Ortsaufgelöste Reaktionskalorimetrie in mikrostrukturierten Reaktoren

Design and characterization of a flow reaction calorimeter based on FlowPlate® Lab and Peltier elements

Microscale flow reaction calorimeter based on commercially available hastelloy C-22 microreactor for isoperibolic and isothermal operation mode.

Reactor performance estimation in microscale flow calorimeter for rapid characterization of exothermic reactions

Abstract

Continuous flow calorimeters are a promising tool in process development and safety engineering, especially for flow chemistry applications to characterize the heat release and kinetic parameters of rapid chemical reactions. In this study, the digital accompaniment of an isoperibolic flow calorimeter for characterization of exothermic reactions is presented. To support experimental planning and evaluation, computational fluid dynamic simulations are carried out for single-phase flow in the microreactor. The residence time distribution is obtained and used for estimation of conversion and temperature profiles along the microreactor channel. This leads to an integration of CFD simulations into the calorimeter’s software-guided workflow reducing the experimental effort regarding the determination of thermokinetic data. The approach is tested for a highly exothermic test reaction, which provides further hints for future investigations.

Article highlights

• Estimation of conversion and temperature profiles within a microscale calorimeter

• Combination of CFD simulations and reactor performance estimation

• Approach was tested for highly oxidation of sodium thiosulfate

• Estimated conversion and temperature profiles are in good agreement with experimental data

Graphical abstract

Measuring Kinetics in Flow Using Isoperibolic Flow Calorimetry

Continuous flow calorimeters are a promising tool in process development and safety engineering, particularly for flow chemistry applications. An isoperibolic flow calorimeter is presented for the characterization of exothermic reactions. The calorimeter is adapted to commercially available plate microreactors made of glass and uses Seebeck elements to quantify the heat of reaction. For automation of calibration procedures and calorimetric measurements, the device is connected to a lab automation system. Reaction enthalpy of exothermic reactions is determined via an energy balance of the entire calorimeter. Characterization of reaction kinetics is carried out via a local balancing of the individual Seebeck elements without changing the experimental setup, while using the previous measurements and additional ones at higher flow rates. The calorimeter and the associated measurement procedures were tested with the oxidation of sodium thiosulfate using hydrogen peroxide. Reaction enthalpy was determined to be 594.3 ± 0.7 kJ mol−1, which is within the range of literature values.

Characterization of reaction enthalpy and kinetics in a microscale flow platform

We report an isothermal flow calorimeter for characterization of reaction enthalpy and kinetics.