Discovery of mixing characteristics for enhancing coiled reactor performance through a Bayesian optimisation-CFD approach

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 473; p. 145217
• Main Authors: Basha, Nausheen, Savage, Thomas, McDonough, Jonathan, del Rio Chanona, Ehecatl Antonio, Matar, Omar K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: Bayesian optimisation; Computational fluid dynamics; Mixing flow; Oscillatory flows; Bayesian optimisation; Computational fluid dynamics; Oscillatory flows; Mixing flow
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.145217

Plug flow characteristics are advantageous in various manufacturing processes for fine/bulk chemicals, pharmaceuticals, biofuels, and waste treatment as they contribute to maximising product yield. One such versatile flow chemistry platform is the coiled tube reactor subjected to oscillatory motion, producing excellent plug flow qualities equivalent to well-mixed tanks-in-series ‘N’. In this study, we discover the critical features of these flows that result in high plug flow performance using a data-driven approach. This is done by integrating Bayesian optimisation, a surrogate model approach, with Computational fluid dynamics that we treat as a black-box function to explore the parameter space of the operating conditions, oscillation amplitude and frequency, and net flow rate. Here, we correlate the flow characteristics as a function of the dimensionless Strouhal, oscillatory Dean, and Reynolds numbers to the reactor plug flow performance value ‘N’. Under conditions of optimal performance (specific examples are provided herein), the oscillatory flow is just sufficient to limit axial dispersion through flow reversal and redirection, and to promote Dean vortices. This automated, open-source, integrated method can be easily adapted to identify the flow characteristics that produce an optimised performance for other chemical reactors and processes. •Bayesian optimisation and CFD approach to maximise performance in a coiled reactor.•Near-optimal solutions are achieved with a modest number of iterations.•Desirable mixing features for achieving ‘good’ plug flow are discovered.•Automated, open-source method is formulated for optimising chemical reactors.