Coal Chemical Analysis

[Azghaf]

I am trying to identify formulas for calculating Hydrogen%, NetCV and Carbon% from coal sample results (supplied Gross CV, Ash%, Volatiles%, Sulphur%, Chlorine% and Moisture%).

I am also looking for formulas for calculating CO2 Emissions gases (in tonnes) from fuel burnt chemical analysis.

Any assistance, including directions to further reading, would be greatly appreciated.

 

[Jdin]

In the absence of utlimate analysis, carbon and hydrogen content may be estimated using Seyler's Correlation:
C=0.95x((CV/41868)-((1.1xVM)/3))+0.434
H=0.069x((CV/41868)+VM)-0.0286
where C - carbon (%); H - hydrogen (%), VM - volatile matter (%) and CV calorific value (kJ/kg).

Net CV is Gross CV minus heat losses due to total moisture in complete combustion of 1kg of fuel. It will depend on the condition in which GCV was obtained and which standard you follow:

ASTM: NCV = GCV-((215.6xH)+(23.96xM)) at constant pressure
ISO: NCV=GCV-((206xH)+(23xM)) at constant volume
NCV = GCV -((212xH)+(0.8xO)+(24.5xM)) at constant pressure

CV in kJ/kg
H - hydrogen (%), O - oxygen (%), M - moisture (%)
<Beware of units they must be consistent>

WRT to CO2 emission you can obtain it from a flue gas monitor. If you don't have one, you'll need to know the combustion process (boiler efficiency or unit heat rates, etc.) and make some assumptions to derive an estimate.

The above is just &quot;back-of-envolope&quot; calculation and I'm sure there are someone who can provide a better solution.

 

[elliott66]

I may be misunderstanding your question, but here goes.

Formulas for converting from a ppm gas reading of the flue gas to a pounds/MBTU value for EPA reporting of emissions can be found in the 1992 EPA document on Stationary Sources. Using these formulas, you will need to identify the type of fuel burned to get the correct fuel factor and if the sample is on a wet or dry basis.

 

[25362]

I suggest you consult with Perry VI chapter 9, or any newer editions. One may find correlations of calorific values not only to ash%, and the presence of water, but also oxygen, nitrogen, sulphur, etc., and, of course, hydrogen and carbon.