Thermal Hazard Assessment in Chemical Processes

Thermal hazard assessment addresses the potential for dangerous heat release, accumulation and runaway in chemical processes. Exothermic reactions, decomposition and self-heating phenomena can lead to rapid temperature rises, fire or explosion if not properly controlled. Assessment protocols integrate calorimetric measurements, kinetic modelling and adiabatic calorimetry to determine critical safety parameters such as self-accelerating decomposition temperature, onset temperatures, activation energies and time to maximum rate. Advances in micro-calorimetry and predictive data-driven models have enhanced early detection of unstable reactions and guided the design of safe storage, transport and reactor systems. This multidisciplinary domain spans reactor engineering, materials science and thermochemistry, with applications in solvent management, polymerisation safety and peroxide decomposition. Harmonising small-scale kinetic data with industrial-scale conditions remains essential to ensure robust hazard evaluation across diverse chemical industries.

Research from Nature Portfolio

Recent studies have employed simultaneous thermogravimetric and calorimetric analyses to quantify how trace metal contaminants alter solvent stability. In one investigation, copper(II) and zinc(II) ions were shown to lower the thermal decomposition onset of monoethanolamine by over 10 °C and introduce distinct two-stage exothermic behaviour. Activation energies increased markedly in the presence of metal salts, highlighting the role of corrosion products in triggering thermal hazards. These insights inform improvements in solvent treatment and storage strategies to bolster intrinsic safety in petrochemical operations.

Thermal Hazard Assessment in Chemical Processes publication trend

The graph below shows the total number of articles in thermal hazard assessment in chemical processes across all publications each year (not limited to Nature Index journals).

Technical terms

Thermal runaway: A self-accelerating exothermic reaction in which heat generation exceeds removal, leading to uncontrollable temperature rise.

Self-Accelerating Decomposition Temperature (SADT): The lowest temperature at which a substance, in its normal packaging, will undergo self-accelerating decomposition.

Differential Scanning Calorimetry (DSC): A technique that measures heat flow into or out of a sample as it is heated or cooled, used to identify exothermic or endothermic events.

Thermogravimetric Analysis (TG): A method that monitors mass change of a sample as a function of temperature or time, revealing decomposition steps and stability limits.

Adiabatic calorimetry: A calorimetric approach in which a sample is thermally insulated to assess heat release under near-adiabatic conditions, mimicking worst-case scenarios.

Time to Maximum Rate under isothermal conditions (TMRiso): The time interval before the maximum reaction rate is reached at a given constant temperature, indicating how rapidly a runaway may develop.

Activation energy (Ea): The minimum energy barrier that must be overcome for a chemical reaction or decomposition to proceed, derived from kinetic analysis.

References

1. Thermokinetics and gas emission characteristics of nitrification waste under different oxygen contents by using TG-FTIR technique. Case Studies in Thermal Engineering (2023).
2. Thermal Decomposition and Nonisothermal Kinetics of Monoethanolamine Mixed with Various Metal Ions. Scientific Reports (2019).
3. Thermal Hazard Evaluation of Tert-Butyl Peroxy-3,5,5-trimethylhexanoate (TBPTMH) Mixed with Acid-Alkali. Materials (2022).