KKKR1034 FUNDAMENTAL OF CHEMICAL AND BIOCHEMICAL ENGINEERING Chemical and Biochemical Engineering Department REPORT TITLE: PFD study of the Production of Isopropyl Alcohol. LECTURER’S NAME: 1. PROF. ABU BAKAR BIN MOHAMAD 2. DR. MANAL BINTI ISMAIL Group Members Matric no. CHONG KIN HOW A130043 MOHD AZIZAN BIN RAZAL @ ABD RAZI A130463 NORFATYHAH BINTI ABD. AZIZ A130473 NORASMANIRA BINTI MUSA A129780 NUR IZAYU BINTI BADARUDDIN A127653 DATE OF SUBMISSION: 1 st JUNE 2010
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KKKR1034 - Open Minded · PDF fileTABLE OF CONTENT No. Item Page 1 Introduction 1.1 Physical properties of IPA 1.2 Chemical properties of IPA 1.3 Production of IPA 1.4 Uses and
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KKKR1034
FUNDAMENTAL OF CHEMICAL AND
BIOCHEMICAL ENGINEERING
Chemical and Biochemical Engineering Department
REPORT TITLE:
PFD study of the Production of Isopropyl Alcohol.
LECTURER’S NAME:
1. PROF. ABU BAKAR BIN MOHAMAD
2. DR. MANAL BINTI ISMAIL
Group Members Matric no.
CHONG KIN HOW A130043
MOHD AZIZAN BIN RAZAL @ ABD RAZI A130463
NORFATYHAH BINTI ABD. AZIZ A130473
NORASMANIRA BINTI MUSA A129780
NUR IZAYU BINTI BADARUDDIN A127653
DATE OF SUBMISSION:
1st JUNE 2010
ABSTRACT
The objective of the report is to study the process of production of isopropyl alcohol
by using indirect hydration method. An improved process for indirect hydration of propylene
to form Diisopropyl Ether and Isopropyl Alcohol is provided in which propylene is absorbed
in Sulphuric acid to form an extract. It is withdrawn from the absorbing zone; water in
carefully controlled amounts is mixed with the extract. While the resulting mixture is passed
to an ether generating zone to form a vaporous ether product and a bottoms product depleted
in Diisopropyl Ether containing Sulphuric acid in a concentration at least equal to the acid
concentration in the extract withdrawn from the absorbing zone. The withdrawn bottoms is
the divided into two portions: a first portion is recycled to the absorber; and the second such
portion is mixed with sufficient water to hydrate absorbed olefin values and the resulting
mixture is fed to an alcohol generator for formation of isopropyl alcohol as overhead product
and dilute Sulphuric acid as bottoms product.
TABLE OF CONTENT
No. Item Page
1 Introduction
1.1 Physical properties of IPA
1.2 Chemical properties of IPA
1.3 Production of IPA
1.4 Uses and application of IPA
1.5 Health and Safety Factor
1.6 Isopropyl Alcohol nowadays
2
2
3
5
7
7
2 Process Flow Diagram (PFD)
2.1 Block diagram of production of Isopropyl alcohol
2.2 Process Flow Diagram of production of IPA
2.3 Description of process flow diagram of production of IPA
8
9
11
3 Conclusions
15
4 References
17
INTRODUCTION
The IUPAC name for chemical compound with the molecular formula of C3H8O is
propan-2-ol. Other common names for this compound are isopropyl alcohol, isopropanol, 2-
propanol and rubbing alcohol. It is the simplest example of a secondary alcohol which the
hydroxyl group (OH-) is attached to a carbon atom that is also attached to two other carbon
atoms sometimes shown as (CH3)2CHOH. Besides, it is a structural isomer of propanol and in
industry, the isopropyl alcohol is well known as IPA.
1.1. Physical Properties of IPA
Some of the physical properties of isopropyl alcohol are it is colorless liquid at room
temperature, the molar mass is approximately 60.09 g mol−1
, have strong rubbing alcohol
odor, miscible in water, soluble in some organic solvent but insoluble in salt solution and it is
also fairly volatile (evaporates easily). The melting point of this chemical compound is -890C
whereas the boiling point is 82.50C. Anhydrous IPA has density about 0.7854g/cm
3 whereas
the 91% vol IPA have a density of 0.8173 g/cm3.
1.2. Chemical properties of IPA
Chemical properties of isopropyl alcohol are determined by its functional hydroxyl group
in the secondary position. Except for the production of acetone, most isopropyl alcohol
chemistry involves the introduction of the isopropyl or isopropoxy group into other organic
molecules by the breaking of the C–OH or the O–H bonding the isopropyl alcohol molecule.
Isopropyl alcohol undergoes reactions typical of an active secondary alcohol. Some of the
chemical property of this alcohol is it can be separated from its aqueous solutions by adding a
salt such as sodium chloride, potassium chloride, or any of several other inorganic salts. This
is due to solubility of this alcohol in saline which is less compared to its solubility in salt-free
water.
