Calculate weight of air needed for complete combustion of 2kg of coal containing C=70%, H=10%, O=10%, N=5% and remaining ash.
1kg of coal contains 0.7kg C,0.1kg H & 0.1kg O2
|Combustion reactions||Weight of O2 required(kg)|
|1) C + O → CO2||`0.7xx32/12=1.86`|
|2) H2+12O2 → H2O||`0.1xx16/1=0.8`|
Weight of O2 = 1.86+0.8=2.66
Available O2 = 0.10
Total O2 = 2.56
Air contains 23% O2 by weight
∴Min quantity of air required = 2.56`xx100/23`
= 11.13 kg.
For 2kg of coal air needed = 11.32 × 2