User:Milton Beychok/Sandbox: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Milton Beychok
No edit summary
imported>Milton Beychok
No edit summary
Line 1: Line 1:
==Coal analysis==


The composition of a coal is usually reported in terms of its '''proximate''' analysis and its '''ultimate analysis''':
*The proximate analysis consists of four items: fixed carbon, volatile matter, moisture and ash, all on a weight percent basis.
*The ultimate analysis provides an element-by-element composition of the coal's organic fraction, namely:  carbon, hydrogen, oxygen and sulfur, all on a weight percent basis.
Both the proximate and the ultimate analysis may be reported on an ''as received'' (ar) basis, a ''dry'' (d) or ''moist'' basis, an ''ash-free'' (af) basis, a ''mineral matter-free'' (mmf) basis and various combinations of those bases. For example, an analysis may report the basis to be: as received (ar), dry and ash-free (daf), moist and ash-free (maf), dry and mineral matter-free (dmmf) or moist mineral-matter free (moist mmf).
Ash and mineral matter are two distinctly different entities. Mineral matter consists of the various minerals contained in the coal. Ash is the inorganic solids remaining after the coal is completely combusted. The ash is usually less than the mineral matter because of the weight changes that take place during coal combustion such as the loss of gaseous CO<sub>2</sub> from mineral carbonates, loss of water from silica minerals and loss of sulfur (as gaseous SO<sub>2)</sub>) from iron pyrites.
Some examples of proximate and ultimate analyses are given in the table below:
{| class = "wikitable" align="center"
|+ Examples of Proximate and Ultimate Analyses <ref>{{cite book|author=Chris Higman and Maarten van der Burgt|title=Coal Gasification|edition=2nd Edition|publisher=Gulf Professional Publishers|year=2008|id=ISBN 0-7506-8528-X}}</ref>
!rowspan="2"|<br><br><br><br>Coal Rank||colspan="4"|Proximate Analysis<br>(wt % ar) ||colspan="5"|Ultimate Analysis<br>(wt % maf)||rowspan=2|Net<br>Heating<br>Value<br>(maf)<br>(MJ/kg)
|- align="center"
!Fixed<br>carbon||Volatile<br>matter||<br>Moisture ||<br>Ash ||<br>C||<br>H||<br>O||<br>N||<br>S
|-
|Anthracite||align="center"|81.8||align="center"|7.7||align="center"|4.5||align="center"|6.0||align="center"|91.8||align="center"|3.6||align="center"|2.5||align="center"|1.4||align="center"|0.7||align="center"|36.2
|-
|Bituminous||align="center"|54.9||align="center"|35.6||align="center"|5.3||align="center"|4.2||align="center"|82.8||align="center"|5.1||align="center"|10.1||align="center"|1.4||align="center"|0.6||align="center"|36.1
|-
|Subbituminous||align="center"|43.6||align="center"|34.7||align="center"|110.5||align="center"|11.2||align="center"|76.4||align="center"|5.6||align="center"|14.9||align="center"|1.7||align="center"|1.4||align="center"|31.8
|-
||Lignite||align="center"|27.8||align="center"|24.9||align="center"|36.9||align="center"|10.4||align="center"|71.0||align="center"|4.3||align="center"|23.2||align="center"|1.1||align="center"|0.4||align="center"|26.7
|-
|colspan="12"|'''Notes''':<br>
• wt % = percent by weight &nbsp; &nbsp; ar = as received &nbsp; &nbsp; maf = moisture and ash free<br>
• C = Carbon &nbsp; &nbsp; H = Hydrogen &nbsp; &nbsp; O = Oxygen &nbsp; &nbsp; N = Nitrogen &nbsp; &nbsp; S = Sulfur <br>
• Multiply [[Net Heating Value]]s in M[[Joule|J]]/[[Kilogram|kg]] by 430.11 to convert to [[U.S. customary units|Btu]]/[[U.S. customary units|lb]].
|}

Revision as of 16:05, 2 May 2009

Retrieved from "https://citizendium.org/wiki/index.php?title=User:Milton_Beychok/Sandbox&oldid=386003"