Abstract
AbstractSince the dawn of agitated brewing in the Paleolithic era, effective mixing has enabled efficient reactions. Emerging catalytic chemical polyolefin recycling processes present unique challenges, considering that the polymer melt has a viscosity three orders of magnitude higher than that of honey. The lack of protocols to achieve effective mixing may have resulted in suboptimal catalyst effectiveness. In this study, we have tackled the hydrogenolysis of commercial-grade high-density polyethylene and polypropylene to show how different stirring strategies can create differences of up to 85% and 40% in catalyst effectiveness and selectivity, respectively. The reaction develops near the H2–melt interface, with the extension of the interface and access to catalyst particles the main performance drivers. Leveraging computational fluid dynamics simulations, we have identified a power number of 15,000–40,000 to maximize the catalyst effectiveness factor and optimize stirring parameters. This temperature- and pressure-independent model holds across a viscosity range of 1–1,000 Pa s. Temperature gradients may quickly become relevant for reactor scale-up.
Funder
Eidgenössische Technische Hochschule Zürich
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Publisher
Springer Science and Business Media LLC
Reference58 articles.
1. Hayden, B., Canuel, N. & Shanse, J. What was brewing in the Natufian? An archaeological assessment of brewing technology in the Epipaleolithic. J. Archaeol. Method Theory 20, 102–150 (2013).
2. Williams, F. J. Widnes and the early chemical industry 1847–71. A case of occupational mobility in the industrial revolution. Trans. Hist. Soc. Lancs. Ches. 134, 89–105 (1984).
3. Damköhler, G. Einflüsse der Strömung, Diffusion und des Wärmeüberganges auf die Leistung von Reaktionsöfen: I. Allgemeine Gesichtspunkte für die Übertragung eines chemischen Prozesses aus dem Kleinen ins Große. Z. Elektrochem. Angew. Phys. Chem. 42, 846–862 (1936).
4. Thiele, E. W. Relation between catalytic activity and size of particle. Ind. Eng. Chem. Res. 31, 916–921 (1939).
5. Pereira, C. J., Carberry, J. J. & Varma, A. Uniqueness criteria for first order catalytic reactions with external transport limitations. Chem. Eng. Sci. 34, 249–255 (1979).
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献
1. Stirring up success;Nature Chemical Engineering;2024-09-02