Methanol is synthesized from carbon monoxide and hydrogen in a catalytic reactor. The fresh feed to the process contains 32.0 mole% CO. 64.0% H2 and 4.0% N2. This stream is mixed with a recycle stream in a ratio 5mol recycle/i mol fresh feed to produce the feed to the reactor, which contains 13.0 mole% N2. A low single-pass conversion is attained in the reactor. The reactor effluent goes to a condenser from which two streams emerge: a liquid product stream containing essentially all the methanol formed in the reactor and a gas stream containing all the CO H2 and N2 leaves the reactor. The gas stream is split into two fractions: one is removed from the process as a purge stream, and the other is the recycle stream that combines with the fresh feed to the reactor. (a) For a basis of 100 mol fresh feed/h. calculate the production rate of methanol (mol/h), the molar flow rate and composition of the purge gas, and the overall and single-pass conversions.
(b) Briefly explain in your own words the reasons for including (i) the recycle stream and (ii) the purge stream in the process design.