Sour crude oil

Last updated

Sour crude oil is crude oil containing a high amount of the impurity sulfur. It is common to find crude oil containing some impurities. When the total sulfur level in the oil is more than 0.5% (by weight), the oil is called "sour". [1]

The impurities need to be removed before this lower-quality crude can be refined into petrol, thereby increasing the cost of processing. This results in a higher-priced gasoline than that made from sweet crude oil. [1]

Current environmental regulations in the United States strictly limit the sulfur content in refined fuels such as diesel and gasoline.

The majority of the sulfur in crude oil occurs bonded to carbon atoms, with a small amount occurring as elemental sulfur in solution and as hydrogen sulfide gas. Sour oil can be toxic and corrosive, especially when the oil contains higher levels of hydrogen sulfide, which is a breathing hazard. At low concentrations the gas gives the oil the smell of rotting eggs. For safety reasons, sour crude oil needs to be stabilized by having hydrogen sulfide gas (H2S) removed from it before being transported by oil tankers. [2]

Since sour crude is more common than sweet crude in the U.S. part of the Gulf of Mexico, Platts has come out in March 2009 with a new sour crude benchmark (oil marker) called "Americas Crude Marker (ACM)". [3] Dubai Crude and Oman Crude, both sour crude oils, have been used as a benchmark (crude oil) oil marker for Middle East crude oils for some time.

The major producers of sour crude oil include:

See also

Related Research Articles

<span class="mw-page-title-main">Petroleum</span> Naturally occurring combustible liquid

Petroleum or crude oil, also referred to as simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that consist of refined crude oil.

<span class="mw-page-title-main">Oil refinery</span> Facility that processes crude oil

An oil refinery or petroleum refinery is an industrial process plant where petroleum is transformed and refined into products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefied petroleum gas and petroleum naphtha. Petrochemical feedstock like ethylene and propylene can also be produced directly by cracking crude oil without the need of using refined products of crude oil such as naphtha. The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot at or near an oil refinery for the storage of incoming crude oil feedstock as well as bulk liquid products. In 2020, the total capacity of global refineries for crude oil was about 101.2 million barrels per day.

Natural-gas condensate, also called natural gas liquids, is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields. Some gas species within the raw natural gas will condense to a liquid state if the temperature is reduced to below the hydrocarbon dew point temperature at a set pressure.

<span class="mw-page-title-main">Sweet crude oil</span> Type of petroleum

Sweet crude oil is a type of petroleum. The New York Mercantile Exchange designates petroleum with less than 0.5% sulfur as sweet.

Acid gas is a particular typology of natural gas or any other gas mixture containing significant quantities of hydrogen sulfide (H2S), carbon dioxide (CO2), or similar acidic gases. A gas is determined to be acidic or not after it is mixed with water. The pH scale ranges from 0 to 14, anything above 7 is basic while anything below 7 is acidic. Water has a neutral pH of 7 so once a gas is mixed with water, if the resulting mixture has a pH of less than 7 that means it is an acidic gas.

Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide (H2S).

Petroleum geochemistry is a branch of geochemistry which deals specifically with petroleum and its origin, generation, and accumulation, as well as its extraction, refinement, and use. Petroleum, also known as crude oil, is a solid, liquid, and/or gaesous mix of hydrocarbons. These hydrocarbons are from the burial and metamorphosis of organic matter from millions of years ago; the organic matter is from marine animals, plants, and algae. Petroleum is extracted from the Earth, refined, and used as an energy source.

<span class="mw-page-title-main">Catalytic reforming</span> Chemical process used in oil refining

Catalytic reforming is a chemical process used to convert petroleum refinery naphthas distilled from crude oil into high-octane liquid products called reformates, which are premium blending stocks for high-octane gasoline. The process converts low-octane linear hydrocarbons (paraffins) into branched alkanes (isoparaffins) and cyclic naphthenes, which are then partially dehydrogenated to produce high-octane aromatic hydrocarbons. The dehydrogenation also produces significant amounts of byproduct hydrogen gas, which is fed into other refinery processes such as hydrocracking. A side reaction is hydrogenolysis, which produces light hydrocarbons of lower value, such as methane, ethane, propane and butanes.

The oil and gas industry is usually divided into three major sectors: upstream, midstream, and downstream. The downstream sector is the refining of petroleum crude oil and the processing and purifying of raw natural gas, as well as the marketing and distribution of products derived from crude oil and natural gas. The downstream sector reaches consumers through products such as gasoline or petrol, kerosene, jet fuel, diesel oil, heating oil, fuel oils, lubricants, waxes, asphalt, natural gas, and liquefied petroleum gas (LPG) as well as naphtha and hundreds of petrochemicals.

