Where does the energy of coal, oil and natural gas finally come from?

Coal energy ultimately comes from plants, and petroleum energy ultimately comes from marine life. The energy of natural gas ultimately comes from biogas.

Formation of coal: the accumulation layer of ancient plant remains of coal was formed after long-term geological action after being buried underground.

The formation of oil: oil comes from ancient organic matter. In the long geological era, a large number of marine life has been bred in the ocean. Their bodies sank to the bottom of the sea with the sediment, piled up layer by layer for many years, isolated from the outside air. After the decomposition of bacteria and the high temperature and high pressure in the formation, the biological remains are gradually decomposed into oil and natural gas.

Natural gas is contained in underground porous rocks, including oil and gas, gas field gas, coalbed methane, mud volcanic gas and biogas, and a small amount comes from coal seams. It is a high-quality fuel and chemical raw material.

Natural gas is mainly used as fuel to produce carbon black, chemicals and liquefied petroleum gas. Propane and butane produced from natural gas are important raw materials for modern industry. Natural gas is mainly composed of gaseous low molecular hydrocarbons and non-hydrocarbon gases.

Extended data:

Under the normal temperature and pressure of the surface, the plant residues accumulated in stagnant water are transformed from peat or sapropelic mud into peat or sapropelic mud; After peat or sapropelic mud is buried, it sinks into the deep underground due to the decline of basin basement and is transformed into lignite by diagenesis. When the temperature and pressure gradually increase, it is transformed into bituminous coal to anthracite by metamorphism. Peatization refers to the process that the remains of higher plants accumulate in swamps and are transformed into peat through biochemical changes.

Due to the continuous accumulation and thickening of sediments, the temperature and pressure of oil rise. With the continuous advancement of this process, sediments become sedimentary rocks and then form sedimentary basins, providing a basic geological environment for the generation of oil. Most geologists believe that oil, like coal and natural gas, is gradually formed by long-term compression and heating of ancient organic matter.

According to this theory, oil is formed by the changes of prehistoric marine animals and algae corpses. After a long geological period, these organic substances are mixed with silt and buried under thick sedimentary rocks. Under the high temperature and pressure in the underground, they gradually transform, first forming waxy oil shale, and then degenerating into liquid and gaseous hydrocarbons.

Because these hydrocarbons are lighter than the nearby rocks, they penetrate upward into the nearby rocks until they penetrate into the tightly impermeable rocks above, and the rocks themselves are empty. The oil accumulated in this way forms an oil field.

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