Oil refinery

• 1. Introduction

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  Oil refineries sit at the center of the modern world, yet most people have never given one a second thought. In 2020, global refineries processed about 101.2 million barrels of crude oil every single day. That number is almost impossible to picture. But consider that the gasoline in your car, the jet fuel lifting your plane, the asphalt under your tires, and the nylon in your jacket all began as crude oil flowing into a plant like this. What turns a thick, dark liquid pulled from the earth into thousands of distinct products? And how did humanity figure out that it could? The answers stretch back further than most people expect, to ancient China and medieval Baghdad, and they run straight through some of the most consequential decisions of the 20th century.

• 2. Ancient Roots

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  As early as the 1st century, Chinese civilization was refining crude oil for use as an energy source. The practice was not casual experimentation. Between 512 and 518, during the late Northern Wei dynasty, the geographer and writer Li Daoyuan described the process in his work Commentary on the Water Classic, documenting how oil could be refined into various lubricants.

  Persian chemists were also at work on the problem. Muhammad ibn Zakariya Razi, who lived roughly from 865 to 925, left clear descriptions of crude oil distillation in his handbooks. The streets of Baghdad were paved with tar derived from petroleum that seeped up naturally in the region. Oil fields near what is now Baku, Azerbaijan were being exploited by the 9th century, and the Arab geographer Abu al-Hasan Ali al-Masudi described them in the 10th century. When Marco Polo passed through in the 13th century, he reported the output of those wells as hundreds of shiploads.

  Arab and Persian chemists also refined oil for military applications, producing flammable products used in warfare. Through Islamic Spain, distillation techniques reached Western Europe by the 12th century. In the Northern Song dynasty, which ran from 960 to 1127, a workshop called the Fierce Oil Workshop was established in Kaifeng specifically to produce refined oil as a weapon for the Song military. Troops filled iron cans with the refined oil and threw them at enemy forces, creating what the source describes as effectively the world's first fire bomb. Thousands of people worked in that workshop, making it one of the earliest industrial-scale oil refining operations on record.

• 3. The Modern Industry Begins

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  The year 1846 marks the conventional starting point of the modern petroleum industry, when Abraham Gesner of Nova Scotia devised a process for producing kerosene from coal. Just eight years later, in 1854, Ignacy Lukasiewicz began producing kerosene from hand-dug oil wells near the town of Krosno, Poland. That same year, Lukasiewicz established an oil refinery in Jaslo, then part of the Austro-Hungarian Empire.

  In North America, James Miller Williams drilled the first oil well in Oil Springs, Ontario, Canada in 1858. Edwin Drake found oil near Titusville, Pennsylvania the following year, and the American petroleum industry was born. In the 19th century, the primary product refineries chased was kerosene for oil lamps. Gasoline, the lighter fraction, was considered waste and was often dumped directly into the nearest river.

  Samuel Kier established America's first oil refinery in Pittsburgh on Seventh Avenue near Grant Street in 1853. The first large refinery opened at Ploiesti, Romania in 1856-1857. Romania was subsequently registered as the first country in world oil production statistics, according to the Academy of World Records. Early oil finds in Ontario and Pennsylvania were soon overshadowed by major booms in Oklahoma, Texas, and California.

  The invention of the internal combustion engine changed everything. The automobile created mass demand for gasoline, turning what had been a waste product into the most sought-after fraction of crude oil and driving rapid growth across the entire petroleum industry in the early 20th century.

• 4. The Edeleanu Breakthrough

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  Ploiesti, Romania produced more than just the world's first large refinery. In 1908, exactly 51 years after that refinery opened, a Romanian chemist named Lazar Edeleanu invented, patented, and tested on an industrial scale the first modern method of liquid extraction for refining crude oil. Edeleanu is a remarkable figure. He had earned his PhD in 1887 by discovering amphetamine, and he brought that same rigorous chemical thinking to the problem of refining.

  The Edeleanu process improved refining efficiency beyond what pure fractional distillation could achieve and opened the door to a massive expansion of refining capacity worldwide. The process spread to France, Germany, and the United States within decades. In 1910, Edeleanu founded a company in Germany called Allgemeine Gesellschaft fur Chemische Industrie, which later changed its name to Edeleanu GmbH in 1930 following the success of his name in the industry.

  During the Nazi period, the company was acquired by Deutsche Erdol-AG, and Edeleanu, who was of Jewish origin, returned to Romania. After the war, successor companies carried the trademark forward, eventually becoming EDL within the Pörner Group. The Ploiesti refineries themselves had a darker fate during the war years. After being seized by Nazi Germany, they were bombed by Allied forces in the 1943 Operation Tidal Wave during the Oil Campaign of World War II.

• 5. How a Refinery Works

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  Crude oil arrives at a refinery as a mixture of hundreds of different hydrocarbon molecules, along with impurities including sulfur and nitrogen. The first processing unit in virtually every refinery is the crude oil distillation unit, which operates at slightly above atmospheric pressure and is often called the atmospheric distillation unit for that reason.

  Incoming crude is preheated by exchanging heat with already-distilled hot fractions, then desalted to remove inorganic salts, primarily sodium chloride. After further heating, it passes through a fuel-fired furnace to reach about 398 degrees Celsius before entering the bottom of the distillation column. Different molecules boil at different temperatures, which allows them to be separated into distinct fractions: the overhead fraction is naphtha, and sidecuts pulled from various heights of the column yield kerosene, light gas oil, and heavy gas oil.

