Published October 2016
The primary uses for naphtha and gas oil are the production of fuels, gasoline for naphtha, and diesel for gas oil. A secondary use for naphtha is as a feedstock for steam cracking to produce petrochemicals (ethylene, propylene) and the production of aromatic petrochemical products (benzene, toluene, and xylenes). Gas oil is used as a chemical feedstock for steam cracking, although generally less preferred than naphtha and natural gas liquids (NGLs, including liquefied petroleum gases).
Naphtha and gas oil refinery outputs depend on the composition of feed crude petroleum utilized and in turn the crude oil regional source. Crude oil extracted from Middle Eastern fields has different properties from that extracted in Alaska. Crude oils with an API gravity of 30° or more produce larger amounts of products such as naphtha, kerosene, and light gas oils than those with an API gravity of less than 30°. In addition, naphthenic crude oils tend to produce relatively greater quantities of naphtha than the paraffinic crudes of the same specific gravity, which produce higher relative amounts of gas oils.
The following pie charts show world consumption of naphtha and gas oil in 2016.
Light naphtha consumption will increase rapidly worldwide, except in North America, driven primarily by steam cracker feedstock demand. Most of the demand growth will be in Southeast Asia, India, and the Middle East. Consumption of light naphtha is also increasing in North America, in particular Canada, as a diluent for heavy crude blending, and somewhat for direct blending into gasoline and isomerization for octane enhancement. In 2016, steam cracking accounted for most of the world consumption, followed by direct blending into motor gasoline and isomerization.
Heavy naphtha consumption is forecast to increase at 1.6% annually during 2016–21. Aromatics and gasoline production are the leading drivers for growth. As more heavy naphtha becomes available from refineries, the exports growth rate will decline. In 2016, the majority of heavy naphtha is used as reformer feed for production of aromatics and high-octane gasoline. Combined with direct blending into motor gasoline, the percentage increases even more.
Most heavy naphtha is used as reformer fuel, split between reforming for gasoline and reforming for aromatics. If one also considers direct blending of motor gasoline, the ratio is skewed even more toward for gasoline production. Toluene, xylenes, and heavy aromatics that are produced in chemical reformers in excess of what is needed to meet downstream chemical and solvent demand is blended into the gasoline pool as high-octane fuel components.
The transportation sector accounted for almost 70% of gas oil consumption, accounted for primarily by domestic transportation (motor vehicle consumption of diesel) and international bunkers (primarily marine fuel). Industrial (and commercial) usage is the second-largest application for gas oil, with growth forecast at 1.2% annually during 2016–21. Industrial is typically light heating oil for industrial and commercial uses. Transformation is the third-largest application, with consumption forecast to decline at 1.0% annually during 2016–21. Transformation processes include conversion of primary forms of energy to secondary and further transformation to produce electricity or heat. Energy accounted for 1.5% of gas oil consumption, and is forecast to grow at 0.5% annually during 2016–21. Energy includes use and losses by the energy industry itself during the refinery process. Overall gas oil consumption is forecast to increase at 1.4% per year during 2016–21.