Jet fuel, also known as Aviation Turbine Fuel (ATF), is a specialized type of fuel crafted for gas-turbine engine-powered aircraft. Its variations in grades and specifications cater to diverse regions and intended applications. In civil aviation, Jet A-1 and Jet A are primary, while Jet B finds limited use, notably in frigid climates. Military jet fuels like JP-4, JP-5, and JP-8 feature distinct additives and specifications tailored to military aircraft requirements. Each grade adheres to stringent standards ensuring safety and performance. The diversity in jet fuel types reflects the nuanced demands of aviation across different environments and operational needs. With global air travel reliant on these fuels, their quality, compatibility, and reliability remain paramount for the aviation industry's safe and efficient functioning.

EN 590 is a crucial standard for diesel fuel in Europe and other countries. It's been pivotal in reducing sulfur content, leading to the production of ultra-low-sulfur diesel (ULSD). This shift has been essential for mitigating emissions from diesel engines, particularly in densely populated urban areas. The transition to ULSD has been accompanied by the implementation of stricter emissions standards, such as Euro IV and Euro V, which have progressively lowered the permissible sulfur content in diesel fuel. The various measures taken by different countries within the European Union to accelerate the adoption of cleaner diesel fuels, including tax incentives and earlier implementation of stricter standards. These initiatives reflect a broader commitment to environmental sustainability and public health.

Crude oil, often referred to as "black gold," is a vital natural resource formed from ancient organic materials. Through a process of geological pressure and heat over millions of years, these materials have transformed into hydrocarbon deposits. When extracted via drilling, it is usually accompanied by other substances like natural gas and saline water. It serves as the primary feedstock for the production of various fuels and petrochemicals upon refinement. Crude oil reserves are exhaustible. The refining process begins with distillation, where it is heated and separated into its constituent components based on their boiling points. This process is essential for producing a wide array of products, including gasoline, diesel, kerosene, and asphalt, which are integral to modern economies and industries.

Petroleum coke, or Petcoke, is a carbon-rich solid derived from oil refining processes like coking. It can also stem from bitumen extracted from oil sands. With various forms like needle, honeycomb, sponge, and shot coke, petcoke's properties differ based on microstructure. Through high-temperature and high-pressure treatments, residual oils undergo coking, shedding gases and volatiles to yield petcoke. Further refinement via calcination produces calcined petroleum coke, vital in crafting anodes for aluminum and steel manufacturing. Petcoke's CO2 emissions surpass those of coal per energy unit, raising environmental concerns. Its categorization as fuel grade or anode grade hinges on sulfur and metal concentrations. Despite environmental debates, Petcoke remains pivotal in industries.

Bitumen, also known as asphalt, is a dense, sticky substance derived from petroleum. Predominantly utilized (70%) in road construction, it serves as the binding agent when mixed with aggregate to form asphalt concrete. Additionally, it finds application in bituminous waterproofing products like roofing felt and flat roof sealants. Historically, "asphaltum" was a term used interchangeably with "bitumen" before the 20th century. In American English, "asphalt" or "asphalt cement" denotes the refined residue from specific crude oil distillation processes, while internationally, it's often referred to as "bitumen." Geologists globally prefer "bitumen" for the naturally occurring variety. Informally, various asphalt forms are colloquially termed "tar," as seen in the La Brea Tar Pits.

Recycled oils, often referred to as used oils, are those that have fulfilled their initial purpose in machinery, vehicles, or industrial equipment and have subsequently been drained or removed. These oils can be contaminated with impurities, such as dirt, metals, or chemicals, from their previous use. Despite this, they still possess valuable lubricating properties that can be reclaimed through recycling processes. Through refining and treatment methods, these used oils are purified to remove contaminants and restore their lubricating properties. The resulting recycled oils are used as base oils for manufacturing new lubricants or as additives in various industrial applications. This recycling process extends the lifespan of the oil and also reduces the need for virgin oil production.