(446g) Heat Transfer Characterization in Flow Reactors for Continuous Pharmaceutical Oxidations

The small-molecule pharmaceutical and specialty chemical industries are undergoing a paradigm shift to modular continuous operation. That shift necessitates a strong understanding of the benefits of continuous, or flow operation which can be more controlled, cost-effective, and efficient than traditional batch operation. However, the knowledge gap in the workforce is a key challenge to the transition from batch to flow, motivating the development of a hands-on training course on the fundamentals of heat transfer, mixing, separation, microreactor assembly in flow chemistry. The work highlighted herein aims to lay the foundation of heat transfer characterization in flow and to show the advantage of flow reactors through modeling and lab-scale experiments. Efficient heat transfer is essential for the industries’ highly energy-intensive processes which require fast cooling. We used the highly exothermic decomposition of hydrogen peroxide as a case study. It’s a thermal runaway reaction that can get out of control due to the accelerated heat generation, requiring a reactor with a high heat transfer coefficient to avoid costly cooling and safety concerns. Our work includes heat transfer simulations and experiments to characterize the heat transfer coefficient of different reactors. Temperature and conversion modeling was done in a batch reactor, a continuously stirred tank reactor (CSTR) and a plug flow reactor (PFR). Those reactors were also characterized experimentally, providing a comparison between batch and flow performance. Due to better mixing and a higher surface-to-volume ratio, flow reactors exhibit higher performance and control than batch reactors of the same volume.