Kuwait University
Chemical Engineering Department
ChE491: PLANT DESIGN
Report(1): Literature Survey
Production of
Acetaldehyde
Written By:
Group Two:
Abdulhadi K. Alsaleh
Abdullah S. Alshemali
Abdulrhman S. Almutairi
Hamed M. Alazmi
Isam E. Elbadawi
Instructor:
Prof. Mohammed Fahim
Teaching Assistance:
Eng. Yusuf Ismail
Table of Contents
List of Figures: .............................................................................................................. II
List of Tables: .............................................................................................................. III
Introduction .................................................................................................................... 1
History............................................................................................................................ 1
World Production and Consumption ............................................................................. 1
Uses of Acetaldehyde .................................................................................................... 3
Feedstock & Product description and their physical and chemical properties .............. 4
Commercial processes for the production of acetaldehyde ........................................... 9
Comparison of presented process flow sheets ............................................................. 18
Conclusion ................................................................................................................... 20
Recommended flow sheet ............................................................................................ 20
References .................................................................................................................... 22
I
List of Figures:
Figure 1: Yearly Production and Consumption of Ethanol ........................................... 1
Figure 2: World Consumption of Acetaldehyde ............................................................ 2
Figure 3: Derivatives of Acetaldehyde .......................................................................... 3
Figure 4: Process Flow Diagram of Ethylene Oxidation. ............................................ 10
Figure 5: Process Flow Diagram for Oxidation of Ethanol. ........................................ 11
Figure 6: A PFD of Unit 100. ...................................................................................... 14
Figure 7: A PFD for Unit 200. ..................................................................................... 15
Figure 8 : Acetaldehyde from Vapor Phase Oxidation of Saturated Hydrocarbons. ... 17
Figure 9 : Acetaldehyde from Acetylene-Chisso Process............................................ 17
II
List of Tables:
Table 1: Yearly production and consumption of Ethanol .............................................. 2
Table 2: Physical and Chemical Properties for Ethanol ................................................ 4
Table 3: Physical and Chemical Properties for Acetaldehyde ....................................... 5
Table 4: Physical and Chemical Properties for Hydrogen Gas...................................... 6
Table 5: Physical and Chemical Properties for Ethyl Acetate ....................................... 6
Table 6: Physical and Chemical Properties for n-Butanol ............................................. 7
Table 7: Physical and Chemical Properties for Acetic Acid .......................................... 8
Table 8: Process flow rates per hour ............................................................................ 11
Table 9: Dimensions, material and building year of the different units. I stands for
inner and O for outer. ................................................................................................... 13
Table 10: The Gross Profit for Alternative A .............................................................. 18
Table 11: The Gross Profit for Alternative B .............................................................. 18
Table 12: The Gross Profit for Alternative C .............................................................. 18
Table13 : Comparison between the alternatives .......................................................... 19
III
Introduction
Acetaldehyde (ethanal) is a colorless liquid with a pungent, fruity odor. Acetaldehyde
is a volatile and flammable liquid that is miscible in water, alcohol, ether, benzene,
gasoline, and other common organic solvents. It is primarily used as a chemical
intermediate [1].
Commercial processes for the production of acetaldehyde include: the oxidation or
dehydrogenation of ethanol and the direct oxidation of ethylene.
History
Acetaldehyde was first prepared by Scheele in 1774, by the action of manganese
dioxide and sulfuric acid on ethanol. Liebig established the structure of acetaldehyde
in 1835 when he prepared a pure sample by oxidizing ethyl alcohol with chromic
acid. Liebig named the compound “aldehyde” from the Latin words translated as al
(cohol) dehyd (rogenated). Kutscherow observed the formation of acetaldehyde by the
addition of water to acetylene in 1881[1].
World Production and Consumption
a. Ethanol:
As we can see from Figure.1 below, both the production and consumption rates are
increasing yearly, but the production rates remain higher. Bigger increase of rates is
noticed since 2006 [16].
