Experiment 1Batch Report

Objectives of Experiment

To determine the reaction rate of saponification reaction at given temperature by measuring the conversion against reaction time, evaluate the reaction rate constant at constant temperature using differential and integral methods of analysis and the rate constant at different temperature and activation energy determination from Arrhenius Plot.

Introduction

TheBatch reactoris the generic term for a type ofvesselwidely used in the process industries. Its name is something of amisnomersince vessels of this type are used for a variety of process operations such assolids dissolution,product mixing,chemical reactions,batch distillation, crystallization, liquid/liquid extraction andpolymerization. A typical batch reactor consists of atankwith anagitatorand integral heating/cooling system. Liquidsandsolidsare usually charged via connections in the top cover of the reactor. Vapors andgasesalso discharge through connections in the top. Liquids are usually discharged out of the bottom.Batch chemical process is a discontinuous process, which has neither inflow nor outflow of reactants or products while the reaction is being carried out. Thus the mass balance equation for species A in an element of reactor volume V obeys the following statement:

Rate of A produced within volume element = Rate of A accumulated within volume element

In this experiment, the reaction to be studied is the saponification of ethyl acetate Et (Ac) and sodium hydroxide NaOH. The reaction is shown in following equation.

TheoryThere is no inflow and outflow in the batch reactor. Thus, the mole balance for component j is reduced as equation below:

Rate of accumulation of j (moles/time) =Rate of generation of j (moles/time)

= rjV

Suppose the conversion of component j in constant volume system is given by

Where,Nj0 = initial amount of j at t = 0

Nj = present amount at time t

When disappearance of component of j, the equation can be express as following,

By integrating the equation above,

Since,

Therefore the time t necessary to achieve a conversion in term of concentration can be express as below,

If the density of the fluid remains constant,

Equation 4.7 can be shown graphically,

Graph of reaction rate versus concentrations

The Arrhenius Equation is given by

WhereA = pre-exponential factor of frequency factor

E = activation energy, kJ/mol or cal/mol

MATERIALS AND EQUPMENT

1. Batch reactor apparatus

2. Beakers

3. Stirrers

4. Water bath

5. Stopwatch

6. 1 L of 0.1 M sodium hydroxide, NaOH

7. 1 L of 0.1 M ethyl acetate, Et(Ac)

8. 1 L of 0.1 M sodium acetate, Na(Ac)

9. 1 L of deionised water, H2ODIAGRAM

Figure 1 : Batch ReactorC j

C jo

C j