Question

A sample of coal has the following composition by mass: C = 85%, H = 6%, O = 8%, S = 0.5% and Ash = 0.5%. Calculate HCV and LCV using Dulong’s Formula. Given Atomic Weights: C=12, H = 1, S = 32, O = 16

Answer 1

Dulong Formula

H.C.V = 1/100[8080C + 34500(H-O/8) + 2240S] kcal/kg

= 1/100[8080*85+34500*(6 – 8/8) + 2240*0.5]kcal/kg

= 1/100[ 860420]

=  8604.20kcal/kg

∴ H.C.V =8604.20kcal/kg

Low calorific value = H.C.V – [ 9H/100 *587]kcal/kg

= 8604.20 – [9*6/100*587]

=  8287.22  kcal/kg

LCV=8287.22 kcal/kg

Answer 2

using Dulong Formula