Other Properties Heating Value
The heating value is obtained by combustion of the sample in a calorimeter. If not available, the heating value can be calculated with, for example, the Dulong formula (Perry and Chilton 1973, p. 9^4) from the ultimate analyses:
HHV in MJ/kg = 33.86*C + 144.4*(H-0/8) + 9.428*S
where С, H, O, and S are the mass fractions of the elements obtained from the ultimate analysis. There are other formulae for calculating the heating value from the ultimate and/or proximate analyses (e. g., Channiwala and Parikh 2002):
HHV in MJ/kg = 34.91 *C +117.83*H-10.34*0-1.51 *N+ 10.05*S-2.11 *Ash
It is always useful to calculate the heating value from these analyses, as it is a good crosscheck on measured values. If the deviation is more than a few percent, all analyses must be checked.