HistoryThe Chinese were among the first civilizations to refine oil. As early as the first century, the Chinese were refining crude oil for use as an energy source. Between 512 and 518, in the late Northern Wei Dynasty, the Chinese geographer, writer and politician Li Daoyuan introduced the process of refining oil into various lubricants in his famous work ''Commentary on the Water Classic''. Crude oil was often distilled by Alchemy and chemistry in medieval Islam, Arab chemists, with clear descriptions given in Arabic handbooks such as those of Muhammad ibn Zakarīya Rāzi (854–925). The streets of Baghdad were paved with tar, derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in the area around modern Baku, Azerbaijan. These fields were described by the Islamic geography, Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. Alchemy and chemistry in Islam, Arab and Persian chemists also distilled crude oil in order to produce Flammability, flammable products for military purposes. Through Al-Andalus, Islamic Spain, distillation became available in Western Europe by the 12th century. In the Northern Song Dynasty (960–1127), a workshop called the "Fierce Oil Workshop", was established in the city of Kaifeng to produce refined oil for the Song military as a weapon. The troops would then fill iron cans with refined oil and throw them toward the enemy troops, causing a fire – effectively the world's first "Incendiary device, fire bomb". The workshop was one of the world's earliest oil refining factories where thousands of people worked to produce Chinese oil-powered weaponry. Prior to the nineteenth century, petroleum was known and utilized in various fashions in Babylon, Egypt, China, Philippines, Rome and Azerbaijan. However, 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 Łukasiewicz began producing kerosene from hand-dug oil wells near the town of Krosno, Poland. The world's first systematic petroleum refinery was built in Ploiești, Romania in 1856 using the abundant oil available in Romania. In North America, the first oil well was drilled in 1858 by James Miller Williams in Oil Springs, Ontario, Oil Springs, Ontario, Canada. In the United States, the petroleum industry began in 1859 when Edwin Drake found oil near Titusville, Pennsylvania, Titusville, Pennsylvania. 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. Samuel Kier established America's first oil refinery in Pittsburgh on Seventh avenue near Grant Street, in 1853.The American Manufacturer and Iron Worl
Oil refining in the United StatesIn the 19th century, refineries in the U.S. processed crude oil primarily to recover the kerosene. There was no market for the more volatile fraction, including gasoline, which was considered waste and was often dumped directly into the nearest river. The invention of the automobile shifted the demand to gasoline and diesel, which remain the primary refined products today. Today, national and state legislation require refineries to meet stringent air and water cleanliness standards. In fact, oil companies in the U.S. perceive obtaining a permit to build a modern refinery to be so difficult and costly that no new refineries were built (though many have been expanded) in the U.S. from 1976 until 2014 when the small Dakota Prairie Refinery in North Dakota began operation. More than half the refineries that existed in 1981 are now closed due to low utilization rates and accelerating mergers. As a result of these closures total US refinery capacity fell between 1981 and 1995, though the operating capacity stayed fairly constant in that time period at around . Increases in facility size and improvements in efficiencies have offset much of the lost physical capacity of the industry. In 1982 (the earliest data provided), the United States operated 301 refineries with a combined capacity of of crude oil each calendar day. In 2010, there were 149 operable U.S. refineries with a combined capacity of per calendar day. By 2014 the number of refinery had reduced to 140 but the total capacity increased to per calendar day. Indeed, in order to reduce operating costs and depreciation, refining is operated in fewer sites but of bigger capacity. In 2009 through 2010, as revenue streams in the oil business dried up and profitability of oil refineries fell due to lower demand for product and high reserves of supply preceding the Late-2000s recession, economic recession, oil companies began to close or sell the less profitable refineries.
