The constant growth in global consumption has led to a significant increase in the amount of waste produced. However, there are innovative solutions for harnessing this abundance of waste into a valuable source of energy. Waste-to-energy, i.e. the use of waste that has not been recycled or recovered in material form to generate energy, offers a promising prospect for meeting certain energy and environmental challenges.
There are two main approaches to waste-to-energy conversion: thermal treatment and biogas recovery. Thermal treatment includes methods such as incineration, pyrolysis, gasification and co-incineration. Incineration with energy recovery is commonly used, where the heat generated by waste combustion is transformed into pressurized steam, then expanded in an alternator to produce electricity. In France, a network of 127 household waste incineration plants is in operation, but requires constant monitoring to avoid any risks associated with emissions and process residues. Pyrolysis and gasification, on the other hand, involve heating waste in the absence of oxygen, enabling the substances generated to be transformed into fuel, electricity and heat.
Biogas recovery is another important method. It involves the methanization of organic waste by fermentation, transforming it into biogas, a renewable energy source.This approach is crucial for reducing greenhouse gas emissions and recovering the energy contained in organic waste.
Faced with the growing problem of landfilling waste, a new sector is emerging: Solid Recovered Fuels (filière CSR in french). Composed mainly of non-hazardous waste residues that cannot be fully recycled, such as wood, paper and certain plastics, Solid Recovered Fuels are transformed into powdered fuel for industrial use.This approach helps to recover non-recyclable waste and reduce its environmental impact.c
The regulatory framework also plays a crucial role in promoting waste-to-energy conversion. France’s Energy Transition Law calls for a 50% reduction in the amount of waste sent to landfill by 2025, while the AGEC law (Anti-Gaspillage pour une Économie Circulaire) requires the energy recovery of at least 70% of waste that cannot be recovered in material form.
An inspiring example of this approach is the “Plastic Odyssey” ship project, which proposes an innovative vision for the recycling of plastic waste. The project aims to transform the 26,000 tonnes of plastic waste dumped daily into the oceans into a potential source of energy.Using simple, low-cost technologies, the project team has designed a laboratory vessel equipped with low-tech machinery to transform plastic into fuel, pipes, tiles and bricks.This initiative, starting in Marseille and extending to Egypt and Latin America, for example, illustrates the importance of innovative, reproducible solutions to waste-related problems.