Besides, IPA may undergo dehydrogenation process. Dehydrogenation of isopropyl
alcohol to acetone was the most widely practiced production method in industry. This
reaction is endothermic reaction means it absorbs about 66.5kJ/mol of heat and occurs at
temperature range between 300-5000C. The most useful catalyst contains Cu, Zn, Cr, and Ni
as oxides can be used to increase the reaction rate. The balance chemical equation of the
dehydrogenation process:
(CH3)2CHOH → CH3COCH3 + H2
Chemically, secondary alcohol can be catalytically oxidized using air or oxygen at
high temperature (400−600◦C) to form respectively ketone and water. Here, when isopropyl
alcohol undergoes oxidation process, the product is acetone. The preferred catalyst for this
reaction is zinc chloride, ZnO. The oxidation process is highly exothermic which means this
reaction releases large amount of energy usually in the form of heat
(CH3)2CHOH + 0.5O2 → CH3COCH3 + H2O
Furthermore IPA reacts with active metal such as potassium to form alkoxides. Next,
isopropyl alcohol can be dehydrated in either the liquid phase over acidic catalysts, eg,
sulfuric acid, or in the vapor phase over acidic aluminas to give diisopropyl ether. This
reaction is known as etherification.
IPA also undergoes halogenation chemical reaction with halogen compound.
Normally, 2-halopropane derivatives are prepared from isopropyl alcohol most economically
by reaction with the corresponding acid halide. However, under appropriate conditions, other
reagents, eg, phosphorus halides and elemental halogen also react by replacement of the
hydroxyl group to give the halide. Normally, this reaction temperature is about 650C.
3(CH3)2CHOH + PBr3 → (CH3)2CHBr + H3PO3
1.3.Production of IPA
In industry, many methods can be carried out to produce isopropyl alcohol. The
hydrolysis of haloalkanes is one of the examples. Here, a secondary haloalkane is used for
instance 2-bromopropane. This haloalkane is than being reacted with an aqueous solution of
base or alkali (e.g: sodium hydroxide, NaOH). The product of this reaction is secondary
alcohol and halide ion in this case the isopropyl alcohol and bromide ion. Other technique is
by the addition of Grignard Reagent to carbonyl compound.
But chemically, the most beneficial way usually being performed to produce isopropyl
alcohol in large amount is by hydration process. In general, hydration reaction is a chemical
reaction in which a hydroxyl group (OH-) and a hydrogen cation are added to the
100-200kPa
acetone
2-halopropane
two carbon atoms bonded together in the carbon-carbon double bond which makes up
an alkene functional group. In order to obtain isopropyl alcohol as the major product, an
alkene called propene is used.
There are two processes to produce isopropyl alcohol by combining water and propene.
One is direct hydration by reacting propene-containing hydrocarbon stream with water either
in gas or liquid phases at high pressures with the presence of a strongly heterogeneous
polymeric acid, solid hydration catalyst, preferably a cation exchange resin catalyst. The
catalyst is used to increase the rate of reaction but the catalyst itself do not consumed in the
reaction. Since the addition of sulphuric acid or water to propene follow Markovnikov’s rule
which state that when a molecule HX is added across a carbon-carbon double bond, the
hydrogen ion from HX will joins to the carbon atom which is already has the more hydrogen
atoms attached to it, this process give propan-2-ol as the main product rather than 1-propanol
that will be the side product. This process requires high-quality propene than is represented
by simple chemical equation follow:
CH3CH=CH2 + H2O ↔ CH3CH(OH)CH3
Second method is indirect hydration with sulfuric acid. This is the most common
route to produce IPA. The alkene is hydrated to alcohols by a two stage process. First stage is
the process of reacting propene with sulphuric acid to form a mixture of sulphate esters
named isopropyl hydrogen sulphate and diisopropyl sulfate. It can be said that the sulphuric
acid will be functioning as catalyst. The esterification of propene with sulphuric acid is
conducted in apparatus called absorber and takes place at low temperature, usually below
70°C. This process is corrosive and is energy demanding for acid re-concentration and
aqueous waste treatment. The chemical reactions occur is represented by balanced chemical
equation:
CH3CH=CH2 + H2SO4 → (CH3)2CHOSO3H
(CH3)2CHOSO3 + CH3CH=CH2 → ((CH3)2CH)2SO2
And the final stage is the hydrolysis of these esters to produces isopropyl alcohol. The
hydrolysis process occurs in which a certain molecule is split into two parts by the addition of
diisopropyl sulfate
Isopropyl hydrogen
sulphate
a molecule of water. Here, the addition of water to the mixture of isopropyl sulphate and
diisopropyl sulfate yield IPA and sulphuric acids respectively. The machine in which the
hydrolysis process is conducted is known as hydrolyzers. As with the direct hydration
method, some byproducts are either being recycle or set aside.