Munyaneza, Nuwayo EricJi, RuiyangDiMarco, AdrianMiscall, JoelStanley, LisaRorrer, NicholasQiao, RuiLiu, Guoliang2024-12-052024-12-052024-11-18Munyaneza, N.E., Ji, R., DiMarco, A. et al. Chain-length-controllable upcycling of polyolefins to sulfate detergents. Nat Sustain (2024). https://doi.org/10.1038/s41893-024-01464-xhttps://hdl.handle.net/10919/123740Escalating global plastic pollution and the depletion of fossil-based resources underscore the urgent need for innovative end-of-life plastic management strategies in the context of a circular economy. Thermolysis is capable of upcycling end-of-life plastics to intermediate molecules suitable for downstream conversion to eventually high-value chemicals, but tuning the molar mass distribution of the products is challenging. Here we report a temperature-gradient thermolysis strategy for the conversion of polyethylene and polypropylene into hydrocarbons with tunable molar mass distributions. The whole thermolysis process is catalyst- and hydrogen-free. The thermolysis of polyethylene and polyethylene/polypropylene mixtures with tailored temperature gradients generated oil with an average chain length of ~C14. The oil featured a high concentration of synthetically useful α-olefins. Computational fluid dynamics simulations revealed that regulating the reactor wall temperature was the key to tuning the hydrocarbon distributions. Subsequent oxidation of the obtained α-olefins by sulfuric acid and neutralization by potassium hydroxide afforded sulfate detergents with excellent foaming behaviour and emulsifying capacity and low critical micelle concentration. Overall, this work provides a viable approach to producing value-added chemicals from end-of-life plastics, improving the circularity of the anthropogenic carbon cycle.application/pdfenPublic Domain (U.S.)Article - Refereedhttps://doi.org/10.1038/s41893-024-01464-x