Figure 1: Yearly Production and Consumption of Ethanol
|Page1
Table 1:Yearly production and consumption of ethanol
year production consumption
2000
297.33
283.15
2001
318.30
261.85
2002
366.38
305.74
2003
459.69
359.80
2004
507.96
442.72
2005
584.28
499.18
2006
707.57
625.27
2007
919.11
804.62
2008 1,215.78
1,105.19
2009 1,310.33
1,271.09
b. Acetaldehyde:
Acetic acid consumption in manufacturing is decreasing. The reason behind it is that
the industry found a better and more efficient alternative which is carbonylation of
methanol process. As a result, demand of acetaldehyde is decreasing. Manufacture of
acetic acid from acetaldehyde is being discontinued around the world, except in Asia,
but further establishment of methanol carbonylation is going on. Further substitutions
of acetaldehyde-derived products are also happening. The chart below shows that
Asia is the dominant consumer of acetaldehyde.
Figure 2: World Consumption of Acetaldehyde
Expected growth in China consumption is 5% annually for the next five years. India is
expected to achieve 3% growth. The overall global market for acetaldehyde is
expected to get a growth of 2-3% annually between 2009-2014. By 2012, world
acetaldehyde market is expected to reach 1.26 million Tons according to New Report
by Global Industry Analysts [17].
|Page2
Uses of Acetaldehyde
About 95% of acetaldehyde is used as an intermediate for the production of other
organic chemicals. Acetic acid and acetic anhydride are the major derivatives of
acetaldehyde followed by n-butanol and 2-ethylhexanol. Also it can be used as an
antiseptic inhalant in nose troubles. See Figure.3 for other derivatives of
Acetaldehyde[19].
Acetic acid
acetaldehyde
ammonia
(a rubber
accelerator)
acetic
anhydride
metaldehyde
(solid fuel)
ethyl acetate
Acetaldehyde
paraldehyde
(hypnotic )
Chloral
dyes and
drugs
1,3butadiene
(used in
rubbers)
Figure 3: Derivatives of Acetaldehyde
|Page3
Feedstock & Product description and their physical and chemical
properties
Raw material
Ethanol
Ethanol (IUPAC name), also called ethyl alcohol, pure alcohol or drinking alcohol, is
a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest
recreational drugs. it is used in thermometers, as a solvent, and as a fuel. The
fermentation of sugar into ethanol is one of the earliest biotechnologies employed by
humanity. In modern times, ethanol intended for industrial use is also produced from
ethylene. Ethanol has widespread use as a solvent of substances intended for human
contact or consumption, including scents, flavorings, colorings, and medicines. In
chemistry, it is both an essential solvent and a feedstock for the synthesis of other
products. It has a long history as a fuel for heat and light, and more recently as a fuel
for internal combustion engines [3].
Table 2: Physical and Chemical Properties for Ethanol
Physical State
Appearance
Odor
pH
Vapor Pressure
Vapor Density
Evaporation Rate
Viscosity
Boiling Point
Freezing/Melting Point
Decomposition Temperature
Solubility
Specific Gravity/Density
Molecular Formula
Molecular Weight
Clear liquid
Colorless
Mild, rather pleasant, like wine or whisk
Not available.
59.3 mm Hg @ 20 oC
1.59
Not available
1.200 cP @ 20 oC
78 oC
-114.1 oC
Not available.
Miscible.
0.790 @ 20°C
C2H5OH
46.0414
|Page4
Final products
a. Acetaldehyde (main product)
Acetaldehyde (IUPAC name: Ethanal) is an organic chemical compound with the
formula (CH3CHO). It is one of the most important aldehydes, occurring widely in
nature and being produced on a large scale industrially. Acetaldehyde occurs naturally
in coffee, bread, and ripe fruit, and is produced by plants as part of their normal
metabolism. It is also produced by oxidation of ethanol and is popularly believed to
be a cause of hangovers from alcohol consumption through drinking spirits [5].
