Measuring enthalpy of fast exothermal reaction with infrared thermography in a microreactor

• A microsystem integrated with infrared camera is developed to measure the reaction enthalpy.
• The reaction enthalpy can be determined from the temperature rise of the capillary.
• Two reactions including homogeneous and heterogeneous reactions are performed.
• It can provide a quick, safe and non-intrusive method to obtain the temperature profiles for fast exothermic reactions.

In this paper, a microsystem integrated with infrared camera is developed to measure the reaction enthalpy of fast exothermic reactions. The microsystem is composed of a micromixer and a coiled capillary, which are all placed in a vacuum box to form an adiabatic environment. The fast exothermic reactions are started in the micromixer and then the temperature profiles of the capillary are measured via the infrared transparent window by the infrared camera. The reaction enthalpy can be determined from the temperature rise of the capillary. Two reactions which are homogeneous and heterogeneous respectively are performed with this method. The results show that the data obtained are in good agreement with the values reported in literature with the relative experimental errors less than 5%. Compared with the traditional calorimeter, the microsystem can provide a quick, safe and non-intrusive method to obtain the temperature profiles of the fast exothermic reactions.