[Belle Histoire] COMPPIT: using AI to make the most of waste and biomass

" A joint laboratory is an ideal partnership for consolidating an existing collaboration," says Khaled Loubar, lecturer in the Department of Energy Systems and Environment (DSEE) at IMT Atlantique. " It enables joint research work to be carried out over the long term, following a shared roadmap, and cooperation to be supported by a dedicated structure and governance. These are the advantages that prompted S3d Ingénierie and the Génie des Procédés Environnement - Agroalimentaire (GEPEA - UMR CNRS 6144) laboratory, under the joint supervision of IMT Atlantique, to opt for this long-term partnership.

A relationship forged before the company was even created

S3d Ingénierie (Groupe Keran) is an engineering consultancy specializing in waste-to-energy and the production of alternative fuels. The company supports its customers - in particular local authorities and players in industry and agriculture - from the definition of needs to the design and implementation of solutions. " We don't offer an off-the-shelf product, because all requests are very different," explains Anthony Kerihuel, Managing Director of S3d Ingénierie. " So we prefer a tailor-made approach based on our expertise, which is enriched by each new experience. " For example, the company supported Cooperl Arc Atlantique, a major pork cooperative in Brittany, in the construction of a plant to produce biodiesel from animal fats.

S3d Ingénierie is interested in a wide range of thermochemical and biological processes to meet its customers' waste and biomass recovery needs. Some, such as combustion and methanization, are quite mature, while others, such as pyrolysis, pyrogasification, hydrothermal liquefaction and hydrothermal gasification, still need more feedback. That's why the design office relies on GEPEA's expertise, and has done so since its creation. Indeed, the company was co-founded in 2007, following the completion of Anthony Kerihuel's thesis at IMT Atlantique at the same time as that of... Khaled Loubar. Since then, the immediate link between the two entities has never been broken.

Innovative solutions for waste and biomass recovery

" Innovation plays a fundamental role in our business, given the complexity and uniqueness of the projects we undertake," says Anthony Kerihuel. " Our collaboration with GEPEA helps us stay at the cutting edge of new waste recovery technologies, thanks to the expertise of the research teams and the laboratory's resolutely modern equipment. " For example, GEPEA has the PREVER platform (Plateforme de Recherche et d'Étude sur la Valorisation Énergétique des Résidus), equipped with a wide variety of tools to help determine the best conversion process for the waste under consideration.

"From the laboratory's point of view, this historic collaboration provides us, of course, with essential support for our research work and the financing of our equipment, but not only that ", emphasizes Khaled Loubar. " Working with a key player like S3d Ingénierie helps us to keep abreast of the concrete needs of industry and local authorities, and to anchor our research in the realities of the field. " In this way, GEPEA uses feedback from the company to direct its work in line with trends, difficulties encountered in the recovery of certain wastes, or changes in the regulatory context.

For example, as part of a CIFRE thesis, the two partners are developing a process specific to sargassum - a particularly invasive seaweed, which proliferates notably on the coasts of the Caribbean Sea. Until now, there has been no optimal solution for recovering this considerable biomass. Researchers are working on a hydrothermal liquefaction process, and characterizing the resulting products.

Another thesis involved the study, testing and design of a small-scale biogas purification unit. The aim: to help farmers produce biomethane fuel that can be used to power their tractors with renewable natural biogas.

A joint laboratory to develop a more accurate prediction tool

Building on previous joint research projects, S3d Ingénierie and GEPEA have decided to give further impetus to their collaboration with the launch of the COMPPIT joint laboratory (Conception de modèles prédictifs des productibles issus de procédés de conversion thermochimique). Launched in April 2025, after being selected by the French National Research Agency (ANR), this project has been agreed for a period of 54 months. " But our idea is to make it last beyond the deadline set with the ANR," says Khaled Loubar.

COMPPIT's main objective is to develop a decision-making tool for selecting the most appropriate thermochemical conversion process for the waste or biomass to be recovered. And for each input-process pair, the solution will indicate the optimum operating conditions and deliver predictions as to productibles, their characteristics, as well as yield. " This information is crucial for organizations wishing to valorize their residues," emphasizes Khaled Loubar. " Indeed, how can you decide to invest in equipment without knowing the expected products or the necessary treatments to be applied after the process? "

Eventually, this solution will enhance S3d Ingénierie's support offering. "To tell the truth, we already have predictive tools," notes Anthony Kerihuel. " However, our current predictions could be made more accurate. The new tool developed as part of the joint laboratory will not only give us greater precision, but will also provide us with valuable additional information, such as the presence of pollutants within the productibles. It will be a real differentiating factor.

Experiments to help train AI

In order to deliver such results, the solution will rely on artificial intelligence, and more specifically on machine learning models. To this end, COMPPIT will benefit from the contribution of an IMT Atlantique teacher-researcher specialized in data science. However, as with any project based on AI, there is the question of the data available to train the models. " Some processes, such as pyrolysis or hydrothermal liquefaction, have been the subject of numerous theses, so we have enough data at our disposal," notes Khaled Loubar. " On the other hand, for others, such as hydrothermal gasification, the information available in the scientific literature will not be sufficient, and we'll have to generate our own data. "

While S3d Ingénierie will be able to supply some of these, the joint laboratory will also draw on its own experiments to feed its machine learning models. Work has already begun, with the launch of a thesis on pyrogasification. As for hydrothermal gasification, it is the subject of particular attention within the COMPPIT framework: the two partners wish to deepen their mastery of this process through the installation of dedicated pilot equipment at GEPEA. " This demonstrator will be used for tests on different types of waste and biomass," says Anthony Kerihuel. " And the results it delivers can be used to respond to our customers' problems, but also to feed our decision-support tool. "

Although the first research projects have already begun, COMPPIT is still in its start-up phase. As a result, the joint laboratory team is fine-tuning the final details, detailing its governance and roadmap. The next decisive step will be the recruitment of a research engineer, " the backbone providing the link and continuity between the work being carried out ", according to Khaled Loubar. In particular, his role will be to consolidate the results obtained in the experiments, which will be used to train the AI, an essential phase before the tool can be put to the test in real waste and biomass recovery situations.