Ballinari D., Lugaresi O., Karunaratnage D., Barozzi M., Copelli S., 2026, From Thermo-Analysis to Operating Windows: A Framework for Safe Industrial Drying, Chemical Engineering Transactions, 126, 181-186.
Industrial drying of organic solids containing reactive functional groups may lead to severe safety issues when inappropriate operating conditions or equipment configurations are adopted. This work analyses the thermal hazards associated with the drying of epoxide-containing pharmaceutical intermediates through a real industrial accident occurred in a non-static dryer. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis coupled with DSC (TG-DSC) were used to characterize the thermal behaviour of the material, of its degradation products and of a structurally similar but non-epoxidized compound. The results show that the epoxide functional group is responsible for exothermic phenomena occurring at low temperatures, starting well before any detectable mass loss due to an eventual decomposition. Kinetic modelling of DSC data allowed the estimation of Time to Maximum Rate (TMR) and the identification of safe temperature-time domains for drying. A general protocol for the determination of safe drying conditions for reactive powders is finally proposed. The study demonstrates that drying of solid compounds characterized by epoxydic groups must be regarded as a chemically reactive operation rather than a purely physical unit operation.
