Question

Ethanol is produced commercially by hydration of ethylene and during this process a side reaction converts some the ethanol to diethyl ether (DEE).

In one process, a fresh feed containing ethylene, non-condensable inerts, and water are mixed with a recycle stream. The combined stream is fed to the reactor and it contains 182 mol/min of ethylene. While the fresh feed contains 9 moles of ethylene per mole of inerts, after mixing with recycle stream, the mole ratio of inerts to ethylene changes to 0.23. The water to ethylene mole ratio in the input to the reactor is 0.6. The single pass conversion of ethylene in the reactor is 0.23 and the molar selectivity of ethanol to ether is 14.

To recover the ethanol and DEE, the gaseous output from the reactor is sent to a condenser. Here, 93% of the three species - ethanol, DEE, and water - fed to the condenser are removed as a liquid product stream. None of the ethylene and inerts leave in the liquid. A second output from the condenser is the gas mixture and this is split into a purge and the recycle that mixes with the fresh feed.

Solve the material balance for the process and choose the correct option below.

A/ ethylene in fresh feed is 66.7 mol/min

B/ ethanol in product leaving the condenser is 41.6 mol/min

C/ recycle to purge ratio is 3.95

D/ Two choices, A and B, are correct

E/ The three A-B-C choices are all correct

Answer 1

Option A is the correct answer