petroleum refining

Petroleum is refined to produce gasoline and other petroleum products from crude oil. The refining process begins with the fractional distillation of heated crude oil. The crude-oil components (gas, gasoline, naphtha, kerosene, light and heavy gas oils, and residuum) are separated into lighter and heavier hydrocarbons. Light hydrocarbons are drawn off the distilling column at lower temperatures than are heavy hydrocarbons. The components are then treated in many different ways, depending on the desired final products (shown at the bottom). The conversion processes (shown as blue boxes) are discussed in the article. For simplification, not all of the products of the conversion processes are shown in the diagram.Encyclopædia Britannica, Inc.
Related Articles:petroleum : REFINING PETROLEUM (Britannica Student Encyclopedia)
In a refinery, crude oil is separated into useful products such as gasoline, kerosene, diesel fuel, home heating fuel, lubricating oils, and asphalt. Because refineries use water for cooling, they are built along water sources, such as rivers.