Tutorial 2
Q.1 1.5 g of a coal sample is kept in the bomb of a calorimeter. The initial and final temperatures of water
in bucket are 23 and 28 0C respectively. The bucket wash is titrated against N/10 Na2CO3 and the titer value
is 2.5 ml. Sulphur content in the coal is 2 %. Parr 45C10 Ni-Cr wire is used to ignite the coal sample and
4 cm of the wire is fused. The water equivalent of the calorimeter is 2402 cal per oC. Hydrogen content of
the coal sample is 8 %. Calculate the HHV and LHV of the coal sample.
Q.2 To determine the water equivalent of a bomb calorimeter 1.1651 gram benzoic acid sample (HHV 6318
cal/g) was used. The experiment produced a net corrected temperature rise of 3.077 o C. The acid titration
required 11.9 ml of standard alkali and 8 cm of Parr 45C10 nickel-chromium fuse wire was consumed in
the firing. Determine the water equivalent of the bomb calorimeter.
Q.3 The composition of flue gas (dry basis) from an incinerator is as follows:
12.3% CO2, 5.1% O2, and the rest is nitrogen. From these data, calculate:
➢ The weight ratio of hydrogen to carbon in the coal sample
➢ The percent carbon and hydrogen in the dry coal sample
➢ The percent excess air used
➢ The moles of exhaust gas discharged from the unit per kilogram dry coal burnt
Q.4 A coal has the following composition on mass basis:
C: 70.5 (%), H: 4.8 %, O: 5 %, N:0.40 %, S:0.7%, Moisture: 11% and Ash:7.6%. Assume average molecular
weight of ash is 56.
If this coal sample is incinerated in fixed bed inclinator what will be the composition of the flue gas if 20
% excess air is supplied?