As urban populations increase, urban waste management is becoming a crucial issue for regional stakeholders. Through the European Decisive project, Irstea and its partners are drawing up an innovative management approach based on local recovery and set within a circular economy context. Three years on from the launch of Decisive, the first demonstration site near Lyon will be inaugurated and introduced to the public on November 14. This is an opportunity to review the progress of this promising project with Anne Trémier, project coordinator and Irstea research engineer.
Receiving 7.7 million euros of funding, the Decisive project was picked as part of a call for projects by the European H2020 program , which aims to discover innovative urban waste management solutions. How is the Decisive proposal innovative compared to existing solutions?
To ensure the success of this concept, the Decisive partners are focusing on small or micro-scale anaerobic digestion. What will this method look like?
Anne Trémier: As with the traditional anaerobic digestion process, the “miniature” method will produce biogas, which can be reused directly as energy, and digestate (anaerobic digestion residue), which can be used to create a high value-added product such as biopesticides. To ensure the process is compatible with a dense urban environment, we expect to create facilities that will be able to process a maximum of 200 tons of biowaste per year , which is equivalent to the amount of waste produced by a neighborhood of 800 to 1000 households. Our main technological challenge is how to implement an anaerobic digestion process that is adapted to this scale, has low power requirements so that its energy balance remains positive, but which is also simple to use, compact yet reliable to meet local requirements (safety, regulations).
Another notable development is the installation of a micro-scale anaerobic digester (based on existing commercial technologies) in real conditions, at the Ecully horticultural school near Lyon. Fed by the school cafeteria and nearby hotels and restaurants in Lyon, this demonstrator was launched in October to establish the feasibility of local management for the whole sector. In other words, it will close the loop, transforming biowaste into energy and fertilizers that can be used directly on site to grow vegetables.
Aside from the organizational issues, what is that status of the planned micro-scale anaerobic digester process?
What do you think is the greatest obstacle that needs to be overcome before your proposed waste management method becomes a reality?
Decisive project profile
Decisive presented at the European Workshop on Bioeconomy
To identify the research needed to create a sustainable bioeconomy that incorporates the finite limitations of the planet, INRA, Irstea and IFPEN, in partnership with the French Ministries of Agriculture and Food, Higher Education, Research and Innovation, and Ecological and Solidarity Transition and the German Federal Ministry of Food and Agriculture are organizing a European workshop on bioeconomy on October 29 and 30, 2019 in Paris. During this event, Anne Trémier will discuss the initial results and future aims of the Decisive project as part of the “circular urban bioeconomy” theme.
- Article. The Conversation (by A. Trémier): Micro-scale anaerobic digesters: a solution to improving urban waste recovery?
- Special feature. Resourceful waste
- Article. Composting: an increasingly popular way of managing biowaste
- Consult the Decisive project website
- Consult the web page of the Optimization of Processes in Agriculture, Agri-food and the Environment (OPAALE) research unit and the Irstea Rennes Center
 In contrast, existing small agricultural anaerobic digestion facilities process between 1000 and 2000 tons of organic waste per year.
 The method involves growing the Bacillus thuringiensis microorganism, known for its insecticide properties, on the anaerobic digestate.