Question

A liq mixture of benzene-toluene is to be distilled in a fractionating tower at 101.3 kPa pressure. The feed of 100 kg mol/h is liq and it contains 45 mole % benzene and 55 mole % toluene and enters at 327.6 K (130 ^◦F). A distillate containing 95 mole % benzene and 5 mole % toluene and a bottoms containing 10 mole % benzene and 90 mole % toluene are to be obtained. The reflux ratio is 4:1. The average heat capacity of the feed is 159 kJ/ kg mol – K and the average latent heat 32099 kJ/ kg mol. Calculate the kg moles per hour distillate, the kg moles per hour bottoms and the number of theoretical trays needed. The equilibrium and the vapor - pressure data are given below for the system benzene-toluene.

Make a list of all the important assumptions you are making in your calculations.

Note: All plots must be done either by using Excel or on a graph paper.

Mole % Benzene at 101.325 kPa

x    y

1.000 1.000

0.780 0.900

0.581 0.777

0.411 0.632

0.258 0.456

0.130 0.261

0 0

Vapor Pressure

Benzene Toluene

T(K)	T (°C)	kPa	mm Hg	kPa	Mm Hg
353	80.1	101.3	760
358	85	116.9	877	46.0	345
363	90	135.5	1016	54.0	405
368	95	155.7	1168	63.3	475
373 378	100 105	179.2 204.2	1344 1532	74.3 86.0	557 645

Answer 1

using Mcabe theile assumptiona and saturated liquid feed we can find the equation for enriching and stripping section and mass balance to find molar flowrates

for any clarification on solution please write in comments i ll respond ASAP