Scientists from the United States have discovered microbes involved in the formation of coal which emit methane. The article devoted to the mechanism of coal formation was published in the journal Science.
Coal is formed when plant matter in swampy forests falls into water and is quickly buried. Organic matter becomes peat, then lignite, then brown coal, then bituminous coal, and finally anthracite, the richest in carbon. Carbonization converts methoxyl groups (made up of carbon, oxygen, and three hydrogen atoms) to methane, but how this happens has remained undisclosed.
In order to better understand this process, researchers from State University The Pennsylvania California Institute of Technology analyzed stable carbon isotopes in methoxyl groups from coal samples collected around the world. It was found that the isotope profile does not correspond to the mechanism of formation of methane from coal under the influence of heat, increased acidity or catalytic reactions. Instead, it corresponded to the formation process under the influence of microorganisms.
“It turned out that aerobic microbes are good at decomposing carbon cycles – which anaerobic ones cannot. One of the few things they can do is cut off the methoxyl sites, ”explains one of the researchers, associate professor at Penn State University Max Lloyd. The released groups are gradually converted to methane. After the separation of all methoxyl radicals, the reaction stops.