Methanol is produced by reacting carbon monoxide and hydrogen. A fresh feed stream containing CO and H2 joins a recycle stream and the combined stream is fed to a reactor. The reactor outlet stream flows at a rate of 350 mol/min and contains 10.6 wt% H2, 64.0 wt% CO, and 25.4 wt% CH3OH. (Notice that those are percentages by mass, not mole percents.) This stream enters a cooler in which most of the methanol is condensed. The liquid methanol condensate is withdrawn as a product, and the gas stream leaving the condenserwhich contains CO, H2, and 0.40 mole% uncondensed CH3OH vaporis the recycle stream that combines with the fresh feed.

(a) Without doing any calculations, prove that you have enough information to determine (i) the molar flow rates of CO and H2 in the fresh feed, (ii) the production rate of liquid methanol, and (iii) the single-pass and overall conversions of carbon monoxide. Then perform the calculations.

(b) After several months of operation, the flow rate of liquid methanol leaving the condenser begins to decrease. List at least three possible explanations of this behavior and state how you might check the validity of each one. (What would you measure and what would you expect to find if the explanation is valid?)

(solution to a) n = 5:28 106 lb-mol gas