Executive Summary
When a major refinery took its hydrogen plant offline for turnaround, fuel gas consumption dropped dramatically — creating up to 3 million SCFD of excess fuel gas vapor control problem that could not be routed to the flare without violating the state and federal emission controls laws.
Envent engineered and deployed a parallel high-pressure thermal oxidation system with >99.99% DRE, operating under an approved Alternative Monitoring Plan (AMP). The result: zero flaring, zero incidents, and the fastest hydrogen plant turnaround in the refinery’s history.
Project At A Glance
- Location: U.S. Gulf Coast Refinery
- Challenge: 3 Million SCFD Excess Fuel Gas During H₂ Plant Turnaround
- Solution: Dual-Stream High-Pressure Thermal Oxidation with AMP
- Outcome: Zero Flaring, Zero Incidents, Record Turnaround Speed
The Challenge: Excess Fuel Gas During Hydrogen Plant Shutdown
Taking the hydrogen plant offline reduced refinery fuel gas demand, leaving up to 3 million SCFD of excess high-pressure fuel gas with no sink.
Key Constraints Regulatory Compliance The EPA Refinery Sector Rule (RSR) – 40 CFR §63.670(o) prohibits routine flaring during MSS events and requires ≥98% destruction efficiency with approved monitoring. Uncontrolled releases could trigger fines and Title V deviations.
Operational Demands High-pressure, variable-composition fuel gas required precise pressure control and detonation protection without delaying the critical-path hydrogen plant schedule.
Safety & Emission Risks Routing to the flare would exceed capacity and visibility limits; carbon or recovery alone could not handle the volume safely.
Official EPA Resources
- Refinery Sector Rule Overview – Flare minimization and work-practice standards.
- Alternative Monitoring Plans (AMPs) – Approved alternatives for continuous monitoring during MSS events.
Envent’s Engineered High-Pressure Thermal Oxidation Solution
Envent conducted a detailed pressure-loss study and PHA to design a parallel dual-stream system:
Treatment Process & Destruction Details Pressure Control Custom regulator systems sized for two high-pressure streams, maintaining safe delivery to oxidizers.
Safety Enhancements Specialty auxiliary detonation arrestors + control/isolation valves for unforeseen conditions.
Emission Controls and Vapour Destruction from pipe and vessels with upgraded controls and real-time analyzers delivered >99.99% DRE under the approved AMP.
The system operated continuously with 24/7 Envent operators, handling the full 3 million SCFD load.
Proven Benefits: Zero Flaring, Record Turnaround
| Benefit | Project Impact |
|---|---|
| Emissions Compliance | Zero flaring, zero fines, full RSR/MACT 2 & AMP compliance |
| Destruction Efficiency | >99.99% vs. flare’s typical 95% |
| Turnaround Schedule | Fastest hydrogen plant turnaround in refinery history |
| Safety & Reliability | Zero incidents despite high-pressure, variable fuel gas |
| Operational Flexibility | Parallel streams + custom controls handled all upsets |
The refinery completed the hydrogen plant turnaround faster than ever before, generating above-average profits for the year.
Planning a hydrogen plant or fuel gas imbalance turnaround? Get your Free EPA RSR / AMP Compliance Review & Quote today. Call Envent’s Turnaround Division at 888-997-9465 or email [email protected] — we keep your flare off and your schedule on track.
