![]() The grade of coal produced depended on the maximum pressure and temperature reached, with lignite (also called "brown coal") produced under relatively mild conditions, and sub-bituminous coal, bituminous coal, or anthracite coal (also called "hard coal" or "black coal") produced in turn with increasing temperature and pressure. Then, over millions of years, the heat and pressure of deep burial caused the loss of water, methane and carbon dioxide and increased the proportion of carbon. This trapped the carbon in immense peat bogs that were eventually deeply buried by sediments. In these wetlands, the process of coalification began when dead plant matter was protected from biodegradation and oxidation, usually by mud or acidic water, and was converted into peat. At various times in the geologic past, the Earth had dense forests in low-lying wetland areas. The conversion of dead vegetation into coal is called coalification. Fossils and amber may be found in coal.įormation Example chemical structure of coal GeologyĬoal is composed of macerals, minerals and water. Germanic cognates include the Old Frisian kole, Middle Dutch cole, Dutch kool, Old High German chol, German Kohle and Old Norse kol, and the Irish word gual is also a cognate via the Indo-European root. The word originally took the form col in Old English, from Proto-Germanic * kula( n), which in turn is hypothesized to come from the Proto-Indo-European root * g( e) u-lo- "live coal". Indonesia and Australia export the most, followed by Russia. The largest consumer and importer of coal in 2020 was China, which accounts for almost half the world's annual coal production, followed by India with about a tenth. To meet the Paris Agreement target of keeping global warming below 2 ☌ (3.6 ☏) coal use needs to halve from 2020 to 2030, and "phasing down" coal was agreed upon in the Glasgow Climate Pact. Global coal demand is set to remain at record levels in 2023. Global coal use was 8.3 billion tonnes in 2022. The United Nations Secretary General asked governments to stop building new coal plants by 2020. As part of worldwide energy transition, many countries have reduced or eliminated their use of coal power. Fourteen billion tonnes of carbon dioxide were emitted by burning coal in 2020, which is 40% of the total fossil fuel emissions and over 25% of total global greenhouse gas emissions. The use of coal damages the environment, and it is the largest anthropogenic source of carbon dioxide contributing to climate change. The extraction and use of coal causes premature death and illness. Some iron and steel-making and other industrial processes burn coal. In 2020, coal supplied about a quarter of the world's primary energy and over a third of its electricity. With the invention of the steam engine, coal consumption increased. ![]() While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous ( Pennsylvanian) and Permian times. Ĭoal is a type of fossil fuel, formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |