Coal

Today, I want to present a different article. about a very familiar resource💁‍♀️

Sukandarrumidi 1995 said that coal is a solid hydrocarbon fuel that is formed from the peat and coal processes inside a basin (swamp area) over a period of time geological which includes bio-geochemical activity on accumulation of flora in nature that contains cellulose and lignin. The coalification process is also assisted by factors pressure (related to depth), and temperature (associated with a reduction in internal water content coal). Coal can be defined as rock sediment formed from the decomposition of piles plants for approximately 300 million years. Decomposition This plant occurs due to biological processes with microbes where much of the oxygen in cellulose is converted into carbon dioxide (CO2) and water (H2O). The changes occurs in the content of these materials due to pressure, heating which then forms thick layer as a result of the influence of deep geothermal heat a period of millions of years, so that layer finally solidifies and hardens (Mutasim, 2010).


According to Irwandy 2014, coal is also known as black “gold”. People know him as black stone that can burn. It's not wrong because the field view shows the contrast difference between coal and surrounding rocks (Figure 1.2). Coal is defined by several experts and has There are many definitions in various books or references. In industrial community, this definition is even more specific, namely rocks that at a certain level of quality have value economy. Elliot (1981) which is coal geochemistry, argue that coal is a sedimentary rock which is chemically and physically heterogeneous 7 contains the elements carbon, hydrogen and oxygen as the main elemental components and sulfur and nitrogen as an additional element. Other substances, namely inorganic compounds forming ash (dust), dispersed as particles of mineral substances which are separated throughout the coal compound. Succinctly, Coal can be defined as carbonate rock dense, brittle, dark brown to black, flammable, resulting from changes plants chemically and physically. According to Miller 2005, coal is found in deposits called layers that originate from accumulation vegetation that has undergone physical and chemical changes. These changes include the decay of vegetation, deposition and burial by sedimentation, compaction, and transformation of plant remains into organic rocks found today. Coal has characteristics that vary throughout the world in type of plant material stored (coal type), in degree of metamorphism or coal (coal rank), and within the range of impurities included (stone content coals)

Based on its quality, coal has classes (grade) which are generally classified into four primary class according to ASTM standards (Kirk-Othmer, 1979) or five classes if peat is included as 13 the youngest type of coal (Larsen, 1978). In terms of These coal classes are accompanied by criteria based on proximate analysis and heating value, also criteria based on ultimate analysis and total sulfur content as well as its density. Each type of coal respectively have the ratios C : O and C : H higher. Anthracite is a coal the most valuable, and lignite, the most valuable low.

1. Peat, this group actually includes a type of coal, however is fuel. This is caused by is still an early phase of the formation process coal. This precipitate still shows properties starting from the basic ingredients (plants).
2. Lignit, is often called brown-coal, this group has shown the next process in the form of stumpy structure and layering symptoms. If dried, then the gas and water will come out. This deposit can be used on a limited basis for simple interests, because it is hot issued is very low so often used as fuel for power plants electricity. This group actually includes a type of coal, however is fuel. This is caused by is still an early phase of the formation process coal. This precipitate still shows properties starting from the basic ingredients (plants).
3. Subbituminous, this group shows certain characteristics, namely blackish color and already pregnant candle. This sediment can be used for utilization sufficient combustion at the right temperature not too high. Subbituminous is commonly used as a steam power plant. Subbituminous is also a source of raw materials which is important in the manufacture of aromatic hydrocarbons in the synthetic chemical industry.
4. Bituminous, is a solid, colored mineral black and sometimes dark brown, brittle with forming layered prismatic blocks and does not emit gas and water when dried often used for transportation purposes and industry as well as for steam power plants.
5. Antrasit, this group is black, hard, high gloss, and the fragments show chocoidal fragments. During the combustion process it shows a blue color with a high degree of heating. Used for various large industries requires high temperatures.

source :
https://id.wikipedia.org/wiki/
http://eprints.upnyk.ac.id/