Fossil fuels

fossil fuels are also called fossil fuels. Until now, almost all the fuels used in the world have been fossil fuels, namely oil, gas and coal. Natural fossil fuels, which have evolved over millions of years, could be depleted by humans within a few hundred years. Observations and studies have shown that there is no coal or oil forming in the ground today. Oil, also known as crude oil, is a yellow-to-black flammable viscous liquid that often coexists with natural gas and is a complex mixture. The properties of oil vary widely depending on the origin, and the density, viscosity and solidification points vary widely, for example, the solidification points are as high as 30 degrees C and some are as low as -66 degrees C. Heat values range from 43.7 to 46.2MJ/kg. The boiling point of each group in petroleum is also very different, from 25 degrees C to 500 degrees C or more. The main elements in oil are carbon and hydrogen, accounting for 83 to 87% and 11 to 14%, respectively. It also contains small amounts of sulfur (0.06 to 8%), nitrogen (0.02 to 1.7%), oxygen (0.08 to 1.8%) and trace metal elements (nickel, vanadium, iron, copper) and so on.
natural gas is broadly referred to as naturally formed gas buried in the formation. But natural gas is usually referred to only as flammable gases (gaseous fossil fuels) stored deeper in the formation and gases that coexist with oil (often referred to as oil fields). The main component of natural gas is methane. In addition, depending on geological conditions, it contains different quantities of low-carbon alkanes such as ethane, propane, butane, propane and hexane, as well as non-hydrocarbon substances such as carbon dioxide, nitrogen, hydrogen and sulphides. Some gas fields also contain helium. Natural gas with high methane content is called dry gas, and natural gas with two or more carbon atoms and alkanes is called moisture. China's Sichuan Zigong is rich in natural gas.
, also known as coal, is a solid flammable mineral buried underground. Coal is a mixture, there is no single molecular structure, after long-term research by scientists, there has been a general type of coal structure introduction. The structure of coal contains a large number of carbon atomic rings, some of which thicken with each other and others bond to the growth chain. More common is W. H. Huai Ze's soot structure model, but has not yet been able to reveal the real structure of coal. The most
organic
coal is mainly carbon, followed by hydrogen, as well as oxygen, nitrogen and sulfur.