Gasoline Refineries

gas-refinary
Pyramid E&C builds topping refineries and hydro skimming refineries to produce automotive fuels, i.e., Diesel and Gasoline from Crude Oil and Condensate. The building blocks of these refineries include atmospheric distillation, hydro treating, reforming, and gas treating. The yields and the treatment required depend on the API gravity, sulphur, and other properties of the crude. Utilities include a fuel gas system and hydrogen purification.

Crude oil is first treated in a desalter unit where salt in water, or brine, is removed. The crude oil is heated in a fired heater from which it enters the flash zone of an atmospheric column. Natural gas condensate can also be included in the feed or introduced directly into the column. The crude oil mixture is separated into different cuts by boiling range. The crude column produces naphtha, kerosene, and gas oil as the side streams. The crude column bottoms, also called reduced crude, are used as fuel oil.

Treatment processes in a Hydro skimming refinery are used to remove sulphur which is converted to sulphur oxides when gasoline or diesel fuels are burned, thus creating pollution. Nitrogen is also partially removed, which reduces the nitrous oxides that are created when fuel is burned.

The wide naphtha cut is hydro treated. The hydro treating process uses a catalyst to remove sulphur. The hydro treated naphtha is fed to a naphtha splitter. The light naphtha is processed in an isomerisation unit to increase its octane prior to gasoline blending. The heavy naphtha is processed in a reformer which creates aromatic rings to increase octane and also liberates hydrogen. The reformer is a fixed-bed semi-regen type catalyst system. The hydrogen is purified in a Pressure Swing Absorption unit and used for the hydro treaters

The Light Ends System includes amine treating to remove hydrogen sulphide and also can fractionate butane for use in gasoline blending or propane and butane for product LPG (Liquefied Petroleum Gas).

The kerosene side stream can be sweetened using a fixed-bed Merox process to remove mercaptan sulphur. Alternatively, it can be hydro treated to remove sulphur. It can make a kerosene fuel or jet fuel product, or can be blended to diesel product.

The gas oil side stream is mixed with hydrogen and treated in a fixed-bed hydro treater to remove sulphur and nitrogen. The sulphur is converted to hydrogen sulphide, which is removed in the fuel gas treatment system.

Depending on the viscosity, reduced crude can be used as fuel oil directly. Alternatively, kerosene or diesel can be blended with the reduced crude to produce fuel oil.

Name

Gasoline Sulphur
Limit, ppm

Diesel Sulphur
Limit, ppm

Euro 2

500

500

Euro 3

150

350

Euro 4

50

50

Euro 5

10

10

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