Continuous milli-scale reaction calorimeter for direct scale-up of flow chemistry
Reaction calorimetry of flow processes is important for scale-up and safety in flow chemistry. Due to the increasing number of flow processes, corresponding flow calorimeters are required as an alternative or addition to high-precision batch calorimeters. In this work, a milli-scale isoperibol continuous flow calorimeter was used to measure the heat of reaction based on an elaborated heat transfer model. This allows for reaction calorimetry without calibration. The model was tested with a selective, fast and exothermic neutralization reaction of acetic acid and sodium hydroxide at different flow rates, concentrations and viscosities. Deviations of the mean heats of reaction from the literature values were only about 2%. The calorimetric data can further be used for direct scale-up with tube bundle mixer heat exchangers having similar heat transfer characteristics. In addition, a reaction screening at different flow rates allows to find the maximum temperature and maximum heat generation. This data is useful in safety analyses of continuous processes. For these reasons, continuous reaction calorimetry provides a practical scale-up tool for flow processes.
Journal of Flow Chemistry 2021 Oct.