Process Units
Our St Charles facility consists of nine integrated process units operating 24 hours a day, year-round. The crude throughput design is 47,000 barrels per operating day, with seasonal turnaround typically scheduled for January each year.
Unit 1 — Crude Distillation (CDU)
Atmospheric pipestill (38,000 bbl/d) and vacuum tower (9,000 bbl/d). Heat integration with the hydrotreater and reformer recovers approximately 78% of preheat duty. The crude feed slate is predominantly Light Louisiana Sweet (LLS) and Heavy Louisiana Sweet (HLS), with periodic runs of Mars and Eagle Ford WTI.
Unit 2 — Naphtha Hydrotreater (NHT)
1,300 psig hydrotreater; sulfur outlet specification < 0.5 ppm S to protect downstream reformer catalyst. Designed by UOP, last catalyst change Q3 2024.
Unit 3 — Continuous Catalytic Reformer (CCR)
UOP CCR Platforming™; product RON 99.5 minimum. Hydrogen output ~32 MMscf/d serves the hydrotreater, isomerization unit, and the diesel hydrotreater.
Unit 4 — Diesel Hydrotreater (DHT)
Two-stage ULSD service to 10 ppm sulfur EPA Tier 3 specification. Throughput 18,000 bbl/d of straight-run diesel + LCO.
Unit 5 — Isomerization (Penex)
Light-naphtha isomerization for high-octane gasoline blendstock; 6,200 bbl/d. UOP Penex™ technology.
Unit 6 — Sulfur Recovery (SRU)
Two-stage modified-Claus train; 480 long-ton/day sulfur recovery. SRU tail gas is fed to a SCOT-type absorber for >99.8% recovery. Liquid-sulfur product is shipped via rail and barge to fertilizer co-operatives.
Unit 7 — Hydrogen Plant
SMR train rated 35 MMscf/d; supplements CCR hydrogen for hydrotreater service during reformer downtime.
Unit 8 — Tank Farm & Blending
74 storage tanks totaling 1.2 million barrels of working storage. Floating-roof tanks for gasoline, jet, and crude; cone-roof for diesel and intermediates. Veeder-Root automatic tank-gauging across all working tanks.
Unit 9 — Marine & Truck Loading Rack
Two-berth dock with 12-inch and 16-inch loading arms (gasoline, jet, diesel). Truck rack: 4 bays, top-loading with vapor recovery. Rail rack: 3 spurs, dedicated to sulfur, jet, and asphalt.
Production & Markets
| Product | Capacity (bbl/d) | Primary Customer Class |
|---|---|---|
| Conventional gasoline (87/89/93) | 17,500 | Wholesale jobbers, Gulf retail |
| Jet fuel (Jet-A) | 9,400 | MSY airport, military aviation contracts |
| Ultra-low-sulfur diesel | 13,800 | Gulf marine, regional trucking |
| Naphtha (petrochem feedstock) | 2,400 | Gulf petrochemical complex |
| Liquefied petroleum gas (LPG) | 1,800 | Regional distributors |
| Sulfur (elemental) | 480 t/d | Fertilizer co-ops, sulfuric-acid producers |
Operations Control
The plant is operated from a central control room staffed continuously by DCS operators, board operators, and a shift supervisor. The control system is a Honeywell Experion PKS DCS (R432.1) federated with an OSIsoft PI historian on the data layer. Process safety alarms are routed to the BMS through a SIL-rated Triconex layer.
- Operating philosophy
- Continuous production with planned January turnaround (45 days nominal). Slow startup & shutdown over 5–7 days each side.
- Reliability program
- API-580 based risk-based inspection (RBI), quarterly mechanical-integrity audits, condition-monitoring rounds twice per shift.
- Optimization
- Aspen RT-OPT real-time optimizer running on the crude unit and reformer; LP planning weekly via Aspen PIMS.