Table 3: Physical and Chemical Properties for Acetaldehyde
Physical state and appearance
Odor
Taste
Molecular Weight
Color
Boiling Point
Melting Point
Critical Temperature
Specific Gravity
Vapor Pressure
Vapor Density
Volatility
Odor Threshold
Solubility
Solubility in water
Liquid. (Fuming liquid.)
Fruity. Pungent. (Strong.)
Leafy green
44.05 g/mole
Colorless.
21°C
-123.5°C
188°C
0.78 (Water = 1)
101.3 kPa (@ 20°C)
1.52 (Air = 1)
Not available.
0.21 ppm
Easily soluble in cold
water, hot water. Soluble
in diethyl ether, acetone.
Miscible with benzene,
gasoline, solvent naphtha,
toluene, xylene,
turpentine.
1000 g/l @ 25 deg. C.
b. Hydrogen Gas (by-product)
Hydrogen gas is colorless, odorless and tasteless and is lighter than our air. Because
it is lighter than air it floats up higher than our atmosphere. This means that hydrogen
gas is not found naturally in our atmosphere, so in order to use it for our benefit we
must separate it from its other elements and collect it in vapor form. There are two
different methods that are used to help cause this separation of chemicals and allow
for this gas to form. They are steam and electrolysis but due to the damaging effects
on the environment caused by the steam method, electrolysis is more commonly used
[8]
.
|Page5
Table 4: Physical and Chemical Properties for Hydrogen Gas
Physical state
Appearance & odor
Odor threshold (PPM)
Vapor pressure
Vapor sp. gravity
(air=1)
Boiling point
Freezing point
Solubility in water (%)
Gas
Colorless, odorless gas
Odorless.
Gas@ 21°C
0.069 @ 21°C
-252.8°C (760 mmHg)
-259°C
Slight.
c. Ethyl Acetate (by-product)
Ethyl acetate (systematically, ethyl ethanoate, commonly abbreviated EtOAc or EA)
is the organic compound with the formula CH3COOCH2CH3. This colorless liquid has
a characteristic sweet smell (similar to pear drops) and is used in glues, nail polish
removers, and cigarettes. Ethyl acetate is the ester of ethanol and acetic acid; it is
manufactured on a large scale for use as a solvent [10].
Table 5: Physical and Chemical Properties for Ethyl Acetate
Physical State
Appearance
Odor
Vapor Pressure
Vapor Density
Evaporation Rate
Viscosity
Boiling Point
Freezing/Melting Point
Solubility
Specific Gravity/Density
Molecular Formula
Molecular Weight
Liquid
clear, colorless
sweet, fruity odor
73 mm Hg @ 20 oC
3.04 (Air=1)
6.2 (Butyl acetate=1)
0.44 cps @ 25 oC
77 oC
-83 oC
Slightly soluble.
0.9 (Water=1)
C4H8O2
88.11
d. n-Butanol (by-product)
n-Butanol or n-butyl alcohol or normal butanol is a primary alcohol with a 4-carbon
structure and the molecular formula C4H9OH. Its isomers include isobutanol, 2butanol, and tert-butanol. Butanol is one of the group of "fusel alcohols" (from the
German for "bad liquor"), which have more than two carbon atoms and have
significant solubility in water.n-Butanol occurs naturally as a minor product of the
fermentation of sugars and other carbohydrates, and is present in many foods and
|Page6
beverages. It is also a permitted artificial flavorant in the United States, used in butter,
cream, fruit, rum, whiskey, ice cream and ices, candy, baked goods and cordials. It is
also used in a wide range of consumer products. The largest use of n-butanol is as an
industrial intermediate, particularly for the manufacture of butyl acetate (itself an
artificial flavorant and industrial solvent). It is a petrochemical, manufactured from
propylene and usually used close to the point of manufacture [11].
Table 6: Physical and Chemical Properties for n-Butanol
Physical state and appearance
Odor
Molecular Weight
Color
Boiling Point
Melting Point
Specific Gravity
Vapor Pressure
Vapor Density
Odor Threshold
Solubility
Liquid.
