CROtonic acid from Sewage Sludge

2026-07-22

Sludge produced in the EU by treatment of urban and industrial wastewater (WWTS) is 6 and 4 Mt/y on a dry basis. The organic matter contained in WWTS is enormous and the introduction of novel strategies that can valorise WWTS as feedstock for the synthesis of bio-based chemicals is a win-win approach in terms of circular economy and fossil resource exploitation. The CROSS-LIFE project will play a novel role in the “WWTS-to-chemicals” panorama by converting the C atoms in WWTS into a specific drop-in chemical (crotonic acid, CA) without consuming new resources, and simultaneously decreasing the volume of WWTS to manage at the End-of-Life. Crotonic acid, currently 100% fossil-based, finds application in coating, paint, textile, adhesives, ceramics, and agrochemical industries, with a global production of 60000 t/y and a selling price of 7-10 €/kg. Unigrà, a food company specialized in edible oils and fats, will participate in the project as an industrial WWTS supplier, while AqA, a company in the field of integrated water services, will be involved as a supplier of urban WWTS. Two DEMO plants (1000 t/y of WWTS) will be realized during the project at both companies‘ sites. Unigrà and AqA will benefit from a significant reduction of the volume of WWTS (about 70-80%) and will produce 1.5 t/y of bio-based crotonic acid with a carbon footprint of 4.8 kgCO2eq/kg CA (almost 3-times lower than the carbon footprint of fossil-based crotonic acid, 13.5 kgCO2eq/kg CA). A supplementary credit of 280 kgCO2/t dry WWTS will come from the avoided impacts of producing fossil-based crotonic acid, WWTS dewatering, and transporting a higher amount of WWTS to the final disposal site. Vinavil, one of the main Italian end-user of crotonic acid, will exploit bio-based crotonic acid to produce poly(vinyl acetate-co-crotonic acid) during (and after) the project. From a close to market perspective, Vinavil will benefit from the introduction of a novel bio-based monomer into its polymer portfolio

Italy

2025-12-15