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How do petroleum refinery conversion processes increase the yield of transportation fuels?
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petroleum refining
Aerial view of an oil refinery near New Orleans.
Petroleum refineries use conversion processes to chemically alter the molecular structure of crude oil components, transforming heavy, low-value fractions into lighter, high-value transportation fuels like gasoline and jet fuel. While simple distillation separates crude oil based on physical properties, it cannot meet modern demand for light products; conversion is essential to increase these yields.123
Key conversion methods include:
- Thermal Cracking: Uses high heat to split large, heavy molecules into smaller, lighter ones. Variations include visbreaking, which reduces the viscosity of residual fuels, and coking, a severe form of thermal cracking that converts heavy residues into lighter oils and solid coke.23
- Catalytic Cracking: Employs catalysts (such as zeolites) to crack heavy gas oils into high-octane naphtha under less severe conditions than thermal methods. This process is a foundation of modern refining.4
- Hydrocracking: A versatile catalytic process performed in the presence of hydrogen. It allows for the flexible production of high-quality gasoline, jet fuel, or lubricating oils from heavy feedstocks.52
These processes collectively enable refineries to maximize the output of fuels required for modern transportation.2