OperationRaw or unprocessed crude oil is not generally useful in industrial applications, although "light, sweet" (low viscosity, low sulfur) crude oil has been used directly as a burner fuel to produce steam for the propulsion of seagoing vessels. The lighter elements, however, form explosive vapors in the fuel tanks and are therefore hazardous, especially in warships. Instead, the hundreds of different hydrocarbon molecules in crude oil are separated in a refinery into components that can be used as fuels, lubricants, and feedstocks in petrochemical processes that manufacture such products as plastics, detergents, solvents, elastomers, and fibers such as nylon and polyesters. Petroleum fossil fuels are burned in internal combustion engines to provide power for ships, automobiles, aircraft engines, lawn mowers, dirt bikes, and other machines. Different boiling points allow the hydrocarbons to be separated by distillation. Since the lighter liquid products are in great demand for use in internal combustion engines, a modern refinery will convert heavy hydrocarbons and lighter gaseous elements into these higher-value products. Oil can be used in a variety of ways because it contains hydrocarbons of varying molecular masses, forms and lengths such as Alkane, paraffins, aromatics, naphthenes (or cycloalkanes), alkenes, dienes, and alkynes. While the molecules in crude oil include different atoms such as sulfur and nitrogen, the hydrocarbons are the most common form of molecules, which are molecules of varying lengths and complexity made of hydrogen and carbon atoms, and a small number of oxygen atoms. The differences in the structure of these molecules account for their varying Physical property, physical and Chemical property, chemical properties, and it is this variety that makes crude oil useful in a broad range of several applications. Once separated and purified of any contaminants and impurities, the fuel or lubricant can be sold without further processing. Smaller molecules such as isobutane and propylene or butylenes can be recombined to meet specific octane rating, octane requirements by processes such as alkylation, or more commonly, Dimer (chemistry), dimerization. The octane grade of gasoline can also be improved by catalytic reforming, which involves removing hydrogen from hydrocarbons producing compounds with higher octane ratings such as aromatics. Intermediate products such as gasoils can even be reprocessed to break a heavy, long-chained oil into a lighter short-chained one, by various forms of cracking (chemistry), cracking such as fluid catalytic cracking, thermal cracking, and hydrocracking. The final step in gasoline production is the blending of fuels with different octane ratings, vapor pressures, and other properties to meet product specifications. Another method for reprocessing and upgrading these intermediate products (residual oils) uses a wikt:devolatilization, devolatilization process to separate usable oil from the waste asphaltene material. Oil refineries are large-scale plants, processing about a hundred thousand to several hundred thousand Barrel (volume), barrels of crude oil a day. Because of the high capacity, many of the units operate Continuous production, continuously, as opposed to processing in Batch production, batches, at steady state or nearly steady state for months to years. The high capacity also makes process optimization and advanced process control very desirable.
Major productsPetroleum products are materials derived from crude oil (petroleum) as it is processed in oil refineries. The majority of petroleum is converted to petroleum products, which includes several classes of fuels. Oil refineries also produce various intermediate products such as hydrogen, light hydrocarbons, reformate and pyrolysis gasoline. These are not usually transported but instead are blended or processed further on-site. Chemical plants are thus often adjacent to oil refineries or a number of further chemical processes are integrated into it. For example, light hydrocarbons are Steam cracking, steam-cracked in an ethylene plant, and the produced ethylene is polymerized to produce polyethene. Because technical reasons and environment protection demand a very low sulfur content in all but the heaviest products, it is transformed to hydrogen sulfide via catalytic hydrodesulfurization and removed from the product stream via amine gas treating. Using the Claus process, hydrogen sulfide is afterward transformed to elementary sulfur to be sold to the chemical industry. The rather large heat energy freed by this process is directly