbon impact is a well-known indicator, but we must also take into account the different impacts of pollution, human toxicity, soil or water pollution or global warming”, says Joana Beigbeder. Take the automotive sector, for example. If for the same function, a part made of bio-based material has a higher weight, it will require more energy to use and will not necessarily be beneficial. “It may be a better solution from an environmental point of view, but that’s precisely what the LCA will tell us,” she says.

Some points seem more obvious, such as the consumption of fossil resources and the impact on global warming in general. Plant materials absorb CO2 during their growth, which gives them an undeniable advantage. That said, their growth implies an agricultural impact, especially on land use. “Depending on the type of crop, this can lead to soil pollution. Generally, the more fertilizers and additives that are required for growth, the less beneficial some of the impacts will be,” says Joana Beigbeder. This brings up a new issue that does not exist with petroleum-based materials.

“It’s always a case of compromising, and we look for ways to improve the process or the product,” says the researcher. “Plants, such as flax or hemp, require little or no input and are therefore a preferred option. But the material is only one area for improvement when it comes to eco-design”, she notes. To reduce the environmental impact of a product, lightening its weight and extending its lifespan are key points. This can include the reparability of the product, or even new concepts such as prioritizing the use of the product over the purchase of the product.

“There is also a question of ecological common sense, if we study a disposable product, reusable or compostable materials will be favored,” says Joana Beigbeder. One research topic includes the development of compostable diapers and band-aids, a promising step in reducing plastic pollution.

Predicting potential impacts

“Life cycle analysis study is really done on a case-by-case basis depending on the service provided by a product,” says Joana Beigbeder. To estimate the consumption of solvents or the chemical synthesis of materials, the researcher uses previous scientific publications and mathematical models. But in some areas, data is missing. “We sometimes have to use fairly strong approximations on certain impacts, but this still allows us to map trends and areas for improvement,” she maintains. This can be the case for the production of plant fibers, as well as for their disposal at the end of their use.

As these materials do not yet have a major presence on the market, there are currently no channels for processing the resulting waste. In fact, there is no data on the environmental impact of the incineration, landfill, or pollution from these newly emerging materials. “To estimate these impacts, we assimilate them to other, better-known closely-related materials on which we have data, to develop our hypotheses,” she explains. This work also generates new data for LCA such as recycling simulations for end-of-life treatment.

“Some bio-based materials are at the laboratory stage today, and it’s still hard to imagine what will happen at the industrial stage,” says Joana Beigbeder. The researcher then works on predictions: she imagines scenarios for materials that are not yet on the market and analyzes whether this has any impact on an environmental level. Also, given the recent nature of the bio-materials sector, their production will be less optimized than that of traditional petroleum-based materials which have evolved and improved. “This works against the newer materials, as they will need to go through several developmental stages,” she points out.

This research is essential for the development of sustainable alternatives to conventional materials and is part of an overall vision to meet the challenges of plastic pollution. “A lot of research is focused on the development of new materials with a smaller environmental impact. The VOICE project, for example, launched in 2018 in partnership with Innovation Plasturgie Composites, Silvadec, IMT Mines Alès and funded by ADEME, focuses on the recycling of biocomposite decking. Or the Agrobranche project, which brings together 8 French partners[1], and focuses on, among other things, the study of bio-based reinforcements from agroforestry,” she concludes. These two projects reflect the blossoming of new emerging materials and the current development of research to find sustainable alternatives to the plastic problem.

[1] Scop Agroof (coordinator), IMT Mines Alès, CIRAD BiowooEB, LERMAB, FRD, CRA Bretagne, CIRAD AMAP, INRA SPO

Tiphaine Claveau

LCA

What is life cycle analysis?

Life cycle analysis (LCA) is increasingly common, in particular for eco-design or to obtain a label. It is used to assess the environmental footprint of a product or service by taking into account as many sources as possible. In the following interview, Miguel Lopez-Ferber, a researcher in environmental assessment at IMT Mines Alès, offers insights about the benefits and complexity of this tool.

