Commissioning

Chapter from the Field Operations Handbook.

COMMISSIONING & STARTUP

Startup Sequencing Principles

General Startup Sequence (hydroprocessing example):

1. Utility Systems First:
• Instrument air, nitrogen, steam, cooling water, power
• These must be stable before introducing hydrocarbons

2. Inert & Pressure Test:
• N2 purge to <0.5% O2
• Pressure hold test at operating pressure with N2
• Verify all instrumentation functions at pressure

3. Hydrogen Introduction:
• Slowly introduce H2 into N2 atmosphere
• Establish recycle gas circulation at cold conditions
• Verify H2 purity and system pressures

4. Heat-Up:
• Fire charge heater, ramp per catalyst vendor procedure
• Typical ramp: 25-50°F/hr
• Hold points per sulfiding/activation procedure

5. Catalyst Activation (see Hydroprocessing Guide for details)

6. Feed Introduction:
• Introduce feed at minimum rate
• Monitor all reactor temperatures for exotherms
• Line out at minimum rate before increasing

7. Increase to Design Rate:
• Step up in 10-20% increments
• Stabilize at each step before increasing
• Full rate operation → performance test conditions

Real-Time Troubleshooting During Startup

Common Startup Issues and Response:

• Leak at flange: Isolate if possible, depressure if needed, retorque or replace gasket
• Instrument malfunction: Use field gauge to verify, bypass instrument if safe, repair ASAP
• Pump cavitation: Check NPSH, verify suction strainer not plugged, reduce flow
• Compressor vibration: Check alignment, verify suction conditions, reduce speed
• High ΔP across reactor: Check feed quality, confirm no debris in bed, monitor trend
• Temperature excursion: Follow emergency procedure, use quench, reduce severity

Golden Rule: When in doubt, make the safe decision first, investigate second.
You can always restart. You cannot undo a safety event.

Source: Field_Operations_Handbook_v1.xlsx · sheet “Commissioning”

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