used in the other parts of the refinery. Often an electrical power plant is combined into the whole refinery process to take up the excess heat. According to the composition of the crude oil and depending on the demands of the market, refineries can produce different shares of petroleum products. The largest share of oil products is used as "energy carriers", i.e. various grades of fuel oil and gasoline. These fuels include or can be blended to give gasoline, jet fuel, diesel fuel, heating oil, and heavier fuel oils. Heavier (less Volatility (chemistry), volatile) fractions can also be used to produce asphalt, tar, paraffin wax, Lubricant, lubricating and other heavy oils. Refineries also produce other chemicals, some of which are used in chemical processes to produce plastics and other useful materials. Since petroleum often contains a few percent sulfur-containing molecules, elemental sulfur is also often produced as a petroleum product. Carbon, in the form of petroleum coke, and hydrogen may also be produced as petroleum products. The hydrogen produced is often used as an intermediate product for other oil refinery processes such as hydrocracking and hydrodesulfurization. Petroleum products are usually grouped into four categories: light distillates (LPG, gasoline, naphtha), middle distillates (kerosene, jet fuel, diesel), heavy distillates, and residuum (heavy fuel oil, lubricating oils, wax, asphalt). These require blending various feedstocks, mixing appropriate additives, providing short-term storage, and preparation for bulk loading to trucks, barges, product ships, and railcars. This classification is based on the way crude oil is distilled and separated into fractions. *Gaseous fuel such as liquified petroleum gas and propane, stored and shipped in liquid form under pressure. *Lubricants (produces light machine oils, motor oils, and Grease (lubricant), greases, adding viscosity stabilizers as required), usually shipped in bulk to an offsite packaging plant. *Paraffin wax, used in the candle industry, among others. May be shipped in bulk to a site to prepare as packaged blocks. Used for wax emulsions, candles, matches, rust protection, vapor barriers, construction board, and packaging of frozen foods. *Sulfur (or sulfuric acid), byproducts of sulfur removal from petroleum which may have up to a couple of percent sulfur as organic sulfur-containing compounds. Sulfur and sulfuric acid are useful industrial materials. Sulfuric acid is usually prepared and shipped as the acid precursor oleum. *Bulk tar shipping for offsite unit packaging for use in tar-and-gravel roofing. *Asphalt used as a binder for gravel to form asphalt concrete, which is used for paving roads, lots, etc. An asphalt unit prepares bulk asphalt for shipment. *Petroleum coke, used in specialty carbon products like electrodes or as solid fuel. *Petrochemicals are organic compounds that are the ingredients for the chemical industry, ranging from polymers and pharmaceuticals, including ethylene and benzene-toluene-xylenes ("BTX") which are often sent to petrochemical plants for further processing in a variety of ways. The petrochemicals may be olefins or their precursors, or various types of aromatic petrochemicals. *Gasoline *Naphtha *Kerosene and related jet fuel, jet aircraft fuels *Diesel fuel and fuel oils *Heat *Electricity Over 6,000 items are made from petroleum waste by-products including: fertilizer, floor coverings, perfume, insecticide, petroleum jelly, soap, vitamin capsules. See link to partial list of 144 by-products listed by Ranken Energy.
Chemical processes found in a refinery*Desalter unit washes out salt from the crude oil before it enters the atmospheric distillation unit. *Atmospheric distillation of crude oil, Crude oil distillation unit distills the incoming crude oil into various fractions for further processing in other units. See continuous distillation. *Vacuum Distillation, Vacuum distillation further distills the residue oil from the bottom of the crude oil distillation unit. The vacuum distillation is performed at a pressure well below atmospheric pressure. *Naphtha hydrotreater unit uses hydrogen to desulfurize naphtha from atmospheric distillation. Naphtha must be desulfurized before sending it to a catalytic reformer unit. *Catalytic reforming, Catalytic reformer converts the desulfurized naphtha molecules into higher-octane molecules to produce reformate (reformer product). The reformate has higher content of aromatics and cyclic hydrocarbons which is a component of the end-product gasoline or petrol. An important byproduct of a reformer is hydrogen