We use water to produce steam and to keep the Refinery product streams and equipment cool, similar to the cooling system in cars.
Cooling the water in large wooden “cooling towers” and re-circulating it minimizes the amount of fresh water needed. The water falls in droplets from the top to the bottom of the cooling tower. Large fans pull air from the bottom to the top.
The falling water cools when it encounters the rising air and forms billowing clouds of steam. These plumes of white clouds, which can be seen from miles away, are not smoke. Rather, they consist of condensed water vapor that is formed during the cooling process.
The clouds behave like fog, dissipate quickly, and do not harm the environment.
The Refinery’s water re-circulation rate for cooling systems is about 400 million gallons per day. Steam condensate recovery and recycle are about 7 million gallons per day.
All the water used in the Refinery’s processes is supplied by the Jackson County Industrial Water System, which draws from the Pascagoula River and not from groundwater resources.
The water is pumped from the river through dual pipelines to the Bayou Casotte treating facility where clarification, filtration, and pH adjustments are done. Treated water is transported by pipeline to the Refinery and other Bayou Casotte area industrial users.
To replenish evaporative and consumed water losses, the Refinery uses about 16 million gallons of water per day from the Jackson County Industrial Water System, which is operated by the Jackson County Port Authority.
The refinery’s Utilities Area and a Mississippi Power Company co-generating plant, located adjacent to the Refinery, supply the required utilities for Chevron Pascagoula Refinery’s continuous operation.
Our Utilities Area supplies some electrical power and most steam requirements, as well as all the compressed air, fuel gas, fire water, process water, drinking water, nitrogen, and both high and low pressure boiler feed water.
Mississippi Power Company’s co-generating facility provides 85 percent of the Refinery’s electricity needs and about 60 percent of our steam requirements. The co-generating units’ waste heat recovery boilers generate and supply steam to the refinery at 600 pounds per square inch and 650°F.
Oil-To-Oil Heat Exchangers
In order to process the crude oil, many of the refinery’s process units require heat. In an effort to maximize energy efficiency, heat is recovered from hot product streams leaving the refinery’s process units by oil-to-oil heat exchanger equipment.
This heat is transferred into the cold feed streams coming into the process units, which reduces the amount of fuel gas required for process heating.
Since recovering heat energy minimizes the fuel burned, it also helps keep the environment clean. Saving energy has a direct effect on profitability by reducing our operating costs.
Covering the refinery’s equipment and piping with insulation prevents heat from escaping into the atmosphere. Insulation not only saves energy (and reduces operating costs) it also provides safety protection to our employees by covering the hot equipment and piping.
Loading Displaces Vapors
During loading of bulk liquid tankers or barges, the liquid introduced displaces vapors from previous cargoes that still exist in the tank and those vapors generated by the current cargo loading. The vapors of certain cargoes contain volatile organic compounds (VOCs) that include hydrocarbons, oxygenated hydrocarbons, and organic compounds containing nitrogen or sulfur.
Chevron MVR System meets federal requirements
The Clean Air Act of 1990 requires the control of VOC emissions, and the Marine Vapor Recovery units at the refinery’s marine facility meet Coast Guard (Title 33, Code of Federal Regulations, Part 154) and Clean Air Act (Title 40, Code of Federal Regulations, Part 61 and 63) requirements.
The Pascagoula Refinery’s Marine Vapor Recovery (MVR) system includes two units that serve Berths 2-5 and a separate unit at Berth 6, which is located a good distance away from Berths 2-5.
MVR at Main Product Dock (Berths 2 - 5)
- Units “A” and “B”; each with 35,000 barrels liquid loading per hour vapor recovery capacity; combined vapor recovery capacity 70,000 barrels per hour of liquid loading.
- Recovers vapors from VOC emissions containing vapor pressure of 1.5 psi or greater.
- The process uses Lean Oil Absorption. While a regulated product is being loaded, vapors are recovered from the marine vessels by a header system. This header carries the vapors, either by pressure from loading or pulled by vapor boosters that provide a slight vacuum on the header. The vapors are routed through a chilled absorber, entrained in the Lean Oil, then passed through a series of exchangers, and then into a stripper column where the VOCs are stripped out by heat and held in a holding drum. The recovered VOCs are then pumped in to a crude transfer line for reprocessing.
MVR at Berth 6
MVR at Berth 6 provides vapor recovery for Berth 6 only and has vapor recovery capacity of 8,000 barrels per hour of liquid loading. Like its sister unit at the Main Product Dock, this unit uses the Lean Oil Absorption system, but does not feature the vapor boosters. This unit recovers vapors from special products and chemicals including Penhep, Hydrobate, Heptane, Hexane, Penhex and Straight-run (or unblended) gasoline.
Marketing Terminal Vapor Recovery Unit
As a tank truck drops (delivers) new product into the underground storage tank at Chevron stations, the vapors created during the drop are pushed back into the tank truck and stored there.
As the tank truck loads new product at the Marketing Terminal using a “bottom loading” method, the product being loaded into the bottom of the tank pushes the collected vapors into a vapor recovery hose connected to the recovery system. The Adsorb/Absorb vapor recovery unit condenses the vapors, recovering about 2 gallons of gasoline per 1000 gallons loaded product.
We welcome comments and questions about our environmental policies
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Among the Animals: Mississippi
A champion of environmental education and early childhood development programs, Chevron’s Pascagoula Refinery is proud to support both efforts by sponsoring
Among the Animals: Mississippi. This engaging book will introduce Mississippi’s youngest residents to the wild wonders of their home state and lay the foundation for a lifetime of environmental awareness.