Acetaldehyde (C2H4O) is produced by oxidation of ethane (C2H6):
C2H6 + O2 --> CH3CHO + H2O
Since air is supplied at 20% excess, two side reactions occur:
2C2H6 + 7O2 --> 4CO2 + 6H2O
2CH3CHO + O2 --> 2CH3COOH (acetic acid)
In a process to produce 1000 kgmol/h acetaldehyde, ethane is fed to the reactor at 1500 kgmol/h and the fractional conversion is 0.8. The product stream contains 2 mol% CO2. Calculate the molar composition of the product stream and the fractional selectivity of ethane to acetaldehyde. Assume that air is composed of 79 mol% N2 and 21 mol% O2.