Key Considerations and Applications of Common Calorimetric Laboratory Process Safety Tools to Evaluate Reactive Hazards

Evaluating chemical hazards is a crucial part of plant safety. In order to operate safely, hazards need to be identified and evaluated in order to either prevent, mitigate, or eliminate them.

Reactive chemical hazards are a special subset of chemical hazards that can be present whether the reaction is intended or not, and the results can have catastrophic consequences such as explosions, fires, or harmful chemical releases. It is critical to study both desired and undesired reactions to ensure that the proper safeguards, procedures, or safety related equipment are installed to provide adequate protection during process operations. Situations that result in unintended chemical reaction are referred to as upset scenarios. An upset scenario is a plausible abnormal process variation that is typically identified through a detailed reactive hazard analysis (RHA). An RHA is dedicated to the identification of reactive chemical hazards and can be considered a more focused version of a process hazard analysis (PHA).

It is essential to consider the presence of hazards throughout the various developmental stages or scale of production. This presentation provides an overview of various laboratory experimental techniques recommended for developing a safe chemical process. Focus will be on evaluating heat and pressure generation through the use of calorimetry. Techniques discussed will include Differential Scanning Calorimetry (DSC), Accelerating Rate Calorimetry (ARC), reaction/isothermal calorimetry, and low thermal inertia calorimetry (VSP2 & ARSST). The pros and cons of the various techniques, recommendations for collecting excellent data, and their typical safety applications will be discussed. Example data will be shared. Important safety parameters such as heat of reaction, instantaneous heat flow, adiabatic time to maximum rate (TMR), self-accelerating decomposition temperature (SADT), and reactive system emergency relief sizing will be discussed.