Experimental and numerical study of the synthesis of isopropyl propionate in microreactor

Microreactors have been widely used with advantageous of large specific surface area, excellent heat and mass transfer performance. In this paper, experimental and numerical study were carried out to analyze the thermal hazard associated with the synthesis of isopropyl propionate in a microreactor. In the experimental study, the effects of reaction temperature, catalyst amount, channel diameter and flow rate were investigated. The optimal condition was as follows: channel diameter 2 mm, amount of catalyst 0.8%, reactant ratio n(propionic anhydride): n(isopropanol) = 1:1, flow rate V (propionic anhydride + isopropanol) = 1 ml/min, and reaction temperature T = 60 °C. In this condition, the conversion of propionic anhydride reached 89.9% and the space–time yield was 2.39 × 10⁶ mol m⁻³ h⁻¹. Computational Fluid Dynamics (CFD) technology was used to develop a model of the microreactor with this optimum condition. It showed that the flow rate of coolant and material of the microreactor had a great influence on the distribution of temperature. A lower cooling flow rate would lead to the formation of a heat transfer barrier in the cooling jacket. Under the same condition, a silicate glass microreactor had better heat transfer performance and was safer than other options.