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

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.