Chapter One : Literature Review
Chapter One
Literature Review
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Chapter One : Literature Review
1.1. Definition of acetone
Acetone is a colorless liquid with a distinctive taste and ‘fruity’ odour.
- Formula: (CH₃COCH₃ (
- Molecular Weight: 58.079 g/mol.
- Chemical structure
Acetone is the simplest and most important of the ketones. It is a colorless,
mobile flammable liquid with a mildly pungent and somewhat aromatic odor.
It is miscible in all proportions with water and with organic solvents such as
diethyl ether, methanol, ethyl alcohol, and esters. It is used as solvent for
cellulose acetate and nitro cellulose , as a carrier for acetylene , and as a raw
material for the chemical synthesis of a wide range of products ketone ,di-
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Chapter One : Literature Review
acetone alcohol, methyl isobutyl Ketone, hexylene glycol (2-methyl-2, 4-
pentanediol).
1.2 Historical Background
Until World War I, acetone was manufactured by the dry distillation of calcium
acetate, which was obtained by neutralizing pyro ligneous acid with lime and
evaporating to dryness. When World War I began, new methods of manufacture
were explored. Calcium acetate could be made from acetic acid which had been
produced by fermentation of alcohol or from acetylene. However, this method
could not compete with the fermentation process developed by Weizmann and
Hamlyn for the conversion of carbohydrate to acetone and butyl and ethyl alcohol
by use of a special bacillus. Publicker Industries, Commercial Solvents, and
National Distillers, at one time, had combined bio-fermentation process acetone
capacity of 22,700 metric tons per year.
This method, in turn, became non-competitive in the late 1950s and early 1960s
owing to the economics of scale of the cumene hydro-peroxide-to-phenol and the
isopropyl alcohol dehydrogenation processes. Production of acetone by
dehydrogenation of isopropyl alcohol actually began in the early 1920s.
It remained the dominant production method through the sixties, in 1976, 60% of
United States acetone capacity was based on cumene hydro-peroxide. In 1974,
about 65% of the acetone produced was via the cumene hydro-peroxide process.
The process for direct oxidation of propylene to acetone was developed in the
early to middle1960s. However, this technology is not known to be in use in the
United States .In the middle 1960s, virtually all United States acetone was
produced from propylene. The two important routes in the United States to
acetone are cumene hydro peroxide cleavage and dehydrogenation of isopropyl
alcohol. An undefined minor portion of the acetone from isopropyl alcohol is
produced by catalytic oxidation.
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1.3 Acetone properties
It is colourless, mobile, flammable liquid with a mildly pungent and somewhat
aromatic odor. It is miscible in all proportions with water and with organic
solvents such as ether, methanol, ethyl alcohol, and esters. Acetone is used as a
solvent for cellulose acetate and nitrocellulose, as a such ketone , hexylene
glycol(2-methyl-2,4-pentanediol), and isophorone carrier for acetylene and as raw
material for the chemical synthesis of a wide range of products as ketene, methyl
methacrylate.
1.3.1 Physical properties
Property Value
Formula O
Melting point, -94.6
Appearance Colorless liquid
Molar mass, 58.08
Density, 0.791
Viscosity at 10 , mPa.s 0.36
Flash point -20 (-4 ;738 )
Boiling point at 1 atm, 56.1
Specific heat of liquid, J/g.k 2.6
Electrical conductivity at 25 , S/Cm 5.5*
Heat of Vaporization, kJ/mol 29.1
Specific heat of vapor, J/(mol.k) 92.1
Heat of combustion of liquid, kJ/mol 1787
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Chapter One : Literature Review
Heat of formation gas at 25 , kJ/mol -216.5
Heat of formation liquid at 25 , kJ/mol -248
Entropy of liquid at 298.15k , J/k 200.1
Acidity 19.2
Basicity -5.2
Explosive limits 2.6-12.8%
Molar entropy, J/mol.K 200.4
Refractive index 1.359
1.3.2 Chemical Properties
Acetone has closed-cup flash point of -18 and an auto ignition temperature of
538 The explosive limits of acetone-air mixtures lie between 2.15 and 13.o vol %
acetone in air at 25 Acetone shows the typical reactions of saturated aliphatic
ketones. It forms crystalline compounds with alkali bisulfiteswith sodium bio
sulphate, the compound is obtained. Reducing agents
converts convert acetone to isopropyl alcohol and pinacol. Propane is the product
of the Clemmensen reduction:
Isopropyl amine is produced by reductive ammonolysis of acetone:
At catalyst and 100-500 kpa
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Acetone undergoes much condensation reaction. For example, condensation with
amines will yield Schiff bases. Orthoformic esters condense with acetone to form
acetyls. With hydrogen sulfide, acetone reacts to form thioketone in presence of
an amine, or ammonia, various esters condense readily with acetone. In the
presence of sodium alkoxides and sodium amide, β-diketones are formed. It is
also possible to produce β-diketones by reaction of acetone with carboxylic
anhydrides in the presence of boron tri-fluoride.
