5. In a boiler furnace, a natural gas includes 85% $CH_4$, balanced with $C_2H_6$.
is burned with 25% excess dry air. The entering temperatures of natural gas
and dry air are 25°C and 120°C, respectively. When the complete
combustion occurs, calculate the adiabatic flame temperature.
$C_{p,mean}$ (J/molK)
$O_2$ 29.44
$N_2$ 29.3
$CO_2$ 37.35
$H_2O(v)$ 38.5
$\Delta \hat{H}_c^° (\frac{kJ}{mol}$, as $H_2O(l))$
$CH_4(g)$ -890
$C_2H_6(g)$ -1559.9
For water: $\Delta \hat{H}_v^° = 44 kJ/mol$
