Changes

==Origin of Coal==

==Origin of Coal==

[[File:Figure_1_sequence_coalification.JPG|200px|thumb|right|{{figure number1|}}Sequence Coalification. Adopted from Carlson<ref>Carlson, D., and C. Plummer, 2008, Physical geology: Earth revealed: New York, McGraw-Hill, 672 p.</ref>]]  

[[File:Figure_1_sequence_coalification.JPG|200px|thumb|right|{{figure number1|}}Sequence Coalification. Adopted from Carlson<ref name=Carlson>Carlson, D., and C. Plummer, 2008, Physical geology: Earth revealed: New York, McGraw-Hill, 672 p.</ref>]]  

Coal is a [[sedimentary]] rock with rich organic material that compacts in the coalification process. Coal is constructed in an environment with low oxygen content, such as swamps or bogs. Coal is easily known by its black color. Furthermore, if seen under a microscope it is apparent that it is the remains of  plants that are not fully decayed, such as leaves and roots.

Coal is a [[sedimentary]] rock with rich organic material that compacts in the coalification process. Coal is constructed in an environment with low oxygen content, such as swamps or bogs. Coal is easily known by its black color. Furthermore, if seen under a microscope it is apparent that it is the remains of  plants that are not fully decayed, such as leaves and roots.

Initially, coal forms when it accumulates plant remains with anoxic conditions, so plant cannot decay. Instead, the plants are attacked by bacteria that partly decomposes the organic material and liberates oxygen and hydrogen. When those elements come out, the percentage of carbon increases. Bacteria cannot fully decompose organic material because they are destroyed by acids liberated from plants<ref>Lutgens, F. K., E. J. Tarbuck, and D. G., 2012, Essentials of Geology: Upper Saddle River, New Jersey, Pearson Prentice Hall, 592 p.</ref>

Initially, coal forms when it accumulates plant remains with anoxic conditions, so plant cannot decay. Instead, the plants are attacked by bacteria that partly decomposes the organic material and liberates oxygen and hydrogen. When those elements come out, the percentage of carbon increases. Bacteria cannot fully decompose organic material because they are destroyed by acids liberated from plants.<ref>Lutgens, F. K., E. J. Tarbuck, and D. G., 2012, Essentials of Geology: Upper Saddle River, New Jersey, Pearson Prentice Hall, 592 p.</ref>

Plant remains acumulation built a peat which plant material easily known. Then peat slowly change to lignite (brown coal), which is early stage of coal formation. Because burial condition, it make pressure and temperature increase. This increases make chemical reaction, this reaction making coal losing water and gas and increasing carbon concentration. Lignite then become bituminus coal which have higher carbon concentration. If pressure and temperature increase coal bituminus become antracite, black coal with higest carbon concentration.  

Plant remains accumulates into a peat where plant material is easily known. Then peat slowly changes to lignite (brown coal), which is an early stage of coal formation. Because of the burial conditions, pressure and temperature increase. These increases make a chemical reaction where coal loses water and gas and increases carbon concentration. Lignite then becomes bituminus coal, which has higher carbon concentration. If pressure and temperature increase coal bituminus become antracite, black coal, with highest carbon concentration.  

Coal classified by degree of coalification (increasing organic carbon content) in terms coal rank (Table 1). Lignite and sub bituminus are low rank coal with low carbon content. Bituminus is midde rank and the higgest rank coal are known as antracite which has highest carbon concentration. <ref>Nichols, Gary. 2009. ''Sedimentology and Stratigraphy''. United Kingdom: A John Wiley & Son, Ltd</ref>

Coal classified by degree of coalification (increasing organic carbon content) in terms of coal rank ([[:File:Table 1 carbon and gas content in coal.JPG|Table 1]]). Lignite and sub-bituminus are low rank coal with low carbon content. Bituminus is middle rank and the highest rank coal are known as antracite which has the highest carbon concentration.<ref>Nichols, G., 2009, Sedimentology and stratigraphy: Hoboken, New Jersey, Wiley Blackwell, 432 p.</ref>

[[File:Table 1 carbon and gas content in coal.JPG|600px|thumbnail|center|Table 1 Carbon ang gas Content In Coal. Adapted from Carlson<ref>Carlson et al. 2008. ''Physical Geology: Earth Revealed''. New York: The McGraw-Hill Companies.</ref>]]

[[File:Table 1 carbon and gas content in coal.JPG|600px|thumbnail|center|{{table number|1|}}Carbon and gas content In coal. Adapted from Carlson<ref name=Carlson />]]

==Gas in CBM==

==Gas in CBM==