Emergency Procedures

Chapter from the Hydroprocessing Operations Guide.

HYDROPROCESSING EMERGENCY PROCEDURES

Emergency Response Frameworks

Emergency	Immediate Action	Secondary Action	Key Parameters to Monitor	Do NOT	Typical Cause	Recovery
Loss of Feed	Maintain H2 circ at reduced rate Reduce heater firing Close feed block valve	Stabilize reactor temps Monitor for temperature excursions Prepare for shutdown if extended	Reactor temperatures Recycle gas flow Separator levels	Do NOT lose H2 circulation Do NOT leave heater at full fire	Pump trip, upstream upset, blocked line	Re-establish feed slowly when available Watch for exotherms on feed introduction
Loss of Recycle Gas	Emergency shutdown heater Maintain MU H2 if possible Begin controlled depressuring	Alert operations to potential H2 starvation Monitor reactor ΔTs for runaway	Reactor temperatures System pressure All bed thermocouples	Do NOT continue firing heater Do NOT delay response	Compressor trip, suction valve close, motor failure	Restore compressor Slow pressuring and heat-up Resulfide if extended outage
Loss of Makeup H2	Continue recycle gas at max rate Reduce throughput 30-50% Reduce severity (lower T)	Monitor H2 purity decay Prepare for shutdown if H2 drops below limit	Recycle gas H2 purity H2 consumption vs supply Product quality	Do NOT maintain full throughput Do NOT increase temperature	H2 plant upset, PSA failure, supply line issue	Restore H2, increase throughput gradually
Excessive Temperature Rise	Maximize quench to affected bed Reduce heater outlet temperature Reduce feed rate	If uncontrolled: emergency depressure Do NOT delay if T exceeds metallurgical limit	Individual bed temperatures Rate of temperature increase Peak temperature vs. limit	Do NOT wait to see if it stabilizes Do NOT close quench valves	Feed contaminant, catalyst bed issue, channeling	Root cause investigation before restart May need catalyst replacement
H2S Breakthrough	Reduce severity (lower WABT) Reduce feed rate Increase H2/oil ratio	Sample products for sulfur Check if catalyst is exhausted (EOR)	Product sulfur Recycle gas H2S All bed thermocouples	Do NOT increase temperature (may worsen breakthrough)	End of run, feed upset, catalyst poison	Address root cause May indicate catalyst change needed
Power Failure	Emergency procedures per unit SOP Emergency diesel for critical systems Maintain H2 if steam-driven compressor	Check all pump status Verify emergency cooling Prepare for safe park or shutdown	Everything — DCS backup critical Reactor temperatures Separator levels	Do NOT forget to verify instrument air Do NOT neglect cooling systems	Utility failure, grid issue, local fault	Systematic restart per procedure Check all equipment before restarting

Source: Hydroprocessing_Ops_Guide_v1.xlsx · sheet “Emergency Procedures”

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