How do you design protection systems against reactor runaway in polymerization?

Runaway protection design: Hazard identification - exothermic polymerization can accelerate uncontrollably with temperature (Arrhenius kinetics). Heat balance - ensure cooling capacity exceeds maximum heat generation at all conditions. Detection systems - multiple independent temperature measurements, rate-of-rise monitoring, pressure monitoring for gas evolution. Automatic responses - staged based on severity: reduce feed rate, increase cooling, inject inhibitor/kill agent, emergency depressurization. Inhibitor systems - shortstop agents (hydroquinone, MEHQ) injected rapidly to terminate reaction. Mechanical design - vessels rated for emergency pressure, relief systems sized for runaway, containment for release. Process design - limit inventory, use continuous rather than batch where possible, implement proper mixing. Safety studies - reaction calorimetry (ARC, RC1) to characterize runaway kinetics, HAZOP, LOPA to verify protection adequacy.