BTU Calculation using % of elements (i.e. C, H, N) 2

[babybear]

I'm looking to find how to calculate the BTUs of a coal/coke sample if I have the %C, %H, and %N. I know it can be done, but I can't seem to find the equation. Thanks, and no it is not for homework, it's for my job.

 

[mbeychok]

babybear:

From Perry's Handbook (equation 9-7, page 9-5, 6th Edition):

Q = 146.58C + 568.78H + 29.4S - 6.58A - 51.53(O + N)

Q = Btu/lb
C = wt% carbon
H = wt% hydrogen
S = wt% sulfur
A = wt% ash
O = wt% oxygen
N = wt% nitrogen

The equation was developed by the Institute of Gas Technology. The standard deviation for 775 coal samples was 127.

Hope this helps.

Milton Beychok
(Visit me at www.air-dispersion.com)
.

 

[JLSeagull]

The following ASTM standards apply to calculating heating value:
ASTM D 3588 Standard Practice for Calculating Heat Value, Compressibility factor, and Relative Density of Gaseous Fuels
ASTM D 7174 Standard Practice for On-line/At-line Heating Value Determination of Gaseous Fuels by Gas Chromatography

 

[macmet]

I use the following equation from a book on natural and synthetic fuels,

HHV(kJ/g) = 0.3491*C + 1.1783*H + 0.1005*S - 0.1034*O - 0.0151*N - 0.0211*A

using weight % for C, H, S, O, N, Ash

It claims to be within 1.45% of tested results.

 

[25362]

A note: most formulas apply on a "dry" basis. For measuring the HHV of coal/coke specimens use ASTM D-5865-04.

 

[babybear]

These are all helpful, we are going to use these, but does anyone know how to do the proximate analysis w/o the ash% in it? Thanks for all your help so far.

 

[25362]

Both ASTM D-5142-04 and D-3172-89 (2002) are test for proximate analyses. What's wrong with them ?

 

[babybear]

I'll have to get a copy of those. We use ASTM C standards so I'll have to see if I can find a copy of the D standards. Thank you