Vinous. (Slight.)
74.12g/mole
Colorless.
117.7°C
-89.5°C
0.81(Water = 1)
0.6 kPa (@ 20°C)
2.55 (Air = 1)
1.2 ppm
Easily soluble in methanol, diethyl ether.
Partially soluble in cold water, hot water, noctanol.
e. Acetic Acid(by-product)
Acetic acid (IUPAC name Ethanoic acid) is an organic compound with the chemical
formula CH3CO2H (also written as CH3COOH). It is a colorless liquid that when
undiluted is also called glacial acetic acid. Acetic acid is the main component of
vinegar (apart from water), and has a distinctive sour taste and pungent smell. It is
mainly produced as a precursor to polyvinyl acetate and cellulose acetate. Although it
is classified as a weak acid, concentrated acetic acid is corrosive, and attacks the
skin.Acetic acid is one of the simplest carboxylic acids. It is an important chemical
reagent and industrial chemical, mainly used in the production of cellulose acetate
mainly for photographic film and polyvinyl acetate for wood glue, as well as synthetic
fibers and fabrics. In households, diluted acetic acid is often used in descaling agents.
In the food industry, acetic acid is used under the food additive code E260 as an
acidity regulator and as a condiment. As a food additive it is approved for usage in the
EU,US, and Australia and New Zealand [13].
|Page7
Table 7: Physical and Chemical Properties for Acetic Acid
Physical state and appearance
Odor
Taste
Molecular Weight
Color
pH (1% soln/water)
Boiling Point
Melting Point
Critical Temperature
Specific Gravity
Vapor Pressure
Vapor Density
Odor Threshold
Water/Oil Dist. Coeff.
Solubility
Liquid.
Pungent, vinegar-like, sour (Strong.)
Vinegar, sour (Strong.)
60.05 g/mole
Colorless. Clear (Light.)
2 [Acidic.]
118.1°C
16.6°C
321.67°C
1.049 (Water = 1)
1.5 kPa (@ 20°C)
2.07 (Air = 1)
0.48 ppm
The product is more soluble in water;
log(oil/water) = -0.2
Easily soluble in cold water, hot water.
Soluble in diethyl ether, acetone. Miscible
with Glycerol, alcohol, Benzene, Carbon
Tetrachloride. Practically insoluble in
Carbon Disulfide
|Page8
Commercial processes for the production of acetaldehyde
Alternative A
Acetaldehyde from Ethylene
a. Process Description:
The main reaction is:
C2H4 + 0.5 O2CH3CHO
First fresh oxygen and ethylene are fed to a vertical ceramic – lined reactor vessel
which contains a water solution of catalyst. The reactor operates at 120 – 130 C˚ and
3 atm. The evaporation of acetaldehyde and water from catalyst solution remove the
heat of reaction. The ethylene conversion per pass is approximately 75%. Second the
outlet from the reactor is fed to a gas-liquid separator to recover the catalyst. The
activated catalyst is recycled directly to the reactor and the deactivated catalyst is
regenerated by heating it then it recycled. The oxygen content of the recycle gas is
limited to maximum 9 mol% to stay safely below flammable range. After that the
vapor from separator is cooled and scrubbed with water to condense the outlet . This
operation is operating at low pressure and it need high scrub water volume. Most if
the vent gas is recycled to recover ethylene, but a gas purge is needed to remove
inserts from the system. The residue from the scrubber contains 8-10 wt%
acetaldehyde. Then this residue is fed to a light ends distillation column where
dissolved gasses, mehtylchloride and ethylchloride are removed. Finally the residue of
the distillation column is fed to Final distillation column which acetaldehyde taken as
a over-head product and crotonaldehyde is removed from middle of column. The
residue of final distillation mostly water with acetic acid and chlorinated acetaldehyde
which send to biological treatment plant (See Figure.4).
|Page9
Figure 4: Process Flow Diagram of Ethylene Oxidation.
b. Extra information:
For every 1000 Ib Acetaldehyde produced 670 Ib of Ethylene is consumed also 25
KWh electricity and 1200 Ib steam needed for utilities.
