An Overview of Refinery Products and Processes

Distillation process separates the crude oil into boiling point fractions. The liquefied petroleum gas (LPG) constitutes the lowest boiling point (most volatile) product from a refinery and higher boiling fractions lead to most desirable distillate liquids, such as gasoline, jet fuel, diesel fuel, and fuel oil in the increasing order of boiling points, while asphalt is made from the residual fraction remaining after distillation.

Figure (1) Refinery Distillation Process

The following animation shows a refinery flow chart indicating some of the major refinery processes and refinery products. Note that the distillation process (Fractionation Tower) separates crude oil into a number of distillate fractions that are sent as feedstocks to different processes, some of which are interconnected. It is also important to recognize that petroleum refining not only produces transportation fuels and fuels for space heating or industrial furnaces but also produces materials needed for the operation of the combustion engines and paving the roads for vehicles to travel on.

Figure (1.1) indicates that chemical constitution and physical properties of crude oils are important parameters that guide the refinery configurations. The refining processes can be divided into four groups, as indicated. While the separation processes involve just physical phenomena, the conversion, finishing, and support processes require chemical changes, i.e., breaking chemical bonds to modify the molecular structure of the feedstocks. These changes are necessary to produce the fuels and materials in accordance with industrial/commercial specifications.

Figure (1.1)

Classification of Refinery Processes and Types of Refinery Products.

Figure ( 1.2 )(progressive image,) shows a more detailed refinery block diagram to show how different processes are integrated for producing the desired fuels and materials.

Separation processes, such as distillation, dewaxing, and deasphalting make use of the differences in the physical properties of crude oil components to separate groups of hydrocarbon compounds or inorganic impurities, whereas conversion processes cause chemical changes in the hydrocarbon composition of crude oils. For example, Fluid Catalytic Cracking process breaks chemical bonds in long-chain alkanes to produce shorter chain alkanes to produce gasoline from higher boiling gas oil fractions. Finishing processes involve hydrotreating to remove heteroatoms (S, N, and metals) and product blending to produce fuels and materials with desired specifications and in compliance with environmental and government regulations. Finally, supporting processes provide the recovery of the removed heteroatoms or heteroatom compounds, production of the hydrogen necessary for conversion and hydrotreating processes, and effluent water treatment systems.

Process Flow Diagram – Typical Oil Refinery

This is a schematic process flow diagram of the processes used in a typical oil refinery. This process flow diagram (PFD) example was redesigned from the Wikimedia Commons file: RefineryFlow.png. [commons.wikimedia.org/ wiki/ File:RefineryFlow.png]

"An oil refinery or petroleum refinery is an industrial process plant where crude oil is processed and refined into more useful products such as petroleum naphtha, gasoline, diesel fuel, asphalt base, heating oil, kerosene and liquefied petroleum gas. Oil refineries are typically large, sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units. In many ways, oil refineries use much of the technology of, and can be thought of, as types of chemical plants. The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot (tank farm) at or near an oil refinery for the storage of incoming crude oil feedstock as well as bulk liquid products.

(High Value Light Products : Gasoline , Jet Fuel, Diesel, etc …..)

Propane-Used as a feedstock for ethylene cracking , or blended into LPG for uses a fuel.

Butane--Used as a feedstock for ethylene cracking , or blended into LPG for uses as fuel.

LPG- (liquefied petroleum gas) – A blend of propane and butane used as fuel.

Light Naptha- – Used as feedstock into ethylene crackers.

Gasoline – Used as a transportation fuel for passengers cars and light trucks.

Aviation Gasoline– Used as an engine fuel in light aircraft.

Jet fuel – Used as a fuel for jet aircraft.

Kerosene fuel oi- Used as a residential cooking , heating, and lighting fuel.

Diesel- Used as a fuel for heavy-duty trucks, trains, and heavy equipment

Residue fuel oil – Used as a fuel in power generation and for large ocean-going ships (bunker fuel)

Many refineries also produce specialty or non-fuel products such as:

Asphalt - Used to pave roads and in the manufacture of building materials (e.g., roof shingles)

Base Oils – Used to make lubricating oils for use in industrial machinery and vehicle engines.

Propylene - Can be separated for sale to the petrochemicals industry.

Aromatics - Can be separated from reformate for sale to the petrochemicals industry.

Wax - Extracted from lubricating oil and either sold as a feedstock to specialty wax production (as slackwax) or treated at the refinery to a finished wax product.

Grease - Used as a solid lubricating oil, mostly in industrial uses.

White Oil - A colorless, odorless, tasteless oil used by the food, cosmetics, and pharmaceuticals industries.

White spirit - Naphtha range material used as an industrial or household solvent.

Sulphur - A contaminant when present in other products, but once separated, it can be sold as a feedstock to the petrochemicals industry.

Pet coke >- A by-product of the coking process that can be sold as a fuel for power plants and cement plants or to manufacture electrodes and anodes

The world’s refiners must fundamentally rethink how refineries are designed and operated.

( Petroleum Products – Marketing & Sales Group)