SUEZ and PYREG have announced the deployment of Pyrolis® S2B, an integrated pyrocarbonisation solution designed to convert municipal and industrial sewage sludge into biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More. This partnership combines SUEZ’s expertise in thermal sludge treatment with PYREG’s specialized pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More technology. The system is designed to address the environmental challenges posed by the 340 million tonnes of industrial and agricultural effluents generated annually in France. By integrating drying and carbonization into a single modular unit, the technology facilitates the transition from waste management to resource recovery within a circular economy framework.

A primary challenge addressed by this technology is the management of contaminated waste streams, specifically the presence of per- and polyfluoroalkyl substances (PFAS), microplastics, and pharmaceutical residues in sewage sludge. Traditional disposal methods often fail to eliminate these persistent “forever chemicals,” which can leach into soil and water systems. Furthermore, dewatered sludge typically requires significant energy to process and occupies substantial volume. The Pyrolis® S2B system must therefore achieve high-temperature destruction of pollutants while maintaining an energy-efficient footprint that remains viable for municipal and industrial operators.

The solution utilizes a multi-stage, autothermal process that begins with a low-energy drying technology developed by SUEZ, bringing sludge to a 90% dry solids content. This dried material enters the PYREG reactor for pyrolysis at approximately 600 °C in a low-oxygen environment, producing stable biochar and a hydrocarbon-rich gas. To optimize efficiency, this gas is oxidized at temperatures exceeding 950 °C, generating the thermal energy required to sustain both the drying and pyrolysis stages. This high-temperature oxidation serves a dual purpose: it ensures the plant is energy-self-sufficient and effectively destroys PFAS and other hazardous organic contaminants.

The outcomes of this deployment include a 90% reduction in waste volume and the production of a contaminant-free, phosphorus-rich biochar. The resulting material is recognized by the IPCC as an effective tool for long-term carbon sequestration, qualifying it for participation in carbon credit markets. Beyond sequestration, the biochar serves as a high-value soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More that improves water retention and nutrient efficiency in agriculture. Additionally, it offers a sustainable additive for the construction industry to lower the carbon footprint of concrete and asphalt, demonstrating a scalable model for turning challenging waste into a stable, carbon-negative resource.