A compression ignition engine operates with a liquid fuel that has an unspecified molecular formula C1HO. Analysis shows that the fuel contains 52% carbon, 13% hydrogen and 35% oxygen on a mass basis. Assume that no EGR is used. Emission test is conducted on this engine and the following measurements are collected:

Engine power	220 kW
Air flow rate	320 g/s
Excess air ratio	1.6
Tail-pipe NOx emissions	50 ppm by volume

Calculate the following and provide your answer in the indicated units: (1) The value of and in the fuel molecular formula (2) Stoichiometric air-fuel ratio (by mass) for the given fuel [-] (3) Fuel flow rate [g/s] (4) Power-based NOx emissions [g/kWh] (Hint: Assume air density is 1.29 kg/m3, power-based emission is defined as the mass of emission produced when the engine generates 1 kWh energy) To simplify question 4, let us assume NOx is all NO2 in the engine emission.

Another assumption can be made is that in the exhaust, all gaseous components can be treated as an ideal gas, hence:

Vi/v =ni/n = pi/p where Vi/v is the volumetric ratio of the gas component, ni/n is the mole fraction of the gas component, and Pi/p the

the pressure ratio of the gas component to the overall exhaust.

Also, HINT PROM PROFESSOR AS BELOW for the 4th question "For the last question, my suggestion is to utilize the hint | provided to derive the mole ratio of NOx in the exhaust.

Derive the mole exhaust flow rate using the information provided (note, exhaust volume does not equal to intake volume, need derivation), there are multiple ways to derive the exhaust mole, one is to assume it has similar properties as air."

My doubts - Since we dont know the Volume of the exhaust gas or mole fraction or exhaust flow rate ,how do we find the answer?? I might be wrong.. Please need a comprehensive explanation for the 4th part