Néolithe fossilises our waste

There is no shortage of innovation in recycling, in the context of waste reduction. The industrial start-up Néolithe is not to be outdone: it has come up with the idea of fossilising non-recyclable waste and transforming it into aggregate.

The story began with a conversation between a father and son. "My father is a former stonemason. His speciality was the white limestone used to build the Châteaux of the Loire Valley. One day, he realised that this material came from the sedimentation of Cretaceous waste. So he wondered whether we could transpose this fossilisation process to our own waste. He suggested I work on it, and that's how our start-up was born," recalls Nicolas Cruaud, co-founder of Néolithe. A trio made up of William Cruaud, his son Nicolas Cruaud, who trained at the École Polytechnique, and Clément Bénassy, a graduate of AgroParisTech, set out on this adventure in January 2019. 

A process that turns our waste into building materials

Through this project, the three founders aim to prevent the incineration and landfilling of our end waste, processes which are particularly harmful in ecological terms (greenhouse gas emissions or GHG). To achieve this, Néolithe installs "fossilisers" in sorting centres, which recover mixed non-recyclable waste such as gypsum, plastics, wood, insulation agents etc., known as "sorting rejects". As Nicolas Cruaud explains, "After sorting, three quarters of what is in waste containers is included in our processes. This mixed waste is shredded very finely, to below 500 microns (µm). The result is a ‘waste shred’ that we react with our binder. It has a mineralising effect, resulting in a mineral paste which is then pressed very hard, with no heating." At the end of the chain, aggregates of the desired shape and density are produced, which can be substituted for the natural aggregates used in construction, and in concrete in particular. The material has been dubbed "anthropocite" by the start-up. 

The process is mainly mechanical - it requires no heating and emits no waste (odours, smoke, waste water, etc.) - with the exception of binder production, the keystone of this accelerated fossilisation process. "Our binder is subject to industrial secrecy. What I can tell you is that we use low-heat mineral bases and industrial co-products to produce it. We buy the various components and formulate them on site," adds the co-founder. 

Trapping CO₂

According to the French government website, "the building sector [...] generates 23% of France's GHG emissions". To limit these emissions, the government is legislating and forcing manufacturers to decarbonise their activities, and therefore their materials. A boon for Néolithe. "Not only does our process help reduce landfill and the incineration of our waste, but the accelerated fossilisation of waste also traps CO₂. For every ton of aggregate produced, 337 kg of CO₂ equivalent is stored. As a result, our aggregates have a negative carbon footprint, and the more you put into concrete, the more you decarbonise it. It's very useful for building professionals, especially in the current context," says Nicolas Cruaud. Another advantage is that the aggregates produced by the start-up can be reused when concrete reaches the end of its life. It is re-crushed and reintegrated into various different materials. 

But by fossilising all our waste, is there a risk of pollution if water runs off the material? "There are certain thresholds we have to respect. We carry out leaching tests to simulate erosion. Water is poured over our anthropocite to analyse the release of toxic substances. We've done a lot of work on this, and our studies have shown that our material is safe, and that there are no specific pollutants," explains Nicolas Cruaud. 

Several plants in 2023

The 180 employees of the company, soon to be based in Beaulieu-sur-Layon (Maine-et-Loire), have a full schedule for 2023. Néolithe is now deploying its fossilisers, which cover a floor area of around 500 m², at customer sites. "Our industrial site is divided up into two parts. The first is used for the assembly of our waste processing machines. These machines are leased out to customers, who feed them with their waste. We then resell the aggregates," explains the co-founder. For the beneficiary, the advantage is twofold: he pays less for the rental of the machines, which fossilise 10,000 tonnes of waste a year, than for landfill, while reducing his environmental impact. "The second part enables us to produce our binders," continues Nicolas Cruaud. "The facility is still under construction, but will be up and running this summer."

This year, three corporate customers will benefit from Néolithe's services. The first is a carrier, called Courant, which also operates a sorting centre in the Angers area. 
"By early 2024, our fossilisers will be working. Once we have the capacity to process all the French waste emitted each year, we'll be able to reduce the country's carbon footprint by 7% and thus become, like hydrogen today, a major lever for decarbonisation," hopes Nicolas Cruaud. 

By 2026, Néolithe aims to have a processing capacity of 2.5 million tons of waste, implying savings of 1 million tons of CO2 per year. The start-up also plans to expand internationally at a later date. Steps have already been taken to install fossilisers outside France, in England, the Nordic countries, Switzerland and Japan. 

Numerous fund-raising initiatives

Even before it was set up, Néolithe had already attracted a great deal of support. "When Clément Benassy and I were still students, we won a competition organised by Université Paris-Saclay. We had studied a number of projects together, because the University puts up a lot of new buildings and therefore needs a lot of materials, which also produces waste. In fact, we had hoped to use it for one of our pilot projects, but in the end the space available was too small," he explains. In its early days, Néolithe was hosted by the École Polytechnique's X Up incubator. One year after its creation, the start-up launched its first fund-raising round, raising €500,000. It is also supported by the French Environment and Energy Management Agency (Ademe), which contributed €375,000. Fund-raising continues at the rate of one a year. In 2021, Néolithe raised €2.5 million, and in 2022, €22 million. This almost quarter-billion euros is being used to build the Beaulieu-sur-Layon site and recruit almost 120 new employees. According to Nicolas Cruaud, "We'll be raising funds until 2025 or 2026, until we're profitable. The roll-out of our customer sites in 2024 will enable us to gradually generate sales."