AZEOTROPIC DISTILLATION OF TOLUENE WITH

METHANOL

AZEOTROPIC DISTILLATION

a mixture form an azeotrope or close boiling mixture because the molecular interactions between them

a mixture of liquids that distil at isothermal condition but without change in composition are called azeotrope

azeotropic distillation method use to saparate the complex mixture (two azeotropic solvents) by entrainer.

(eg : toluene and methanol by using water or xylene as entrainer

INTRODUCTION

INTRODUCTION

Benefits of water as entrainer : i)very cheap ii) environment friendly iii) easily available iv) can be easily disposed

low positive concentration of entrainer used to remove solvent which is azeotrope

Can be done continously or batch- wise

AZEOTROPIC DISTILLATION

INTRODUCTION

Homogenous azeotropic distillation

alter relative volatility of two

azeotropic constituents without

inducing liquid-liquid phase saparation

Heterogenous azeotropic distillation

alter relative volatility and

inducing liquid- liquid phase saparation

TYPES OF AZEOTROPIC DISTILLATION

INTRODUCTION

INTRODUCTION

• saparation sequence cointains two column

• the first column called extractive column- breaks the azeotrope and yield the azeotropic constituents as the pure product

• the second column called entrainer recovery column-saparate the second azeotropic constituent from the entrainer which is recycled extractive column

BASED ON FIGURE 1.1

Objective of the

experiment

to investigate the various

waste stream that difficult

recovered with traditional

saparation and purification

process

to determine the displacement of

methanol and toluene azeotrope by using pervapouration or

extractive distillation

to study the vapor liquid equillibrium

(VLE) of methanol and toluene

to extablish industrial operating

conditions for the extractive distillation process of

methanol and toluene by using

water as entrainer

OBJECTIVE

PROBLEM STATEMENTthe complex mixture are not easy to saparate rather than

using the azeotropic distillation method

the relative volatility, ɑ of the mixture are too low at

whatever pressure- entrainer is introduce to

increase the relative volatility

recovering solvent which are expensive and large volume

needed for economic and enviromental benefits

THEORY Not all liquid mixtures follow Raoult’s Law Binary mixtures, which form azeotropes or close-boiling mixtures

are characterized as behaving like a pure component when submitted to a distillation process. Diagram 2.1 shows the vapor-liquid equillibrium (VLE) graph where the azeotrope occur.

Diagram 2.1 : Point F is the point where the azeotrope of mixture occurs

POINT F

THEORY• Function of entrainer: To

METHODOLOGY

Clean the 4 neck round bottom glass flask

Put into the heating mental

Connect the vertical packed column in on the glass flask

Put thermometer in the thermo well and this thermo- well insert in one ef the neck of the

glassConnect top vapour outlet in glass coiled type

condensor, connect second condensor in series, connect the coolling water in primary and chilliing water in the secondary condensor connect flask to

condensate collection oulet

GENERAL START-UP PROCEDURE

METHODOLOGYPROCEDURE FOR DISTILLATION

Charge 3500ml to 4000ml of spent solvent mixture into the 5000ml into the four necks round bottom

glass flaskSend the sample for analyzing content, moisture and

specific gravity

Apply the cooling water in primary condensor and chill water in secondary condensor

Start heating and keep the solvent under reflux for 30-60 minutes

Start collection of first fraction (toluene) from the top column, at the same time feed the water (entrainer) from the top of the column

METHODOLOGYPROCEDURE FOR DISTILLATION

After collecting toluene fraction send the sample for complete analysis by GC

Stop feeding water from the top fractionation column

Start collection of second fraction (methanol) from the top column

Keep the reflux ratio 1:3

Check the water content of methanol ( in process analysis), after collecting and saparating methanol fraction completely, stop heating and cool the remaining residue, unload residue and measure it.

METHODOLOGYEXPERIMENTAL SET-UP

METHODOLOGY