Question

Methane gas at 400K and 1 atm enters a combustion chambar where it is mixed with air entering at 500K, 1 atm. The products of combustion exit at 1800K and 1 atm with product analysis given in

For operation at steady state, determine the rate of the heat transfer from the combustion chamber in kJ/kmol of fuel. Neglect kinetic and potential energy effect . The average value for the specific heat of methane between 298 and 400K is 38kJ/molK. The balanced chemical equation is as follows:

CH4 + 2.265O2 + 8.515N2 ---> 0.951CO2 + 0.049CO + 0.289 O2 + 8.515N2 + 2H2O

Answer 1

The Cp data for the components is as follows

Cp/R = A +BT +CT2 + DT-2    Where T is in K from 298 oK

Name	Chemical formula	Tmax	CpigP298/R	A	B*103
Methane	CH4	1500	4.217	1.702	9.081
Carbon monoxide	CO	3000	3.507	3.376	0.557
Carbon dioxide	CO2	2500	4.467	5.457	1.045
Nitrogen	N2	2000	3.502	3.28	0.593
Oxygen	O2	2000	3.535	3.639	0.506
Water	H2O	2000	4.038	3.47	1.45

Enthalpy for all the components involved in above reaction is evaluted by the following General equation