In the pharmaceutical and chemical industries, batch or semi-batch processes are most common in development, scale-up and production. Scaling a process from lab to plant is challenging and associated with numerous issues, including:
- Heat transfer
- Cooling capacity
- Reactant accumulation
- Mixing
- Mass transfer
Although personal experience and empirical data may be used to a certain extent, the investigation of chemical processes requires the involvement of several disciplines, such as characterization of equipment, exploration of thermodynamics, and mixing and mass transfer studies, as well as the research of the reaction kinetics and the hazardous potential.
Heat dissipation in a stirred tank reactor is decisive for the safety and efficiency of a process, and production times are often determined by the heat transport. If thermal resistances and reaction rates are only approximately known, then large safety margins must be applied. This results in an increase in batch times and decreases the efficiency of the process. As a result, scale-up models are used to predict or simulate heat transfer conditions in the plant reactor as accurately as possible. Empirical correlations with characteristic values are used to simplify complicated differential equations describing the system.
This application note describes how reaction calorimetry provides accurate measurement of the thermal resistances and the heat evolved from reactions in the laboratory.