  Those fractions are only the beginning. Heavy hydrocarbons can be broken into lighter, more valuable ones through processes called cracking, including fluid catalytic cracking, thermal cracking, and hydrocracking. Octane ratings can be improved by catalytic reforming, which removes hydrogen from hydrocarbons to produce higher-octane aromatics. Smaller molecules like isobutane can be recombined through alkylation to meet specific fuel requirements. The final gasoline product is itself a blend of streams with different octane ratings and vapor pressures, carefully combined to meet product specifications.

  Sulfur, which crude oil often contains at a few percent, is extracted through catalytic hydrodesulfurization, converted to hydrogen sulfide, and then transformed into elemental sulfur via the Claus process. That sulfur is sold to the chemical industry, and the heat released in the process is reused elsewhere in the refinery. Over 6,000 items are made from petroleum waste by-products, including fertilizer, floor coverings, perfume, insecticide, petroleum jelly, soap, and vitamin capsules.

• 6. The American Refining Landscape

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  In 1982, the United States operated 301 refineries with a combined capacity of 17.9 million barrels of crude oil per calendar day. By 2010, that number had fallen to 149 operable refineries, yet the combined capacity was nearly identical at 17.6 million barrels per day. By 2014, only 140 refineries remained, but total capacity had actually risen to 18.02 million barrels per day. Fewer plants, bigger plants.

  The consolidation traced back to the 1980s, when a combination of economic and political factors brought new refinery construction to a virtual halt. More than half of the refineries that existed in 1981 have since closed, due to low utilization rates and industry mergers. No major new refinery was built from Marathon's Garyville, Louisiana facility in 1976 until the small Dakota Prairie Refinery in North Dakota began operation in 2014. The difficulty and cost of obtaining permits to build a modern refinery had become so significant that oil companies simply stopped trying.

  Environmental regulations also drove substantial investment in existing facilities. Refineries had to lower the sulfur content of diesel fuel and heating oil to comply with new standards, raise octane ratings, and meet air and water pollution requirements. In California's Contra Costa County and Solano County, refineries built in the early 20th century before the surrounding areas were densely populated now sit adjacent to urban communities in Richmond, Martinez, Pacheco, Concord, Pittsburg, Vallejo, and Benicia, occasionally requiring shelter-in-place orders for nearby residents when accidents occur.

• 7. Working Inside a Refinery

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  An explosion in a Chicago refinery killed 20 workers in 1890. Reports of health impacts from refinery work reach back that far, even before occupational injuries in the United States were routinely tracked. The hazards have not disappeared. Explosions were reported at refineries in Wisconsin and Germany in 2018.

  The interior of a refinery can reach noise levels in excess of 90 decibels. In the United States, 90 dB is the permissible exposure limit for an 8-hour workday, and any average above 85 dB over eight hours requires a formal hearing conservation program. Heat poses another threat: certain refining reactions require temperatures that can reach 1,600 degrees Fahrenheit. Chemical exposures run the full length of the process. Benzene, toluene, and xylene, collectively called BTX, are volatile organic compounds present throughout the refinery environment. Benzene alone has been linked to leukemia, and OSHA requires employers to conduct regular blood tests on exposed workers, including complete blood counts with cell differentials and peripheral blood smear reviews.

  A 2021 systematic review found that working in the petrochemical industry was associated with increased risk of certain cancers, including mesothelioma, though the same review found reduced risks for stomach and rectal cancers. Despite these risks, the regulatory picture tells a surprising story. A 2018 report by the US Bureau of Labor Statistics found that petroleum refinery workers had an occupational injury rate of 0.4 OSHA-recordable cases per 100 full-time workers. That compared to 3.1 cases across all industries, and 0.8 cases in oil and gas extraction specifically, suggesting that modern safety regulations have made the refinery floor significantly safer than the wider economy might suggest. California's CalOSHA adopted a policy in 2017 requiring refineries to perform a Hierarchy of Hazard Controls Analysis for each identified process safety hazard, building on the federal framework set by OSHA and NIOSH.

• 8. The World's Largest Refineries

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  For most of the 20th century, the Abadan Refinery in Iran held the title of the world's largest oil refinery. That position came to an end during the Iran-Iraq War, when the refinery suffered extensive damage. The Saudi Aramco refinery in Ras Tanura, Saudi Arabia was also at one point claimed as the world's largest.

  Since the 25th of December 2008, that distinction has belonged to the Jamnagar Refinery Complex in Gujarat, India, operated by Reliance Industries Limited. The complex consists of two refineries running side by side, with a combined production capacity of 1.24 million barrels per day. The corrosion problem at facilities like Jamnagar gives a sense of the scale of costs involved: as of 1996, corrosion-related direct costs in the US petroleum industry alone were estimated at 3.7 billion dollars. Carbon steel makes up more than 80 percent of refinery components because of its low cost and resistance to hydrocarbon corrosion at temperatures below 205 degrees Celsius, but more demanding environments require low alloy steels with chromium and molybdenum, or stainless steels, or in the most extreme cases, nickel, titanium, and copper alloys. Online corrosion monitoring technology has evolved to report corrosion rates up to twice per minute in real time, allowing engineers to treat corrosion as a process variable to be optimized rather than damage to be repaired after the fact.