released during the catalyst reaction. The hydrogen is used either in the hydrotreaters or the hydrocracker. *Hydrodesulfurization, Distillate hydrotreater desulfurizes distillates (such as diesel) after atmospheric distillation. Uses hydrogen to desulfurize the Petroleum naphtha, naphtha fraction from the crude oil distillation or other units within the refinery. *Fluid catalytic cracking, Fluid catalytic cracker (FCC) upgrades the heavier, higher-boiling fractions from the crude oil distillation by converting them into lighter and lower boiling, more valuable products. *Cracking (chemistry), Hydrocracker uses hydrogen to upgrade heavy residual oils from the vacuum distillation unit by thermally cracking them into lighter, more valuable reduced viscosity products. *Merox desulfurize LPG, kerosene or jet fuel by oxidizing mercaptans to organic disulfides. *Alternative processes for removing mercaptans are known, e.g. doctor sweetening process and caustic washing. *Coker unit, Coking units (delayed coker, fluid coker, and flexicoker) process very heavy residual oils into gasoline and diesel fuel, leaving petroleum coke as a residual product. *Alkylation unit uses sulfuric acid or hydrofluoric acid to produce high-octane components for gasoline blending. The "alky" unit converts light end isobutane and butylenes from the FCC process into ''alkylate'', a very high-octane component of the end-product gasoline or petrol. *Dimer (chemistry), Dimerization unit converts olefins into higher-octane gasoline blending components. For example, butenes can be dimerized into isooctene which may subsequently be hydrogenated to form isooctane. There are also other uses for dimerization. Gasoline produced through dimerization is highly unsaturated and very reactive. It tends spontaneously to form gums. For this reason, the effluent from the dimerization needs to be blended into the finished gasoline pool immediately or hydrogenated. *Isomerization converts linear molecules such as normal pentane to higher-octane branched molecules for blending into gasoline or feed to alkylation units. Also used to convert linear normal butane into isobutane for use in the alkylation unit. *Steam reforming converts natural gas into hydrogen for the hydrotreaters and/or the hydrocracker. *Liquified gas storage vessels store propane and similar gaseous fuels at pressure sufficient to maintain them in liquid form. These are usually spherical vessels or "bullets" (i.e., horizontal vessels with rounded ends). *Amine gas treater, Claus process, Claus unit, and tail gas treatment convert hydrogen sulfide from hydrodesulfurization into elemental sulfur. The large majority of the 64,000,000 metric tons of sulfur produced worldwide in 2005 was byproduct sulfur from petroleum refining and natural gas processing plants. *Claus process, Sour water stripper uses steam to remove hydrogen sulfide gas from various wastewater streams for subsequent conversion into end-product sulfur in the Claus unit. *Cooling towers circulate cooling water, Boiler, boiler plants generates steam for Water-tube boiler, steam generators, and instrument air systems include pneumatically operated control valves and an electrical substation. *Wastewater collection and treating systems consist of API separators, Dissolved air flotation, dissolved air flotation (DAF) units and further treatment units such as an activated sludge biotreater to make water suitable for reuse or for disposal. *Solvent refining uses solvent such as cresol or furfural to remove unwanted, mainly aromatics from lubricating oil stock or diesel stock. *Solvent dewaxing removes the heavy waxy constituents petrolatum from vacuum distillation products. * Storage tanks for storing crude oil and finished products, usually vertical, cylindrical vessels with some sort of vapor emission control and surrounded by an earthen berm to contain spills.
Flow diagram of typical refineryThe image below is a schematic Process flow diagram, flow diagram of a typical oil refinery that depicts the various Chemical plant#Chemical processes, unit 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. There are many process configurations other than that depicted above. For example, the vacuum distillation unit may also produce fractions that can be refined into end products such as spindle oil used in the textile industry, light machine oil, motor oil, and various waxes.
The crude oil distillation unitThe 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 is 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. 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.