Acetone is stable to many of the usual oxidants, such as silver nitrate, cold nitric
acid, and neutral potassium permanganate, but it can be oxidized with some of
the stronger oxidants such as alkaline potassium permanganate, chromic acid, hot
nitric acid. Acetone can also be oxidized by an alkali metal hypohalite or by
halogen in the presence of a base, to a halo-form and alkali metal acetate.
1.4 Uses of acetone
1.4.1 Feed stock
The important industrial use for acetone involves its reaction with phenol for the
manufacture of bisphenol A.
Bisphenol A is an important component of many polymers such as
polycarbonates, polyurethanes and epoxy resins. Acetone has also been used in
the manufacture of cordite.
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1.4.2 Cleaning fluid
Acetone is after the primary (or only) component in nail polish remover .Ethyl
acetate, another organic solvent, is sometimes used as will. Acetone is also used
as a superglue remover .It can be used for thinning and cleaning fiber glass resins
and epoxies. It is a strong solvent for most plastics and synthetic fiber. It is ideal
for thinning fiber glass resin, cleaning fiber glass tools and dissolving two-part
epoxies and superglue before hardening. A heavy-duty degreases, it is useful in
the preparation of metal prior to painting; it also thins polyester resins, vinyl and
adhesives. It easily removes residues from glass and porcelain. In biological
research contexts, buffers that contain acetone (such as citrate-buffered
formalin) use the acetone to lyses cells for further experimentation.
1.4.3 Solvent Acetone
can also dissolve many plastic, including those used in Nalgene bottles made of
polystyrene, polycarbonate and some types of polypropylene. In the laboratory,
acetone is used as a polar aprotic solvent in a variety of organic reactions.
Acetone is also used extensively for the safe transporting and storing of acetylene
in the mining industry. Vessels containing a porous material are first filled with
acetone followed by acetylene, which dissolves in to the acetone. One litre of
acetone can dissolve around 250 liters of acetylene.
1.4.4 Medical uses
Acetone is used in a variety of general medial and cosmetic applications and is
also listed as a component in food additives and food packaging. Dermatologists
use acetone with alcohol for acne treatments to peel dry skin. Acetone is
commonly used in chemical peeling. Common agents used today for chemical
peels are salicylic acid, glycolic acid, 30% salicylic acid in ethanol acid . Prior to
chemefoliation, the skin is cleaned and excess fat removed in a process called
defatting. Acetone, Skeptical, or a combination of these agents is commonly used
in this process.
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1.4.5 Other uses
Acetone is also used as drying agent, due to the readiness with which it mixes
with water. It can be used as an artistic agent; when tubed on the back of a laser
print or photocopy placed face-down on another surface and burnished firmly,
the toner of the image is allowed to the destination surface.
1.5 Analysis and storage
Acetone can be determined by treating with hydroxylamine hydrochloride and
titrating the liberated hydrochloric acid. The formation of idol form from the
reaction of acetone with iodine (hypo iodate) is the basis of another useful
method of analysis. The excess iodine is titrated, and the amount which has
reacted with the acetone is thus determined by difference. In current industrial
practice, gas chromatography is also widely used, especially for quality control
purposes. The chief impurity in acetone is usually few tenths of one percent of
water. Acetone contains no oxidizable impurities, and the color of a few drops of
permanganate is retained for several hours. Other test methods were covered in
the previous section. Since acetone, as commercially produced today, is virtually a
pure product, common practice is to store the product in steel tanks. Acetone is
also transported in steel drums, tank trucks, and rail cars.
