Refined Products

The most important refinery product is motor gasoline, a blend of hydrocarbons with boiling ranges from ambient temperatures to about 205°C. The important qualities for gasoline are octane number (antiknock), volatility (starting and vapour lock), and vapour pressure (environmental control). Additives are often used to enhance performance and provide protection against oxidation and rust formation. Gasoline is one of the most high-valued products of the refinery due to high margins and large volumes.

Liquefied Petroleum Gas (LPG)

The gases obtained from crude oil distillation are ethane, propane, and n-butane isobutene.

These products cannot be produced directly from the crude distillation and require high-pressure distillation of overhead gases from the crude column. That is why the transportation

of LPG is very expensive and limited in size. C3 and C4 particularly are recovered and sold as liquefied petroleum gas (LPG), while C1 and C2 are generally used as refinery fuel. LPG is produced for use as fuel, and it is an intermediate material in the manufacture of petrochemicals.

Naphtha

C5 -205°C ASTM (American Society for Testing and Materials) cut is generally termed naphtha. There are many grades and boiling ranges of naphtha. Naphtha is used as feedstock for petrochemicals either by thermal cracking to olefins or by reforming and extraction of aromatics. Also some naphtha is used in the manufacture of gasoline by a catalytic reforming process.

Kerosene

Kerosene is a refined middle-distillate petroleum product that finds considerable use as a jet fuel and around the world in cooking and space heating. When used as a jet fuel, some of the critical qualities are freeze point, flash point, and smoke point. Commercial jet fuel has a boiling range of about 190°-274°C, and military jet fuel 54°-288°C. Kerosene, with less-critical specifications, is used for lighting, heating, solvents, and blending into diesel fuel.

Distillate Fuels

Diesel fuels and domestic heating oils have boiling ranges of about 205°-371°C. The desirable qualities required for distillate fuels include controlled flash and pour points, clean burning, no deposit formation in storage tanks, and a proper diesel fuel cetane rating for good starting and combustion. Diesel grades have an ASTM end point of 343-371°F. Diesel fuel is a blend of light and heavy distillates and has an ASTM boiling range of approximately 177-357°C.

Vacuum Gas Oil

Vacuum gas oil is the distillate boiling between 371 and 538°C. This is not a saleable product and is used as feed to secondary processing units, such as fluid catalytic cracking units, and hydro crackers, for conversion to light and middle distillates.

Residual Fuel Oil

Hydrocarbon material boiling above 538°C is not distillable and consists mostly of resins and asphaltenes. This is blended with cutter stock, usually kerosene and diesel, to meet the viscosity and sulphur specifications of various fuel oil grades. Many marine vessels, power plants, commercial buildings and industrial facilities use residual fuels or combinations of residual and distillate fuels for heating and processing. The two most critical specifications of residual fuels are viscosity and low sulphur content for environmental control. Residuals have little value for refinery that is without a cracking capacity to convert the large molecules to smaller. For those refineries that do have this option, buying cheap residuals to make high-value refined products can be very lucrative.

Coke and Asphalt

Coke is almost pure carbon with a variety of uses from electrodes to charcoal briquettes.

Asphalt, used for roads and roofing materials, must be inert to most chemicals and weather conditions. These two products are low-value products since they have low sales prices in the market.

Solvents

A variety of products, whose boiling points and hydrocarbon composition are closely controlled, are produced for use as solvents. These include benzene, toluene, and xylene.

Petrochemicals

Many products derived from crude oil refining, such as ethylene, propylene, butylenes, and isobutylene, are primarily intended for use as petrochemical feedstock in the production of plastics, synthetic fibres, synthetic rubbers, and other products.

Lubricants

Special refining processes produce lubricating oil base stocks. Additives such as demulsifies, antioxidants, and viscosity improvers are blended into the base stocks to provide the characteristics required for motor oils, industrial greases, lubricants, and cutting oils.

The petroleum products are classified in a wide variety of different ways within oil industry:

• Refiners distinguish between light products (whose molecules have a low number of carbon atoms, i.e. gas and gasolines), middle distillates (kerosene, automotive gas

and gasolines) and heavy products (with long carbon chain molecules, i.e. heavy fuel and bitumen).

• For bulktransport, transport are categorised as white products, i.e. motor gasoline, jet fuel, automotive and heating gas oil; and black products i.e. fuel oil and bitumen.

• Dealers distinguish between main products and specialities, however the boundary is not clear. For main products, volumes are large and differentiation is limited so the product range is not extensive. Margins for main products, e.g. motor fuels, jet fuel, heating gas oil and heavy fuel oil including bunkers, are relatively low. Sales of specialities, e.g. LPG, aviation gasoline, lubricants and bitumen, are low in terms of volume but give a high added value, either in terms of the product itself or the service provided.