Oil Refinery Processes

[Tatsuya Deals]

Refiningfuels is a complicated process. Check out this Into the Outdoors video, which features the Pine Bend refinery and describes the process of refining oil in a way that is understandable for all ages.

Crude oil is delivered to Pine Bend by a series of pipelines that stretch across the United States and Canada. Crude oil contains a mixture of molecules which are pumped or mined from underground reservoirs. In its natural state, it has very little value, so Pine Bend separates the molecules from each other by distilling the mixture into gasoline, propane and asphalt. Each molecule in crude oil boils at a different temperature, which is the basis of distillation.

The process of hydrotreating uses hydrogen and a catalyst to remove sulfur from oil by converting it to hydrogen sulfide. Sulfur removal is required to protect refinery processes and to minimize emissions from vehicles. Each day approximately 1,000 tons of sulfur are removed from our oil and processed in our sulfur plants. Sulfur is sold for use in the manufacturing of fertilizers, sulfuric acid, and a variety of pharmaceutical products, such as antibiotics.

Each individual refinery gasoline product is sent to a large storage tank. At this point, none of the individual gasoline products meet specifications for consumer use. The gasoline products are combined in a way that satisfies the specifications to be certified for sale. Pine Bend makes more than 100 grades of gasoline.

Pipelines deliver the vast majority of gasoline and diesel fuel to terminals, where the product is then loaded on trucks and delivered to retail gas stations. Other products distributed include sulfur, asphalt, petroleum coke, propane, butane, and jet fuel.

Petroleum refining processes are the chemical engineering processes and other facilities used in petroleum refineries (also referred to as oil refineries) to transform crude oil into useful products such as liquefied petroleum gas (LPG), gasoline or petrol, kerosene, jet fuel, diesel oil and fuel oils.[1][2][3]

Refineries and petroleum industries are very large industrial complexes that involve many different processing units and auxiliary facilities such as utility units and storage tanks. Each refinery has its own unique arrangement and combination of refining processes largely determined by the refinery location, desired products and economic considerations.

Prior to the nineteenth century, petroleum was known and utilized in various fashions in Babylon, Egypt, China, Philippines, Rome and along the Caspian Sea. The modern history of the petroleum industry is said to have begun in 1846 when Abraham Gessner of Nova Scotia, Canada devised a process to produce kerosene from coal. Shortly thereafter, in 1854, Ignacy Lukasiewicz began producing kerosene from hand-dug oil wells near the town of Krosno, Poland. The first large petroleum refinery was built in Ploesti, Romania in 1856 using the abundant oil available in Romania.[7][8]

In North America, the first oil well was drilled in 1858 by James Miller Williams in Ontario, Canada. In the United States, the petroleum industry began in 1859 when Edwin Drake found oil near Titusville, Pennsylvania.[9] The industry grew slowly in the 1800s, primarily producing kerosene for oil lamps. In the early twentieth century, the introduction of the internal combustion engine and its use in automobiles created a market for gasoline that was the impetus for fairly rapid growth of the petroleum industry. The early finds of petroleum like those in Ontario and Pennsylvania were soon outstripped by large oil "booms" in Oklahoma, Texas and California.[10]

Prior to World War II in the early 1940s, most petroleum refineries in the United States consisted simply of crude oil distillation units (often referred to as atmospheric crude oil distillation units). Some refineries also had vacuum distillation units as well as thermal cracking units such as visbreakers (viscosity breakers, units to lower the viscosity of the oil). All of the many other refining processes discussed below were developed during the war or within a few years after the war. They became commercially available within 5 to 10 years after the war ended and the worldwide petroleum industry experienced very rapid growth. The driving force for that growth in technology and in the number and size of refineries worldwide was the growing demand for automotive gasoline and aircraft fuel.

In the United States, for various complex economic and political reasons, the construction of new refineries came to a virtual stop in about the 1980s. However, many of the existing refineries in the United States have revamped many of their units and/or, constructed add-on units in order to: increase their crude oil processing capacity, increase the octane rating of their product gasoline, lower the sulfur content of their diesel fuel and home heating fuels to comply with environmental regulations and comply with environmental air pollution and water pollution requirements.

