After the discovery of crude oil in 1287 SH (1909 AD) in the Masjed Soleiman region of Abadan Island due to its proximity to oil-rich areas, its location between the rivers of Arvand and Bahmanshir, its 71-kilometer distance from the Persian Gulf, and its accessibility to international waters, Abadan was chosen as the site for the first refinery. Therefore, the foundation stone of the refinery was laid in 1287 SH (1910 AD), and Abadan Refinery began operating in 1291 (1912 AD) with a capacity of 2,500 barrels per day as the country's first oil refinery. During the years of World War I, Abadan Refinery underwent further expansion to meet the increased demand for fuel for warships. The development of Abadan Refinery gained momentum in 1312 SH (1932 AD) with the cancellation of the existing ANGELO IRANIAN contract and the signing of a new oil agreement. The turning point in the new agreement was to make the necessary provisions for the training and preparation of Iranians to replace foreigners, and for this purpose, the foundations of the Abadan Oil College were laid. This college was established in 1318 SH and inaugurated in 1319 SH. During World War II, after the Allies lost the oil and refinery in Bremen, more attention was focused on the expansion of Abadan Refinery. Abadan became the largest refinery in the world, gaining international fame for supplying and delivering aviation gasoline at a rate of 25,000 barrels per day during the war. The production of aviation gasoline from Abadan Refinery played a significant role in the Allies' victory. With the nationalization of the oil industry in 1329 SH (1950 AD) and the departure of foreigners in 1330 SH (1951 AD), the responsibility for supplying petroleum products for domestic use, maintenance, and industrial protection of this immense refinery was entrusted to the employees working at that time. In 1333 SH (1954 AD), a contract was signed with an international consortium. According to this contract, once again, the products of Abadan Refinery were exported to international markets at a rate of up to 300,000 barrels per day. During this period, small and outdated equipment was replaced with larger and modernized machinery, increasing their capacity. During the period of the famous "Cham" project, which resulted in the centralization of crude oil exports in Khark Island, the delivery of crude oil from the Mahshahr port, which was the crude oil export port, was redirected to Abadan Refinery. After renovation, it was transformed into an export port for petroleum products from Abadan Refinery. The above project was inaugurated in 1346 SH (1967 AD) and immediately put into operation. In the Iranian calendar month of Mordad 1352 (July 31, 1973), with the enactment of the Law on Iran's Sovereignty over Oil Resources, the administration and control of Abadan Refinery directly came under the supervision of the National Iranian Oil Company. After the administration and control of the refinery by the National Iranian Oil Company, the Abadan Refinery development plan was presented, immediately approved, and the design and construction work for this project were completed in Khordad 1356 (May 1977), increasing the daily capacity from 460,000 barrels to 600,000 barrels. From Shahrivar 1356 (August 1977), the refinery went into operation, reclaiming its global status and becoming the largest refinery in the world. On the morning of the 31st of Shahrivar 1359 (September 22, 1980), when the employees were heading to the refinery for their daily activities, the terrifying sound of artillery shells and tank gunfire echoed, and the Abadan Refinery fell victim to the dark arrows of mercenary agents, marking a new chapter of the efforts and sacrifices of the employees during the years of the Sacred Defense. With the establishment of emergency headquarters and their round-the-clock efforts, the employees of Abadan Refinery managed to evacuate numerous refinery units of petroleum products and safeguard many units and equipment, despite new damages to the facilities. With incredible courage and dedication, and in honor of 244 martyrs, they succeeded in transferring several billion dollars' worth of exclusive equipment and components from the refinery to secure locations. Before the imposed war, Abadan Refinery had four distillation units, each with an approximate capacity of 100,000 barrels per day, one distillation unit with a capacity of 130,000 barrels per day, numerous production and refining units for various products, and 850 storage tanks for petroleum materials. During the war, many of these units were destroyed, and after the acceptance of a resolution, the Phase 1 of the refinery with a capacity of 130,000 barrels per day was reconstructed and inaugurated on April 1, 1989, under the auspices of the esteemed Supreme Leader during his presidency. Following the launch of Phase 1, other refinery units, including distillation units 70, 80, 75, vacuum distillation units 60 and 55, catalytic conversion, gas separation, catalytic cracking, solvent production, and oil refinery, were put into production without the need for foreign personnel, thanks to the round-the-clock efforts of the refinery's employees and the participation of employees from other refineries. Currently, it has a capacity of producing the following products at 400,000 barrels per day: 1) liquefied gas, 2) motor gasoline, 3) white oil, 4) gas oil, 5) jet fuel, 6) furnace oil, 7) various base motor oils, 8) various bitumens, 9) various petroleum solvents, 10) sulfur, 11) naphtha (feedstock for petrochemical plants in Bandar Imam), and 12) gas (feedstock for petrochemical plants in Abadan). The development plan for Abadan Refinery consists of three phases: In the first phase of the development plan, the capacity of the distillation unit increased from 130,000 to 180,000 barrels per day. The vacuum distillation unit with a capacity of 200,000 barrels per day and the hydrotreating unit with a capacity of 25,000 barrels per day for reducing furnace oil and supplying feedstock to the catalytic cracking unit became operational in 2005. In the second phase, the plan focuses on stabilizing the current capacity and improving the quality of the refinery's products. This project includes atmospheric and vacuum distillation units, gasoline treatment units, white oil units, gas oil units, sulfur production units, the construction of the second catalytic cracking complex, an increase in gasoline production, and other auxiliary units. This project is currently being pursued by the National Iranian Engineering Company for Refinery and Distribution. The third phase includes the construction of the catalytic cracking and alkylation complex, butane isomerization, and the revamp of the acid unit. The aim of this project is to increase gasoline production and reduce furnace oil. After the implementation of this project, gasoline production will increase by 6 million liters per day. In future development plans, special attention will be given to environmental issues. Various types of filters and scrubbers will be used to prevent air pollution, industrial wastewater treatment, and closed-loop cooling water systems. These units are equipped with advanced technology to minimize energy waste. The establishment and operation of an industrial wastewater treatment unit will completely solve the problem of Arvandroud River pollution.