Abstract
Volatile fatty acids (VFAs) are versatile intermediates for circular chemical and fuel manufacturing. Current VFA production relies heavily on fossil feedstocks and serves a narrow set of commodity markets. Here, we project VFA demand through 2050 and evaluate the potential to recover VFAs from abundant, widely available waste streams, exploring how waste-derived VFAs can support a broader circular carbon economy by midcentury. We project that the global VFA recovery potential from waste could reach ∼581 Mt yr(-1) by 2050, roughly 10 times higher than projected demand in existing markets. Integrating waste-carbon streams with anaerobic digestion infrastructure and emerging VFA production and separation technologies provides a feasible route for large-scale waste-to-VFA conversion. We project that in a 2050 circular scenario, ∼581 Mt yr(-1) of waste-derived VFAs can be flexibly distributed across various chemicals and energy sectors, supplying a significant portion of anticipated demand and establishing VFAs as a scalable, multifunctional platform molecule for a circular carbon economy.