The basic purpose of a refinery is to separate and transform these various hydrocarbon groups so that they may be used, combined or further treated to create the thousands of products made from petroleum. Because hydrocarbons vaporize at different temperatures, the crude oil is heated and the mixture of hot vapors and liquid goes into the tower. The liquid or residual oil is drawn off at the bottom to be used as asphalt or heavy fuel. The Petroleum Industry Today Oil and natural gas supply 65 percent of the energy used in the United States today. Oil products fuel planes, trains, cars, trucks, buses and motorcycles.
Oil also is used to heat homes.
Chemicals made from oil are used to make products ranging from makeup, toys, fabrics, sneakers and football helmets to aspirin, toothpaste, deodorant, clothes, hair dryers and lipstick. Plastics made from oil are widely used in everything from compact discs and videocassette recorders to computers, TVs and telephones. Oil industry investment in the United States totals half a trillion dollars in wells, refineries and distribution systems. This is five times the size of the U.S. automobile industry. The industry employs 1.5 million people directly and 6 million people indirectly.