Thermal and Kinetic Research on a Highly Exothermic Condensation Reaction by Powerful Calorimeters

Abstract

From the safety point of view, thermal risk analysis in the process industry is generally of significant importance and often requires calorimetric and kinetic modeling. These techniques were applied for the first time in the study of a highly exothermic condensation reaction, which is used to prepare 2,2′-methylene-bis(4,6-di-tert-butylphenol) phosphate chloride, a quite important intermediate in the fine chemical industry. The thermodynamics properties such as reaction heat, adiabatic temperature rise, and specific heat capacity of the synthesis reaction were experimentally investigated under isothermal conditions using a robust process analytical technology-based in-line reaction calorimeter EasyMax. A kinetic correlation model was developed based on the calorimetry and subsequently verified. This exhibited a much more efficient and convenient way to study the reaction kinetics compared with the conventional off-line determination of molar concentration or conversion. An accelerating rate calorimeter was used to reveal the thermal controllability of the reaction system as well as some potential hazards. The thermal and kinetic parameters lay a solid foundation for the design and safe operation of reactors. The related methods are also anticipated to be extended to a wide range of similar highly exothermic reactions.

Chemical Recycling of Step-Growth Polymers Guided by Le Chatelier’s Principle

“…The polymerization of SGPs, whether proceeding via condensation or addition mechanisms, is typically characterized by an exothermic nature (Δ H < 0 kJ mol –1 ). , Although thermal treatment is commonly employed to initiate the polymerization, the heat is to overcome the activation energy. If two reactants are highly reactive, for example isocyanates and amines, room temperature is enough to trigger the reaction between them to form ureas .…”

Thermal characterization of highly exothermic flash chemistry in a continuous flow calorimeter

“…Reaction calorimetry is normally performed using stirred batch reactors. 22 Commercially available batch calorimeters, such as the RC1 from Mettler-Toledo, are widely used in industrial and academic laboratory settings. 23,24 However, despite the drawbacks of batch calorimetry, such as a significant holdup and safety issues, 25,26 the limitations when applied to flash chemistry are even greater.…”