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General Chemistry Principles, Patterns, and Applications, 2011

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Table 5.7 Properties of Different Types of Coal<br />

Type<br />

%<br />

Carbon<br />

Hydrogen:Carbon<br />

Mole Ratio<br />

%<br />

Oxygen<br />

%<br />

Sulfur<br />

Heat<br />

Content<br />

US Deposits<br />

anthracite 92 0.5 3 1 high<br />

bituminous 80 0.6 8 5 medium<br />

Pennsylvania, New<br />

York<br />

Appalachia,<br />

Midwest, Utah<br />

subbituminous 77 0.9 16 1 medium Rocky Mountains<br />

lignite 71 1.0 23 1 low Montana<br />

Table 5.8 Enthalpies of Combustion of Common Fuels <strong>and</strong> Selected Organic Compounds<br />

Fuel<br />

ΔHcomb (kJ/g)<br />

dry wood<br />

−15<br />

peat −20.8<br />

bituminous coal −28.3<br />

charcoal<br />

kerosene<br />

−35<br />

−37<br />

C6H6 (benzene) −41.8<br />

crude oil<br />

natural gas<br />

−43<br />

−50<br />

C2H2 (acetylene) −50.0<br />

CH4 (methane) −55.5<br />

gasoline<br />

hydrogen<br />

−84<br />

−143<br />

Peat, a precursor to coal, is the partially decayed remains of plants that grow in swampy areas. It is removed from the<br />

ground in the form of soggy bricks of mud that will not burn until they have been dried. Even though peat is a smoky,<br />

poor-burning fuel that gives off relatively little heat, humans have burned it since ancient times (Figure 5.20 "A<br />

Peat Bog"). If a peat bog were buried under many layers of sediment for a few million years, the peat could<br />

eventually be compressed <strong>and</strong> heated enough to become lignite, the lowest grade of coal; given enough time <strong>and</strong> heat,<br />

lignite would eventually become anthracite, a much better fuel.<br />

Converting Coal to Gaseous <strong>and</strong> Liquid Fuels<br />

Saylor URL: http://www.saylor.org/books<br />

Saylor.org<br />

480

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