What is life cycle analysis?

Miguel Lopez-Ferber: Life cycle analysis is a tool for considering all the impacts of a product or service over the course of its life, from design to dismantling of assemblies, and possibly recycling – we also refer to this as “cradle to grave.” It’s a multi-criteria approach that is as comprehensive as possible, taking into account a wide range of environmental impacts. This tool is crucial for analyzing performance and optimizing the design of goods and services.

Are there standards?

MLF: Yes, there are European regulations and today there are standards, in particular ISO standards 14040 and 14044. The first sets out the principles and framework of the LCA. It clearly presents the four phases of a LCA study: determining the objectives and scope of the study; the inventory phase; assessing the impact, and the interpretation phase. The ISO 14044 standard specifies the requirements and guidelines.

What is LCA used for?

MLF: The main benefit is that it allows us to compare different technologies or methods to guide decision-making. It’s a tremendous tool for companies looking to improve their products or services. For example, the LCA will immediately pinpoint the components of a product with the biggest impact. Possible substitutes for this component may then be explored, while studying the impacts these changes could lead to. And the same goes for services. Another advantage of the “life cycle” view is that it takes impact transfer into account. For example, in order to lower the impact of an oven’s power consumption, we can improve its insulation. But that will require more raw material and increase the impact of production. The LCA allows us to take these aspects into account and compare the entire lifetime of a product. The LCA is a very powerful tool for quickly detecting these impact transfers.

How is this analysis carried out?

MLF: The ISO 14040 and 14044 standards clearly set out the procedure. Once the framework of the study and objectives have been identified, the inflows and outflows associated with the product or service must be determined – this is the inventory phase. These flows must be brought back to flows from the environment. To do so, there are growing databases, with varying degrees of ease of access, containing general or specialized information. Some focus on agricultural products and their derivatives, others on plastics or electricity production. This information about flows is collected, assembled and related to the flow for a functional unit (FU) that makes it possible to make comparisons. There is also accounting software to help compile the impacts of various stages of a product or service.  

The LCA does not directly analyze the product, but its function, and it is able to compare very different technology. So we will define a FU that focuses on the service provided. Take two shoe designs, for example. Design A is of very high quality so it requires more material to be produced, but lasts twice as long as Design B. Design A may have greater production impacts, but it will be equivalent to two Design Bs over time. For the same service provided, Design A could ultimately have a lower impact.

What aspects are taken into account in the LCA?

MLF: The benefit of life cycle analysis is that it has a broad scope, and therefore takes a wide range of factors into account. This includes direct as well as indirect impacts, consumption of resources such as raw material extraction, carbon footprint, and pollution released. So there is a temporal aspect, since the entire lifetime of a good or service must be studied, a geographical aspect, since several sites are taken into consideration, and the multi-criteria aspect, meaning all the environmental compartments. 

Who conducts the LCA?

MLF: When they are able to, and have the expertise to do so, companies have them done in-house. This is increasingly common. Otherwise, they can hire a consulting firm to conduct them. In any case, if the goal is to share this information with the public, the findings must be made available so that they can be reviewed, verified and validated by outside experts.

What are the current limitations of the tool?

MLF: There is the question of territoriality. For example, power consumption will not have the same impact from one country to another. In the beginning, we used global averages for LCA. We now have continental, and even national averages, but not yet regional ones. The more specific the data, the more accurate the LCA will be.  

Read more on I’MTech: The many layers of our environmental impact

Another problem is additional or further impacts. We operate under the assumption that impacts are cumulative and linear, meaning that manufacturing two pens doubles the impacts of a single pen. But this isn’t always the case. Imagine if a factory releases a certain amount of pollutants – this may be sustainable if it is alone, but not if three other companies are also doing so. After a certain level, the environmental impact may increase.  

And we’re obviously limited by our scientific knowledge. Environmental and climate impacts are complex and the data changes in response to scientific advances. We’re also starting to take social aspects into consideration, which is extremely complex but very interesting.

By Tiphaine Claveau