The crude oil distillation unit (CDU) is the first processing unit in virtually all petroleum refineries. The CDU distills the incoming crude oil into various fractions of different boiling ranges, each of which are then processed further in the other refinery processing units. The CDU is often referred to as the atmospheric distillation unit because it operates at slightly above atmospheric pressure.[1][2][14]

Below is a schematic flow diagram of a typical crude oil distillation unit. The incoming crude oil is preheated by exchanging heat with some of the hot, distilled fractions and other streams. It is then desalted to remove inorganic salts (primarily sodium chloride).

Following the desalter, the crude oil is further heated by exchanging heat with some of the hot, distilled fractions and other streams. It is then heated in a fuel-fired furnace (fired heater) to a temperature of about 398 C and routed into the bottom of the distillation unit.

The cooling and condensing of the distillation tower overhead is provided partially by exchanging heat with the incoming crude oil and partially by either an air-cooled or water-cooled condenser. Additional heat is removed from the distillation column by a pumparound system as shown in the diagram below.

As shown in the flow diagram, the overhead distillate fraction from the distillation column is naphtha. The fractions removed from the side of the distillation column at various points between the column top and bottom are called sidecuts. Each of the sidecuts (i.e., the kerosene, light gas oil and heavy gas oil) is cooled by exchanging heat with the incoming crude oil. All of the fractions (i.e., the overhead naphtha, the sidecuts and the bottom residue) are sent to intermediate storage tanks before being processed further.

The image below is a schematic flow diagram of a typical petroleum refinery that depicts the various refining processes and the flow of intermediate product streams that occurs between the inlet crude oil feedstock and the final end-products.

The diagram depicts only one of the literally hundreds of different oil refinery configurations. The diagram also does not include any of the usual refinery facilities providing utilities such as steam, cooling water, and electric power as well as storage tanks for crude oil feedstock and for intermediate products and end products.[1][2][15]

We advocate for public policies that promote growth and investment in the refining and petrochemical manufacturing industries to help drive our economy, add jobs, increase energy security and remain competitive in a global economy.

We offer a portfolio of first-in-class events that educate our members and other stakeholders on critical technical and advocacy issues, supporting the safety, security and success of the fuel and petrochemical industries.

Refining turns crude oil into usable products.

Petroleum refining separates crude oil into components used for a variety of purposes. The crude petroleum is heated and the hot gases are passed into the bottom of a distillation column. As the gases move up the height of the column, the gases cool below their boiling point and condense into a liquid. The liquids are then drawn off the distilling column at specific heights to obtain fuels like gasoline, jet fuel and diesel fuel.

The liquids are processed further to make more gasoline or other finished products.

Some of the liquids undergo additional processing after the distillation process to create other products. These processes include: cracking, which is breaking down large molecules of heavy oils; reforming, which is changing molecular structures of low-quality gasoline molecules; and isomerization, which is rearranging the atoms in a molecule so that the product has the same chemical formula but has a different structure. These processes ensure that every drop of crude oil in a barrel is converted into a usable product.

The crude is heated by a furnace and is sent to a distillation tower, where it is separated by boiling point. Then the material is converted by heating, pressure or a catalyst into finished products including fuels like gasoline and diesel, and specialty products like asphalt and solvents.

Petroleum, called crude oil in the industry, is a fossil fuel found in underground reservoirs. It is classified by density, sulfur content and acidity, and those factors determine how the oil is refined. Every barrel of crude oil can be turned into several products:

At our 15 refineries our throughput capacity of crude oil and other feedstocks is 3.2 million barrels per day. Depending on the size of the refinery, from 80,000 to 300,000+ barrels of crude oil per day, per refinery, is processed to make clean transportation fuels.

Refineries are complex facilities that take crude oil and turn it into a variety of products including the fuel that powers our vehicles, to asphalt and the building blocks for many plastics used in everyday life. In order to make these products, the refinery has a variety of units, storage tanks, pipelines, water cooling towers and much more. Refineries run 24/7.

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