Executive Summary
A major Louisiana refinery faced a $7–8 million production loss during a 30-day coker flare + scrubber outage. All daily sour vents (H₂S from Coker, Diesel Hydrotreater, Sulfur Plant, Sour Water Stripper, and Gasoline Hydrotreater) would normally route to the shutdown scrubber — forcing the refinery to either shut units or send untreated sour gas to an ill-equipped backup flare.
Envent designed and installed a temporary high-pressure caustic scrubber system that treated all sour vents to <5 ppm H₂S/SO₂ before the backup flare — saving the full $8 million while keeping every unit online and 100% LDEQ Title V and EPA Refinery MACT 2 compliant.
Project At A Glance
- Location: Louisiana Gulf Coast Refinery
- Challenge: 30-day coker flare + scrubber outage → $8 MM production risk
- Solution: Temporary high-pressure caustic scrubber + 24/7 manned operation
- Outcome: $8 million saved, zero units shut, <5 ppm H₂S/SO₂ to backup flare
The Challenge: No Sour Vapor Path During Flare/Scrubber Outage
- Primary flare + dedicated sour scrubber taken offline simultaneously
- Daily sour vents from five major units (Coker, DHT, Sulfur Plant, SWS, GHT)
- Backup flare not rated for high H₂S/SO₂ loads
- Routing to amine system = $7–8 MM lost production
- Must comply with LDEQ Title V, and EPA Refinery MACT 2 (40 CFR 63 Subpart UUU) flare-minimization rules
Envent’s Temporary High-Pressure Caustic Scrubber Solution
Envent engineered a parallel sour-vapor bypass that tied into the existing flare header:
| Component | Specification & Link |
|---|---|
| High-Pressure KO Drums | Removed liquids before scrubbing |
| HP Stainless Steel Caustic Scrubbers | Custom-built, wet scrubbers for >99.99% H₂S/SO₂ removal |
| Custom High-Volume Blowers | Maintained normal header pressure |
| Automated Isolation Valves + Sensors | Real-time pressure, temperature, H₂S monitoring |
| 24/7 Manned Operation | Two Envent technicians per shift for 30+ days |
System achieved <5 ppm H₂S/SO₂ at backup flare inlet — well below permit limits.
Proven Results: $8 Million Saved, Zero Incidents
| Benefit | Delivered Outcome |
|---|---|
| Production Saved | $8 million — every unit stayed online |
| Emissions | <5 ppm H₂S/SO₂ to backup flare — zero violations |
| Safety | Zero incidents in Class I Div II environment |
| Compliance | 100% LDEQ Title V, LAC 33:III, and EPA RSR compliant |
| Execution | Installed under strict MOC, finished on time |
The refinery completed the turnaround with full production and zero environmental penalties.
Planning a flare or scrubber outage? Get your Free LDEQ Title V / EPA RSR Flare Bypass Plan & Quote today. Call Envent’s Louisiana Team at 888-997-9465 or Request a Quote → — we keep your units running and your flare off.