Location of petroleum refineriesA party searching for a site to construct a refinery or a chemical plant needs to consider the following issues: *The site has to be reasonably far from residential areas. *Infrastructure should be available for the supply of raw materials and shipment of products to markets. *Energy to operate the plant should be available. *Facilities should be available for waste disposal. Factors affecting site selection for oil refinery: *Availability of land *Conditions of traffic and transportation *Conditions of utilities - power supply, water supply *Availability of labours and resources Refineries that use a large amount of steam and cooling water need to have an abundant source of water. Oil refineries, therefore, are often located nearby navigable rivers or on a seashore, nearby a port. Such location also gives access to transportation by river or by sea. The advantages of transporting crude oil by pipeline are evident, and oil companies often transport a large volume of fuel to distribution terminals by pipeline. A pipeline may not be practical for products with small output, and railcars, road tankers, and barges are used. Petrochemical plants and solvent manufacturing (fine fractionating) plants need spaces for further processing of a large volume of refinery products, or to mix chemical additives with a product at source rather than at blending terminals.
Safety and environment. The refining process releases a number of different chemicals into the Earth's atmosphere, atmosphere (see AP 42 Compilation of Air Pollutant Emission Factors) and a notable odor normally accompanies the presence of a refinery. Aside from air pollution impacts there are also wastewater concerns, risks of industrial accidents such as fire and explosion, and noise health effects due to industrial noise. Many governments worldwide have mandated restrictions on contaminants that refineries release, and most refineries have installed the equipment needed to comply with the requirements of the pertinent environmental protection regulatory agencies. In the United States, there is strong pressure to prevent the development of new refineries, and no major refinery has been built in the country since Marathon Petroleum Company, Marathon's Garyville, Louisiana facility in 1976. However, many existing refineries have been expanded during that time. Environmental restrictions and pressure to prevent the construction of new refineries may have also contributed to rising fuel prices in the United States. Additionally, many refineries (more than 100 since the 1980s) have closed due to obsolescence and/or merger activity within the industry itself. Environmental and safety concerns mean that oil refineries are sometimes located some distance away from major urban areas. Nevertheless, there are many instances where refinery operations are close to populated areas and pose health risks. In California's Contra Costa County and Solano County, a shoreline necklace of refineries, built in the early 20th century before this area was populated, and associated chemical plants are Housing Discrimination in the East Bay, adjacent to urban areas in Chevron Richmond Refinery, Richmond, Martinez, California, Martinez, Pacheco, California, Pacheco, Concord, California, Concord, Pittsburg, California, Pittsburg, Vallejo, California, Vallejo and Benicia, California, Benicia, with occasional accidental events that require "shelter in place" orders to the adjacent populations. A number of refineries are located in Sherwood Park, Alberta, directly adjacent to the City of Edmonton. The Edmonton metro area has a population of over 1,000,000 residents. National Institute for Occupational Safety and Health, NIOSH criteria for Occupational exposure limit, occupational exposure to refined petroleum solvents have been available since 1977.
BackgroundModern Petroleum refining processes, petroleum refining involves a complicated system of interrelated chemical reactions that produce a wide variety of petroleum-based products. Many of these reactions require precise temperature and pressure parameters. The equipment and monitoring required to ensure the proper progression of these processes is complex, and has evolved through the advancement of the scientific field of petroleum engineering. The wide array of high pressure and/or high temperature reactions, along with the necessary chemical additives or extracted contaminants, produces an astonishing number of potential health hazards to the oil refinery worker. Through the advancement of technical chemical and petroleum engineering, the vast majority of these processes are automated and enclosed, thus greatly reducing the potential health impact to workers. However, depending on the specific process in which a worker is engaged, as well as the particular method employed by the refinery in which he/she works, significant health hazards remain. Although occupational injuries in the United States were not routinely tracked and reported at the time, reports of the health impacts of working in an oil refinery can be found as early as the 1800s. For instance, an explosion in a Chicago refinery killed 20 workers in 1890. Since then, numerous fires, explosions, and other significant events have from time to time drawn the public's attention to the health of oil refinery workers. Such events continue in the 21st century, with explosions reported in refineries in Wisconsin and Germany in 2018. However, there are many less visible hazards that endanger oil refinery workers.