1.6 Metabolism of acetone
1.6.1 Biosynthesis
Small amounts of acetone are produced in the body by the decarboxylation of
ketone bodies. Certain dietary patterns, including prolonged fasting and high-fat
low-carbohydrate dieting, can produce ketosis, in which acetone is formed in
body tissue. Certain health conditions, such as alcoholism and diabetes, can
produce ketoacidosis, uncontrollable ketosis that leads to a sharp, and potentially
fatal, increase in the acidity of the blood. Since it is a by-product of fermentation,
acetone is a by-product of the distillery industry.
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1.6.2 Metabolic use
Although some biochemistry textbooks and current research publications indicate
that acetone cannot be metabolized, there is evidence to the contrary some
dating back thirty years. Acetone can be produced from the oxidation of ingested
isopropanol, or from the spontaneous/enzymatic breakdown of acetoacetate (a
ketone body) in kenotic individuals. It can then be metabolized either by CYP2E1
via methyl-glyoxal to D-Lactate and pyruvate, and ultimately glucose/energy, or
by a different pathway via propylene glycol to pyruvate, lactate, acetate (usable
of energy) and propionaldehyde.
1.7 Acetone Manufacturing Process
1.7.1 Direct oxidation of propene
The most elegant method for manufacturing acetone, which has been practiced
commercially since1964 .in this liquid phase process, propene is oxidized to
acetone with air at 110-120 and 10-14 bar in the presence of catalyst system
contain (Pdcl2):
CO
The selectivity to acetone the main product is 92%, The conversion of propene is
more than 99% as in the oxidation of ethylene to a acetaldehyde (PdCl2) is
reduced to (Pd) in a stoichiometric reaction.
1.7.2 Co-production in Hock Phenol process
Benzene is alkylated to cumene is oxidized to cumene Hydro peroxide which in
turn is cleaved to phenol and acetone:
Over 90% of phenol product in the USA is via the cumene per oxidation one kg of
phenol production will result in 0.6 kg of acetone. The process steps are:
oxidation of cumene to a concentrated hydro peroxide cleavage of the hydro
peroxide neutralization of the cleaved and distillation to recover acetone. The
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Chapter One : Literature Review
Temperature is generally between 80 and 130. A typical process involves the use
of three or four cumene oxidation reaction in series. The temperature from a high
of 115 in the first reactor, to 90 for the last reactor. This procedure may result in
concentration of cumene hydro peroxide of 9-12% in reactor 15-20% in reactor
and 32-39% in reactor . Yields of cumene hydro peroxide may be in range of 90-
95%. The total residence time in each reactor is likely to be in range of 3-6hr. The
product is then concentrated by evaporation to 75-85% cumene hydro peroxide.
The cleavage reaction occurs under acid conditions in agitated vessel at 60 -100 ,
a large number of non-oxidizing in organic acids are useful for this reaction. At
this point, the reaction mass is a mix of phenols acetone, and a wide variety of
other products such as cumylphenols, a cetophenone dimethyl phenol carbine,
and methyl styrene. It may be neutralized with a sodium peroxide solution.
Process water be added to facilitate removed of any inorganic salts; the product
may then go through a separation and a wash stage or go directly to a distillation
tower.
1.7.3 Old method
Previously, acetone was produced by the dry distillation of acetone, for example
calcium acetate in kenotic decarboxylation.
Ca + +
1.7.4 Dehydrogenation of Isopropanol
Catalytic dehydrogenation of isopropanol can be chosen as alternative
applications. Tartan et.al. Mentions that a single pass conversion of 85-92% with
respect to isopropanol, with reactor conditions of 2 bar and 350° C, is generally
achieved synthetic route when high-purity acetone is required, such as in
biomedical. A molten salt stream will be used a heat source for the endothermic
reaction:
(1)
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The acetone produced in the reactor passes into a phase separator and then into
a separation system that includes one stripping and two distillation columns. A
recycle stream takes a mixture of unreacted isopropyl alcohol and water, with a
trace amount of acetone, back into a mixer that feeds the reaction system. Using
the catalyst which will be employed throughout this analysis, the reaction is first
order with respect to the concentration of isopropanol and has an Arrhenius
dependence on temperature with E=72.38 MJ/kmol and k=351,000 cubic m
gas/cubic m reactor sec. The acetone produced in the reactor passes into a phase
separator and then into a separation system that includes one stripping and two
distillation columns. A recycle stream takes a mixture of unreacted isopropyl
alcohol and water, with a trace amount of acetone, back into a mixer that feeds
the reaction system. Using the catalyst which will be employed throughout this
analysis, the reaction is first order with respect to the concentration of
isopropanol and has an Arrhenius dependence on temperature with E=72.38
MJ/kmole and k=351,000 cubic m gas/cubic
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8.1 Description of the process
8.1.1 Description of the process of acetone1
-At the beginning of the process, feed including i-propyl alcohol and water, and
recycle stream are mixed in feed drum.
