Octane (C8H18) Is combusted with excess air. The product gas composition is partially known. The dry gas compositions of octane and carbon dioxide are: Octane mole fraction - 0.0062
Carbon dioxide mole fraction - 0.0455
What is the percent excess air fed to the combustor? Assume combustion is complete and use a basis of 100 mol/h of the dry gas (stream 4 below) for your calculations. Note the reaction below is not balanced. Report answer to three sig figs.
n3
yOce
1 Combustor W=
Oc+02 = CO2+W
ni
W = H20
Ốc -CEH18
0.21
0.79
n2
YO2=
yN2=
109
nd-
yoc
yCO2
YO2
YN2

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.