The procedure used to develop a coal char classification—Commission III Combustion Working Group of the International Committee for Coal and Organic Petrology

Lester, Edward; Alvarez, Diego; Borrego, Ángeles G.; Valentim, Bruno; Flores, Deolinda; Clift, D.A.; Rosenberg, Per; Kwiecińska, Barbara; Barranco, Richelieu; Petersen, Henrik I.; Mastalerz, María; Milenkova, K. S.; Panaitescu, C.; Marques, Marco Antonio; Thompson, A.; Watts, D. J.; Hanson, Simon; Predeanu, Georgeta; Misz, M.; Wu, Tao

doi:10.1016/j.coal.2009.10.015

Cited by 66 publications

(65 citation statements)

References 14 publications

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“…(++ big amount, + present, and − not found). Char forms using ICCP classification (Lester et al, 2010) The mineral compositions of the four samples of coal slurry were determined using X-ray diffraction and scanning electron microscopy. The mineral composition is dominated by quartz, pyrite and clay minerals, with slightly smaller amounts of barite and mica (Fig.…”

Section: Maceral-and Chemical Contents Of the Coal Slurriesmentioning

confidence: 99%

“…The ash samples were analyzed using the ICCP classification (Lester et al, 2010) in the reflected white light using a 200× oil objective.…”

Section: Tablementioning

confidence: 99%

“…Morphological studies of unburned particles of organic matter mainly focus on wall thickness, pore size and distribution and on particle diameter (Alvarez et al, 1997;Bailey et al, 1990;Cloke et al, 2003;Jones et al, 1985;Shibaoka, 1985;Taylor et al, 1998;Tsai and Scaroni, 1987). These morphological features have been used to create a classification of forms of unburnt organic matter (Lester et al, 2010;Misz, 2002;Tsai and Scaroni, 1987). Numerous publications provide valuable information on the formation and morphological characteristics of unburnt organic matter present in ashes from fluidized-bed boilers (e.g., Bowling and Waters, 1970;Sadhukhan et al, 2009;Valentim et al, 2006;Vleeskens et al, 1988).…”

Section: Introductionmentioning

confidence: 98%

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Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Jelonek

Mirkowski

2015

International Journal of Coal Geology

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Section: Maceral-and Chemical Contents Of the Coal Slurriesmentioning

confidence: 99%

“…The ash samples were analyzed using the ICCP classification (Lester et al, 2010) in the reflected white light using a 200× oil objective.…”

Section: Tablementioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Jelonek

Mirkowski

2015

International Journal of Coal Geology

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“…Petrographically, relics of the unburned organic matter are mainly present as char particles with different characteristics (morphotypes), including evidence of coking processes as well as features simply representing unburned coal (Lester et al, 2010;Hower, 2012;Hower and Mastalerz, 2001;Hower et al, 1995Hower et al, , 2005Suárez-Ruiz et al, 2015). Soot, i.e.…”

Section: Introductionmentioning

confidence: 96%

Vermicular kaolinite relics in fly ash derived from Bokaro and Jharia coals (Jharkhand, India)

Valentim

Flores

Guedes

et al. 2016

International Journal of Coal Geology

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“…The coals undergo complex physical and chemical transformations, giving off volatiles and producing solid residues (char). The resulting char (termed coal fly ash by Grasby et al, 2011) is highly variable depending on the organic constituents of the precursor coal (Bailey et al, 1990;Yu et al, 2007;Lester et al, 2010), and the morphology of the char ranges from solid to vesicular. Vesicular chars, in particular in late Permian sediments from Lake Buchanan in Arctic Canada, have been interpreted as definitive evidence of coal combustion.…”

Section: Introductionmentioning

confidence: 99%

Latest Permian chars may derive from wildfires, not coal combustion

Hudspith

Rimmer

Belcher

2014

Geology

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7The Permian-Triassic extinction event was the largest biocrisis of the Phanerozoic. One 8 of the principle triggers for the 'big dying' is thought to be greenhouse warming resulting from 9 the release of CH 4 from basalt-coal interaction during the extensive Siberian Trap eruptions. 10Observations of organic matter interpreted to be coal combustion products (fly ash) in latest 11Permian marine sediments have been used to support this hypothesis. However, this 12 interpretation is dependent upon vesicular chars being fly ash (coal combustion-derived) and not 13 formed by alternative mechanisms. Here we present reflectance microscopy images of vesicular 14 chars from Russian Permian coals, as well as chars from modern tundra, peatland and boreal 15forest fires, to demonstrate that despite a difference in precursor fuels, wildfires are capable of 16 generating vesicular chars that are morphologically comparable to end Permian 'fly ash'. These 17 observations, coupled with extensive global evidence of wildfires during this time interval calls 18 into question the contribution of coal combustion to the end Permian extinction event. 19 INTRODUCTION 20The Permian-Triassic boundary event decimated 80-96% of marine and 70% of terrestrial 21 life and is marked in the geological record by a significant 2-8‰ negative organic and carbonate 22Publisher: GSA Journal: GEOL: Geology Article ID: G35920Page 2 of 15 δ 13 C excursion (Chen and Benton, 2012). One suggestion is that massive greenhouse warming 23 (Erwin, 1994) led to the most significant mass extinction event ever to occur on our planet. One 24 of the greenhouse contributors is thought to have been extensive CH 4 release from the 25 combustion of coals and organic-rich shales, during the emplacement of shallow intrusions, as 26 part of the Siberian Trap eruptions (Retallack and Jahren, 2008; Grasby et al., 2011; Ogden and 27 Sleep, 2012). 28In modern coal-fired power stations char is produced during high temperature 29 combustion of pulverized coal. The coals undergo complex physical and chemical 30 transformations, giving off volatiles and producing solid residues (char). The resulting char 31 (termed 'coal fly ash' in Grasby et al. (2011)) is highly variable depending on the organic 32 constituents of the precursor coal (Bailey et al., 1990; Yu et al., 2007; Lester et al., 2010), and 33 the morphology of the char ranges from solid to vesicular. Vesicular chars in particular, in Late 34Permian sediments from Lake Buchanan in Arctic Canada have been interpreted as definitive 35 evidence of coal combustion. These chars represent the only physical indicator of coal 36 combustion outside of Siberia and have been used extensively as evidence for global dispersal of 37 coal fly ash at the end Permian extinction event (Grasby et al., 2011; Ogden and Sleep, 2012; 38 Sanei et al., 2012; Knies et al., 2013; Kerr, 2013). In order to transport these coal combustion 39 chars 20,000 km from the Siberian Trap source, models imply that explosive interactions of coal ...

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The procedure used to develop a coal char classification—Commission III Combustion Working Group of the International Committee for Coal and Organic Petrology

Cited by 66 publications

References 14 publications

Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Petrographic and geochemical investigation of coal slurries and of the products resulting from their combustion

Vermicular kaolinite relics in fly ash derived from Bokaro and Jharia coals (Jharkhand, India)

Latest Permian chars may derive from wildfires, not coal combustion

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