-From here, this mixture is send to vaporizer to change stream’s phase as vapor.
after vaporizer, mixture is heated to reaction temperature in the heater.
- Reactor used is a tubular flow reactor. Acetone, hydrogen gas (H2) are produced
and water and i-propyl-alcohol are discharged. The mixture which are acetone,
hydrogen, water, i- propyl-alcohol are sent to cooler and then to condenser.
- After condenser the mixture is sent to flash unit. Hydrogen, acetone, ipropyl-
alcohol and water are obtained as top product.
- This top product is sent to scrubber to remove hydrogen. The bottom product of
flash unit which is consist of acetone, water, i-propyl-alcohol are mixed with the
bottom product of scrubber before acetone column.
- In acetone column, acetone is obtained from top product with 99 wt%. İ-propyl
alcohol and water and also 0, 1% of acetone is sent to I propyl-alcohol column
from bottom product.
- The top product of this column is sent to feed drum and bottom product is
thrown away as waste water.
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1.8.2 Description of the process of aceton2
- First, Isopropanol is heated using steam to vaporize the same .
- Then, Isopropanol is compressed to desired reactor pressure i.e., 4 – 5 atm.
- The compressed Isopropanol then enters a catalytic shell and tube reactor in the
tube side. The tube is packed with the porous copper catalyst.
- The reactor is operated at 400 – 500C using flue gas for heating. The flue gas is
passed in the shell side of the shell and tube reactor.
- After reaction, the gases are condensed using cooling water condenser. The
condensed isopropanol and acetone are sent for fractionation.
- The gases consisting of the remaining quantities of isopropanol and acetone are
absorbed into water using a water scrubber.
- The acetone + isopropanol obtained from the condenser and water + isopropanol
+acetone are sent to an acetone fractionator that separates acetone as the top
product and isopropanol + water as bottom product.
- The bottom product isopropanol + water from the acetone fractionators is sent to
a isopropanol column.
- This column produces water as the bottom product and isopropanol as the top
product.
- The water is cooled using a water condenser and sent to the water scrubber as
fresh water solvent.
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1.8.3 Description of the process of cumene
• Fresh cumene is mixed with hydrogenated unreacted cumene, cumene + alpha
methyl styrene (recycle streams).
• The pre-purification step involves converting unsaturates such as alpha methyl
styrene and others to saturates. This is done by using nickel catalyst at 100°C and
feeding hydrogen to the pre-purification reactor. The product from this unit then
mixes with the fresh cumene.
• The fresh cumene and processed cumene and alpha methyl styrene are fed to
the oxidation reactor. The oxidation reactor refers to a gas liquid reaction
between air (Oxygen) and the cumene.
• An emulsion of cumene is prepared in the oxidation reactor by adding alkali to
it.
• pH is maintained in the range of 8.5 – 10.5 to suit good emulsification
conditions.
• After reaction, vent gases are condensed and recycled back and the product is
sent to a cleavage unit.
• The cleavage unit consists of a stirrer and is fed with fresh and recycled
H2SO4 aqueous solution to enable the hydrolysis of cumene hydroperoxide.
• The product streams from the cleavage unit enter a settler (phase separator)
which upon gravity settling yields two streams namely the acid rich aqueous
stream and the phenol rich organic stream.
• The aqueous stream consists of the sulphuric acid and is sent back to the
cleavage unit as a recycle stream.
• The organic stream consists of cumene (unreacted), phenol (product), acetone
(side product), alpha methyl styrene (side product) and acetophenone (side
product).
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• The organic stream from the gravity settler unit then enters a scrubber fed with
water. In this operation, water extracts the remaining acids in the organic stream
and produces crude phenol stream. Water leaving the unit consists of acidified
wash water.
• The crude phenol then enters a distillation unit that separates acetone from the
other components.
• The bottom product from this distillation column enters a vacuum distillation
column that produces cumene as a top product.
• The bottom product from the distillation column enters another vacuum
distillation unit to produce alpha methyl styrene.
• The bottom product of this distillation column enters the final vacuum
distillation unit to produce phenol as top product and acetophenone as the
bottom product.
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