Composting gains popularity

Composting is a waste treatment process that is currently gaining popularity. Drawing from its extensive experience in the field, Irstea aims to make the composting sector more sustainable and ensure it is an integral part of any waste management approach based on a circular economy. Within this context, the pre-fermentation terminal developed by Emeraude I.D. in partnership with Irstea was presented to the Pollutec Exhibition in Lyon at the end of November 2018.


Composting is a process in which organic matter is broken down by microorganisms, resulting in compost, a material rich in fertile components that can be reused as fertilizer without harming the environment. Initially applied to agricultural waste, the method is also used to treat household and other similar waste (organic household waste, sewage sludge, green waste) and food processing waste. Its advantages include its ease of implementation, its lower cost compared to other processes, and the quality of its end product (stable, free from pathogens, consistent, etc.)

For several years, regulations have encouraged separate treatment for organic waste, particularly using composting. For example, the Grenelle 2 law (July 2012) requires that large producers (over 10 tons/year) sort their biowaste, and more recently, the Law on Energy Transition for Green Growth (August 2015) provides for general biowaste sorting at the source for households and companies by 2025.

>Now well known, the biological processes and heat transfers in composting have been optimized to improve the quality of the resulting compost. For composting to remain sustainable, new challenges must be met, including the development of composting on a local scale. Irstea researchers have already started looking into these issues.

Promoting local composting

To support public authorities and local governments in managing biowaste, Irstea has several projects focusing on local composting. The results of these projects have included a guide for local authorities suggesting methods to promote composting (Eccoval) and a tool (Miniwaste) to help them improve management planning for biowaste, encourage regionally adapted solutions, and assess their efficiency.

In light of the current requirement for biowaste to be sorted at source by 2025, local recovery solutions are more relevant than ever. In addition to rolling out domestic composting and implementing separate collections, a new option is currently being explored as part of the European Decisive project (2016-2020): micro-scale anaerobic digestion.

Led by Irstea, this project is based on studies looking at composting and aims to perfect technical solutions for micro-scale anaerobic digestion to provide local waste management that is adapted to urban areas and integrated into a circular economy. The ultimate aim is to create localized waste treatment plants with limited environmental impact and which promote the production of new resources (compost, biogas, anaerobic digestate) that can be recovered immediately.

Local facilities “made in Irstea”

Following its design of the first prototype composter for collective housing, Irstea has designed a customizable community composter in partnership with the association Emeraude Création. This composter can be adapted to the needs of users in both rural and urban areas. In 2012, this multi-compartment composter was awarded the innovation prize at the Durabili-Ty competition and is now used by small food & beverage establishments.

pre-fermentation unit
Eco-Station pre-fermentation unit at the Pollutec 2018 exhibition
© Emeraude Création

During the Pollutec exhibition, which ran from November 27 to 30, 2018 in Lyon, Emeraude Créationpresented the latest innovation resulting from their partnership with Irstea: the Eco-Station pre-fermentation unit. Used for the first stage in waste degradation, the unit was specifically designed to recover kitchen waste (central kitchens, schools, hospitals, retirement homes). As a result of its innovative design, it provides a reduction of around 60% in waste volumes, a natural increase in temperature due to its optimum insulation, and easier mixing of waste. The unit is equipped with a system to control the degradation of waste that is unique both before and after the waste treatment chain, ensuring the process occurs successfully. The aim is to reduce the volume of waste without unpleasant odors and create a stable compost. Following its success at the Pollutec exhibition, Emeraude Création will start production of the unit in Spring 2019 with the aim of installing around 20 units during the year in partnership with local authorities, to test various measures and improve the unit through feedback.

Irstea drives innovation

Irstea protects its research results and is working to transfer them to socioeconomic stakeholders. The process of transferring results makes it possible to create new value based on innovation by meeting the needs of companies to boost their activity, support their competitiveness, and help them win new markets through the use of evolving technologies.

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