Question

Calculate the gross and net calorific values of a coal sample having the following composition Carbon=80%,Hydrogen=7%,Oxygen=3%, Sulphur=3.5%, Nitrogen=2% and Ash=5%.

Answer 1

Answer:

Dulong's formula for calculating the calorific value is given as:

where C, H, O, and S are the percentages of carbon, hydrogen, oxygen and sulphur in the fuel respectively.

Formula for calculating the net calorific value:

C=80%, H=5%, O=4%, N=3%, S=3.5% and ash=5%.

Hence,

HCV = 0.01× [8080×80 + 34500×(5-4/8) + 2240×3.5] = 8094.9 kcal/kg

LCV = [8094.9 - 0.09×5×587] = 7830.75 kcal/kg

Answer: Net calorific value (LCV) of a coal is 7830.75 kcal/kg.