100 mol/hr of methane reacts with steam to produce CO2 in a main reaction of the reformer. The amount of steam used is 12.5% excess based on this main reaction. Some of the methane is also converted to CO in the reformer. The total conversion of methane is 89.1% while the yield of CO2 is found to be 78%. The effluent from the reformer is sent to the converter where all of the CO is selectively burnt to CO2 in a stream of 8.6% excess air.
The resulting product stream from the converter is mixed with a fresh make-up feed of CO2 so that a molar ratio of 3 is obtained for H2 to CO2 in the mixed product. This mixed stream is then further combined with a recycle stream before entering the methanol synthesis reactor. In the methanol synthesis reactor, CO2 reacts with H2 to give methanol. A fractional conversion of 51.1% is achieved in a single pass of the reactor. The reactor product is sent to a condenser that separates all of the methanol and water from the other components. The aqueous methanol product contains only methanol and water while the second stream from the condenser contains the remaining components that are split into a purge and a recycle. This second stream is analyzed and found to contain 38.8 mol% nitrogen.
Solve the molar flow rates of all the components in the process and then choose the correct response from the choice below.
Answer
the recycle/purge mole ratio is 13.69
the make-up CO2 flow s 29.9 mol/h
mole ratio of CH3OH/water from condenser is 0.653
Two choices, A and B, are correct
The three A-B-C choices are all correct