Chemical exposuresGiven the highly automated and technically advanced nature of modern petroleum refineries, nearly all processes are contained within engineering controls and represent a substantially decreased risk of exposure to workers compared to earlier times. However, certain situations or work tasks may subvert these safety mechanisms, and expose workers to a number of chemical (see table above) or physical (described below) hazards. Examples of these scenarios include: * System failures (leaks, explosions, etc.). * Standard inspection, product sampling, process turnaround, or equipment maintenance/cleaning activities. Interestingly, even though petroleum refineries utilize and produce chemicals that are known carcinogens, the literature on cancer rates among refinery workers is mixed. For example, benzene has been shown to have a relationship with leukemia, however studies examining benzene exposure and resultant leukemia specifically in the context of oil refinery workers have come to opposing conclusions. Asbestos-related mesothelioma is another particular cancer-carcinogen relationship that has been investigated in the context of oil refinery workers. To date, this work has shown a marginally significant link to refinery employment and mesothelioma. Notably, a meta-analysis which included data on more than 350,000 refinery workers failed to find any statistically significant excess rates of cancer mortality, except for a marginally significant increase in melanoma deaths. An additional US-based study included a follow-up period of 50 years among over 17,000 workers. This study concluded that there was no excess mortality among this cohort as a result of employment. BTX (chemistry), BTX stands for benzene, toluene, xylene. This is a group of common volatile organic compounds (VOCs) that are found in the oil refinery environment, and serve as a paradigm for more in depth discussion of occupational exposure limits, chemical exposure and surveillance among refinery workers. The most important route of exposure for BTX chemicals is inhalation due to the low boiling point of these chemicals. The majority of the gaseous production of BTX occurs during tank cleaning and fuel transfer, which causes offgassing of these chemicals into the air. Exposure can also occur through ingestion via contaminated water, but this is unlikely in an occupational setting. Dermal exposure and absorption is also possible, but is again less likely in an occupational setting where appropriate personal protective equipment is in place. In the United States, the Occupational Safety and Health Administration (OSHA), National Institute for Occupational Safety and Health (NIOSH), and American Conference of Governmental Industrial Hygienists (ACGIH) have all established occupational exposure limits (OELs) for many of the chemicals above that workers may be exposed to in petroleum refineries. Benzene, in particular, has multiple biomarkers that can be measured to determine exposure. Benzene itself can be measured in the breath, blood, and urine, and metabolites such as phenol, Muconic acid, ''t'',''t''-muconic acid (''t'',''t''MA) and S-phenylmercapturic acid (''s''PMA) can be measured in urine. In addition to monitoring the exposure levels via these biomarkers, employers are required by OSHA to perform regular blood tests on workers to test for early signs of some of the feared hematologic outcomes, of which the most widely recognized is leukemia. Required testing includes Complete blood count, complete blood count with cell differentials and peripheral blood smear "on a regular basis". The utility of these tests is supported by formal scientific studies.
Potential Chemical Exposure by Process
Physical hazardsWorkers are at risk of physical injuries due to a large number of high-powered machines in the relatively close proximity of the oil refinery. The high pressure required for many of the chemical reactions also presents the possibility of localized system failures resulting in blunt or penetrating trauma from exploding system components. Heat is also a hazard. The temperature required for the proper progression of certain reactions in the refining process can reach . As with chemicals, the operating system is designed to safely contain this hazard without injury to the worker. However, in system failures, this is a potent threat to workers’ health. Concerns include both direct injury through a Heat illness, heat illness or injury, as well as the potential for devastating burns should the worker come in contact with super-heated reagents/equipment. Noise is another hazard. Refineries can be very loud environments, and have previously been shown to be associated with hearing loss among workers. The interior environment of an oil refinery can reach levels in excess of 90 Decibel, dB. In the United States, an average of 90 dB is the permissible exposure limit (PEL) for an 8-hour work-day. Noise exposures that average greater than 85 dB over an 8-hour require a hearing conservation program to regularly evaluate workers' hearing and to promote its protection. Regular evaluation of workers’ auditory capacity and faithful use of Ear protection, properly vetted hearing protection are essential parts of such programs. While not specific to the industry, oil refinery workers may also be at risk for hazards such as Traffic collision, vehicle-related accidents, machinery-associated injuries, work in a confined space, explosions/fires, ergonomic hazards, Shift work sleep disorder, shift-work related sleep disorders, and falls.
