The purpose of gas processing is to remove the heavier hydrocarbons from process gases, to stabilize light naphtha by removing the gaseous hydrocarbons from it, and then to separate the refinery gases into components, such as pentanes for gasoline blending, butanes for alkylation and gasoline blending, LPG propane, and fuel gas.
The gas plant takes refinery gas from distillation units and other process units and separates out the gas liquid. Gases and liquids from various refinery units are fed to an absorber-deethanizer where C2 and lighter crude fractions are separated from heavier fractions by lean oil absorption and removed for use as fuel gas or petrochemical feed. The heavier crude fractions are stripped and sent to a debutanizer, and the lean oil is recycled back to the absorber-deethanizer. C3/C4 crude fractions are separated from pentanes in the debutanizer, scrubbed to remove hydrogen sulfide, and fed to a splitter where propane and butane are separated.
- Feed Input: Light gases, and Light naphtha
- Temperature / Pressure: Ambient to 350°F / 200 to 350 psi
- Products / Output: Off-gas, propane, saturate butane (SB), Light naphtha, and Heavy naphtha
- Major Equipment involved in the process: Compressor, isoabsorber, Diethanolamine (DEA) absorber, debutanizer, exchangers, fin fans, and pumps
- Safety Hazards: High temps & pressures, volatile light hydrocarbons, H2S, DEA, caustic, steam, and rotating equipment
Gas liquid separation is a continuous process and the streams are contained on piping and vessels. The potential for exposure is limited, but can occur during sampling, maintenance, or in the event of a leak, plant upset, or turnaround.
Skin, Eye: The gas processing units have the potential for skin contact with aliphatic and aromatic naphthas and liquefied light hydrocarbons (LPG). Accidental skin contact with the naphtha streams may cause slight to moderate irritation. Skin irritation can be severe if the liquid becomes trapped inside shoes or gloves. Avoid prolonged or repeated contact by using protective clothing, including impervious gloves. Because of its rapid evaporation, contact with the liquefied gas stream can cause cold burns of the skin and can damage the eyes. Wear protective equipment, including eye protection when.