Light crude oil is liquid petroleum that has a low density and flows freely at room temperature. It has a low viscosity, low specific gravity and high API gravity due to the presence of a high proportion of light hydrocarbon fractions. It generally has a low wax content. Light crude oil receives a higher price than heavy crude oil on commodity markets because it produces a higher percentage of gasoline and diesel fuel when converted into products by an oil refinery.

<span class="mw-page-title-main">Fluid catalytic cracking</span> Petroleum conversion process

Fluid catalytic cracking (FCC) is the conversion process used in petroleum refineries to convert the high-boiling point, high-molecular weight hydrocarbon fractions of petroleum into gasoline, alkene gases, and other petroleum products. The cracking of petroleum hydrocarbons was originally done by thermal cracking, now virtually replaced by catalytic cracking, which yields greater volumes of high octane rating gasoline; and produces by-product gases, with more carbon-carbon double bonds, that are of greater economic value than the gases produced by thermal cracking.

<span class="mw-page-title-main">Hydrodesulfurization</span> Chemical process used to remove sulfur in natural gas and oil refining

Hydrodesulfurization (HDS), also called hydrotreatment or hydrotreating, is a catalytic chemical process widely used to remove sulfur (S) from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils. The purpose of removing the sulfur, and creating products such as ultra-low-sulfur diesel, is to reduce the sulfur dioxide emissions that result from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, gas or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion.

<span class="mw-page-title-main">Benchmark (crude oil)</span> Reference price for trading of an oil commodity

A benchmark crude or marker crude is a crude oil that serves as a reference price for buyers and sellers of crude oil. There are three primary benchmarks, West Texas Intermediate (WTI), Brent Blend, and Dubai Crude. Other well-known blends include the OPEC Reference Basket used by OPEC, Tapis Crude which is traded in Singapore, Western Canadian Select used in Canada, Bonny Light used in Nigeria, Urals oil used in Russia and Mexico's Isthmus. Energy Intelligence Group publishes a handbook which identified 195 major crude streams or blends in its 2011 edition.

<span class="mw-page-title-main">Natural-gas processing</span> Industrial processes designed to purify raw natural gas

Natural-gas processing is a range of industrial processes designed to purify raw natural gas by removing contaminants such as solids, water, carbon dioxide (CO2), hydrogen sulfide (H2S), mercury and higher molecular mass hydrocarbons (condensate) to produce pipeline quality dry natural gas for pipeline distribution and final use. Some of the substances which contaminate natural gas have economic value and are further processed or sold. Hydrocarbons that are liquid at ambient conditions: temperature and pressure (i.e., pentane and heavier) are called natural-gas condensate (sometimes also called natural gasoline or simply condensate).

Selexol is the trade name for an acid gas removal solvent that can separate acid gases such as hydrogen sulfide and carbon dioxide from feed gas streams such as synthesis gas produced by gasification of coal, coke, or heavy hydrocarbon oils. By doing so, the feed gas is made more suitable for combustion and/or further processing. It is made up of dimethyl ethers of polyethylene glycol.

<span class="mw-page-title-main">History of the petroleum industry in Canada (natural gas)</span>

Natural gas has been used almost as long as crude oil in Canada, but its commercial development was not as rapid. This is because of special properties of this energy commodity: it is a gas, and it frequently contains impurities. The technical challenges involved to first process and then pipe it to market are therefore considerable. Furthermore, the costs of pipeline building make the whole enterprise capital intensive, requiring both money and engineering expertise, and large enough markets to make the business profitable.

Tapis crude is a Malaysian crude oil used as a pricing benchmark in Singapore. Tapis is very light, with an API gravity of 43°-45°, and very sweet, with only about 0.04% sulfur. While it is not traded on a market like Brent Crude or West Texas Intermediate (WTI), it is often used as an oil marker or price referencing indicator for Asia and Australia.

<span class="mw-page-title-main">Petroleum refining processes</span> Methods of transforming crude oil

Petroleum refining processes are the chemical engineering processes and other facilities used in petroleum 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.

Base oils are used to manufacture products including lubricating greases, motor oil and metal processing fluids. Different products require different compositions and properties in the oil. One of the most important factors is the liquid’s viscosity at various temperatures. Whether or not a crude oil is suitable to be made into a base oil is determined by the concentration of base oil molecules as well as how easily these can be extracted.

Sulfur production in the United States was 9.04 million metric tons of sulfur content in 2014, all of it recovered as a byproduct, from oil refineries, natural gas processing plants, and metal smelters. The United States was second in the world in sulfur production in 2014, behind China. The sulfur recovered was marketed in the forms of native (elemental) sulfur, and sulfuric acid. Total value was US$927 million in 2014.

References

  1. 1 2 3 "Heavy Sour Crude Oil, A Challenge For Refiners". Archived from the original on 2008-11-21.
  2. "Sweetening Up the Crude".
  3. Americas Crude Marker (ACM)