The catalyst used in this process is Palladium but it will be used in water solution
which contains copper salts and solutions mainly contain CuCl-2[19].
Alternative B
Oxidation of ethanol
a. Process Description:
This process is very similar to the (silver process) that is used to produce
formaldehyde, the big difference is that for acetaldehyde two distillation columns are
required while for formaldehyde only one is required. Since the process is oxidation,
air is required. Ethanol is first heated then mixed with air in a saturator. The saturated
stream will contain ethanol saturated in air. After that the stream is overheated in
order for it to be able to react later in the reactor. After that comes the heart of this
| P a g e 10
process, the reactor; the ethanol-saturated stream enters the reaction and undergoes
two main reactions and many other reactions that produce some by-products. The
catalyst used is silver. The product stream will be very hot; therefore, the heat of this
stream can be used to produce steam from water using a heat exchanger. Further
cooling is required to prepare the stream to enter the absorber, should be maintained
at 2 ˚C. The bottom stream from the absorber is sent to a distillation column to
separate acetaldehyde. The bottom of this distillation will contain ethanol, so another
column is used to separate this ethanol [2].
Figure 5: Process Flow Diagram for Oxidation of Ethanol.
Where a) Compressor; b) Saturator; c) Reactor; d) Absorption column; e) Mixing condenser; f)
Acetaldehyde distillation column; g) Ethanol distillation column.
b. Typical Compositions and Flow Rates:
Table 8: Process flow rates per hour
Ethanol
Electricity
Steam
Cooling
water
Waste water
Acetic acid
Exhaust
gases
Heat value
Fresh water
2500
1254
3071
114.7
kg/h
kWh
kg/h
m3/h
2.97
60
2485
m3/h
kg/h
kg/h
5136
2.0
MJ/h
m3/h
| P a g e 11
Yearly production: 16000 tons/year.
Overall ethanol to acetaldehyde yield: 93%
Air needed: 3000 kg/h
Ethanol needed: 2500 kg/h
Water needed: 2000 kg/h
Exhaust gases: 2485 kg/h
Acetaldehyde produced: 2122 kg/h
Acid water produced: 2892 kg/hr
c. Reactions Involved:
Desired reactions:
C2H5OH + ½ O2 → CH3CHO + H2O
C2H5OH → CH3CHO + H2
Undesired reactions:
C2H5OH + O2 → CH3COOH + H2O
C2H5OH + ½ O2 → CH4 + CO + H2O
C2H5OH + 2 O2 → 2 CO2 + 3 H2O
d. Thermodynamics & Kinetics of Reactions:
The overall reaction is exothermic and the temperature in the reactor is 550 °C, this is
why cooling is required before the absorption process.
e. Catalysts Used:
Silver catalyst is used for this process.
| P a g e 12
f. Types of Equipments:
Table 9: Dimensions, material and building year of the different units. I stands for inner and O for outer.
Bruchhausen
9.8
Mixing
condenser
Gent
9.2
Distillation
column
Bruchhausen
11.2
I/O = 0.99/1.0
2.0
I/O = 1.49/1.5
Unit
Saturator
Reactor
Abs column
From
Height (m)
Bruchhausen
4.9
Diameter (m)
I/O = 0.99/1.0
Material
1.4541
Building year
1989
Gent
8.847
I/O = 1.24
/1.25
1.4571 and
316
Assumed
1970
-
Column with
random
packing
-
Al 99.5
1960
Column with
random
packing
304 L and
316
Assumed
1970
Column with
random
packing
1.4571
1960
60 bubble cap
trays
Alternative C
Dehydrogenation of ethanol
a. Process Description:
Unit 100
A PFD of Unit 100 is shown in Figure.6 Ethanol, an 85-wt.% solution in water,
Stream 1, is combined with 85-wt.% ethanol recycle stream, Stream 23, from Unit
200. The resultant stream, Stream 2, is then pumped to 100 psia and heated to 626°F
in E-101 and E-102 before being fed to R-101, an isothermal, catalytic, packed-bed
reactor, where the ethanol is dehydrogenated to form acetaldehyde. The reactor
effluent is then cooled in E-103 and E-104. The resultant two-phase stream, Stream 8,
is then separated in V- 101. The vapor, Stream 9, is sent to T-101 where it is
contacted with water, which absorbs the acetaldehyde and ethanol from the vapor
stream. The resulting vapor effluent, Stream 11, is then sent for further processing and
recovery of valuable hydrogen. Alternatively, this stream could be used as fuel.
