In the decade after World War II, developed countries basically accomplished the historic change of what replaced coal as the primary energy source.

During the decade after World War II developed countries basically accomplished the historic change of what replaced coal as the primary source of energy

(1) Coal and Oil Era. Before the 1820s it was called the "Coal and Oil Era ". At that time, people only refined kerosene from petroleum and used it for lighting. Kerosene became the most fashionable and brightest oil for lamps in the world. The gasoline component of petroleum, which is lighter than kerosene, and the other components, which are heavier than kerosene, were discarded as flammable and explosive hazards or dirty and smelly waste products.

(2) The gasoline era: The internal combustion engine was invented in 1878; the automobile was introduced in 1885. Cars were originally called "autos" because their engines burned gasoline, so they were simply called automobiles. As a large number of cars need gasoline, and the gasoline component contained in the oil is limited, so the other components of the heating and cracking into gasoline component of the cracking industry came into being, thus promoting the development of the petroleum industry. 1911 gasoline sales for the first time more than kerosene, to the 20th century after the 1920s, oil is mainly used to refine gasoline, and is therefore referred to as the "Gasoline Era ".

(3) the era of fuel and chemical raw materials. after 1940, the development of the chemical industry needs to use petroleum products as its high-quality raw materials, and gradually formed the emerging petroleum and natural gas as raw materials for the petrochemical industry. 1951-1967, the developed countries basically completed the oil instead of coal to become the primary energy source of the historic change. In addition to modern jet airplanes and the development of aviation, the requirement of high-quality petroleum products as fuel. In this way, the petroleum industry has developed to the age of fuel and chemical raw materials.