Iso-octane (C8H18) is produced in the reaction of isobutane (C4H10) and butylene (C4H8). The fresh feed has 10,000 mol/hr and contains 60 mol% isobutane and the rest butylene. The single pass conversion of isobutane is 30% and all of the butylene reacts in the reactor. The stream leaving the reactor then enters a flash separator. The liquid exiting the flash contains 74.3 mol% iso-octane and the rest isobutane. The vapor phase contains mostly isobutane but some iso-octane. Some of this stream is purged and the rest is recycled to meet the fresh feed. C4H10 + C4H8 → C8H18

Required:
a. Draw and label the diagram and put numbers where given.
b. Write out a SPICE table and calculate the number of moles of isobutane exiting the reactor.
c. The flash separator runs at 300 K. At this temperature, the saturation pressures of isobutane and iso-octane are 3.7 bar and 0.07 bar, respectively. Calculate the mole fraction of isobutane in the vapor phase leaving the flash.
d. Calculate the number of moles in the recycle stream. (Hint: start with the mass balance on isobutane on the mixing point of the fresh and recycle stream.)
e. Calculate the number of total moles in the vapor phase exiting the flash separator.
f. Calculate the number of moles of isobutane in the purge line.