raffinerings

Raffinerings, or refining, is the industrial process of converting raw materials into more valuable, purer products by removing impurities and altering chemical or physical properties. It covers a range of sectors, including petroleum refining, metal refining, sugar refining, and chemical refining. Refining typically combines purification, conversion, and upgrading steps, often in integrated plants, synergistically employing heat, catalysts, solvents, and electrochemical methods.

Petroleum refining uses fractional distillation to separate crude oil into fractions; these may be treated to remove sulfur and other impurities; conversion units such as catalytic cracking, hydrocracking, and reforming create lighter fuels and feedstocks for petrochemicals. Products include gasoline, diesel, jet fuel, kerosene, heating oil, naphtha, and petrochemical feedstocks; blending and finishing yield specification fuels.

Metal refining involves processing ore concentrates to produce usable metals. Methods include smelting to extract base metals, and electrolytic or fire refining to achieve high purity. Examples include copper, nickel, and aluminum (often via the Hall–Héroult process); refining can also involve methods for precious metals, using electrochemical or chemical purification.

Sugar refining is the purification of raw sugar into white sugar. It typically involves affination or decolorization, clarification, filtration, crystallization, and centrifugation to remove impurities and molasses and to produce the desired crystallinity and quality.

Other refining activities include chemical refining of solvents and organic compounds, where purification and distillation, solvent extraction, and crystallization improve product quality. Raffinerings are energy-intensive and highly regulated, with ongoing advances in catalysts, process integration, and environmental controls to improve efficiency and reduce waste.