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COAL BASICS
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As received basis (ARB) |
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Coal that includes TOTAL MOISTURE, ASH, VOLATILE MATTER, and FIXED CARBON |
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As dried basis (ADB) |
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Coal that includes INHERENT MOISTURE, ASH, VOLATILE MATTER, and FIXED CARBON |
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Dried basis |
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Coal that includes ASH, VOLATILE MATTER, and FIXED CARBON |
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Dried ash free basis |
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Coal that includes VOLATILE MATTER, and FIXED CARBON |
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VOLATILE MATTER |
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Gaseous products in coal excluding water vapou |
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ASH |
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Inorganic residue left after completely burning coal |
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Fixed carbon |
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solid portion other than ash present in coal 100- (IM+VM+ASH) |
CONVERSION FROM GAR TO NAR
The difference between net and gross as received (NAR v/s GAR) specific energy values is the latent heat of the water vapour which lowers the effective calorific value in the boiler.
To convert from GAR to NAR for bituminous coals subtract approximately
1.09 mj/kg
260 kcal/kg
470 btu/lb |