Hazards
Bhopal & Seveso incidents occurred after an exothermic exponential runaway reaction started.
When Important
- Exothermic batch reactions.
- Storage of reactive chemicals.
- Unexpected Polymerization or Decomposition.
Challenges in the Field
- Chemistry at increased temperature can be different or unknown to operators.
- Cooling can malfunction or might not be able to cope with the exponential increase of the reaction rate.
Options to Get it Right
- Understand the chemistry and side reactions at abnormal conditions like elevated temperature.
- Understand the point where cooling can not cope with the exponential heat of the reaction (point of no return).
- Assure good design data is available on heat balance of all the reactions involved (like DSC curves).
- Understand the effect of malfunctioning cooling.
- Have a reactivity matrix available & make sure operators know the critical combinations of chemicals to avoid.
- Assure cooling is reliability and have back-up cooling available.
- Validate inhibitors are present as applicable.
- Have a last line of defence like Interlocks, Breaker plates, Bunkers.
- Have an emergency procedure: Run away in a runaway reaction!
This page only summarises the guidance – refer to the EPSC website for further information.
For more information on our Process Safety Fundamentals (or other) playing cards please contact us.