Hazard controlsThe theory of Hierarchy of hazard controls, hierarchy of controls can be applied to petroleum refineries and their efforts to ensure worker safety. Hazard elimination, Elimination and Hazard substitution, substitution are unlikely in petroleum refineries, as many of the raw materials, waste products, and finished products are hazardous in one form or another (e.g. flammable, carcinogenic). Examples of engineering controls include a Fire detection system, fire detection/extinguishing system, pressure/chemical sensors to detect/predict loss of structural integrity, and adequate maintenance of piping to prevent hydrocarbon-induced corrosion (leading to structural failure). Other examples employed in petroleum refineries include the post-construction protection of steel components with vermiculite to improve heat/fire resistance. Compartmentalization (fire protection), Compartmentalization can help to prevent a fire or other systems failure from spreading to affect other areas of the structure, and may help prevent dangerous reactions by keeping different chemicals separate from one another until they can be safely combined in the proper environment. Administrative controls include careful planning and oversight of the refinery cleaning, maintenance, and turnaround processes. These occur when many of the engineering controls are shut down or suppressed and may be especially dangerous to workers. Detailed coordination is necessary to ensure that maintenance of one part of the facility will not cause dangerous exposures to those performing the maintenance, or to workers in other areas of the plant. Due to the highly flammable nature of many of the involved chemicals, smoking areas are tightly controlled and carefully placed. Personal protective equipment (PPE) may be necessary depending on the specific chemical being processed or produced. Particular care is needed during sampling of the partially-completed product, tank cleaning, and other high-risk tasks as mentioned above. Such activities may require the use of impervious outerwear, acid hood, disposable coveralls, etc. More generally, all personnel in operating areas should use appropriate Ear protection, hearing and Safety goggles, vision protection, avoid clothes made of flammable material (nylon, Dacron, Acrylic fiber, acrylic, or blends), and full-length pants and sleeves.
United StatesWorker health and safety in oil refineries is closely monitored at a national level by both the Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH). In addition to US Federal Government, federal monitoring, California's California Division of Occupational Safety and Health, CalOSHA has been particularly active in protecting worker health in the industry, and adopted a policy in 2017 that requires petroleum refineries to perform a "Hierarchy of Hazard Controls Analysis" (see above "Hazard controls" section) for each process safety hazard. Safety regulations have resulted in a below-average injury rate for refining industry workers. In a 2018 report by the US Bureau of Labor Statistics, they indicate that petroleum refinery workers have a significantly lower rate of occupational injury (0.4 OSHA-recordable cases per 100 full-time workers) than all industries (3.1 cases), oil and gas extraction (0.8 cases), and petroleum manufacturing in general (1.3 cases). Below is a list of the most common regulations referenced in petroleum refinery safety citations issued by OSHA: * Flammable and Combustible Liquids () * The Hazard Communication (HazCom) standard () * Permit-Required Confined Spaces () * Hazardous (Classified) Locations () * The Personal Protective Equipment (PPE) standard () * The Control of Hazardous Energy (Lockout/Tagout) standard ()
Corrosionin Bratislava. File:Bidboland gas refinery.jpg, upright=1.35, Oil refinery in Iran. Corrosion of metallic components is a major factor of inefficiency in the refining process. Because it leads to equipment failure, it is a primary driver for the refinery maintenance schedule. Corrosion-related direct costs in the U.S. petroleum industry as of 1996 were estimated at US$3.7 billion.Corrosion Costs and Preventive Strategies in the United States
See also*Acid gas *H-Bio *AP 42 Compilation of Air Pollutant Emission Factors *API oil-water separator *Biorefinery *Ethanol fuel *Butanol fuel *Gas flare *Industrial wastewater treatment *K factor crude oil refining *List of oil refineries *Natural-gas processing