Stream 12, the liquid, is combined with Stream 14, the liquid effluent from V-101,
and sent to Unit 200.
| P a g e 13
Figure 6: A PFD of Unit 100.
Unit 200
A PFD for Unit 200 is shown in Figure.6. Stream 15 enters T-201 where the crude
acetaldehyde, Stream 16, exits as the distillate. This crude acetaldehyde is then sent to
T-203 where the acetaldehyde is purified to 99.9-wt.%, Stream 17. The bottom,
Stream 18, is sent to waste treatment. The bottom from T-201, Stream 19, is sent to T202 to begin the purification process of ethanol. In T-202, ethyl acetate and some
water is removed from Stream 19 and exits as the distillate, Stream 20, which is then
sent to waste treatment. The bottom, Stream 21, is sent to T-204 where ethanol is
separated from butanol, ethyl acetate, and most of the water. These impurities exit in
Stream 22 and are sent to waste treatment. The distillate consists of an 85-wt%
solution of ethanol, which is then recycled back to Unit 100 to be used in the feed.
Waste streams, Streams 18, 20, and 22, all contain small quantities of valuable
chemicals. Methods for their separation and purification should be investigated [18].
| P a g e 14
Figure 7: A PFD for Unit 200.
b. Reactions occur during the dehydrogenation of ethanol:
Main reaction:
CH3CH2OH → CH3CHO + H2
Side reactions:
2CH3CH2OH → CH3COOC2H5 + 2H2
2CH3CH2OH → CH3(CH2)3OH + H2O
CH3CH2OH + H2O → CH3COOH + 2H2
These side reactions we can decrease it by choosing the right catalyst which will lead
to complete the main reaction as possible of its activation, so the side reactions in this
case will decease which will help us in getting better design we look for it.
| P a g e 15
c.Equipment Summary
E-101 Reactor Preheater
E-102 Reactor Preheater
E-103 Heat Exchanger
E-104 Heat Exchanger
E-105 Heat Exchanger
E-201 Condenser
E-202Reboiler
E-203 Condenser
E-204 Reboiler
E-205 Condenser
E-206 Reboiler
E-207 Condenser
E-208 Reboiler
H-101 Fired Heater
P-101A/B Feed Pump
P-102A/B Dowtherm A Pump
P-201A/B Reflux Pump
P-202A/B Reflux Pump
P-203A/B Reflux Pump
P-204A/B Reflux Pump
T-101 Absorber
T-201 Distillation Column
T-202 Distillation Column
T-203 Distillation Column
T-204 Distillation Column
V-101 Flash Vessel
V-201 Reflux Vessel
V-202 Reflux Vessel
V-203 Reflux Vessel
V-204 Reflux Vessel
| P a g e 16
Another Alternative
Acetaldehyde can be produced by oxidation of butane propane, or mixtures. The
process is no longer important as an acetaldehyde process because it is not selective
and required the recovery of a wide range of chemical including formaldehyde,
methanol, acetone, glycols, and many other compounds. See figure 8 for the process
[19]
.
Figure 8 : Acetaldehyde from Vapor Phase Oxidation of Saturated Hydrocarbons.
Also acetaldehyde can be produced by hydration of acetylene. The acetylene process
uses sulfuric acid as a reaction component so corrosion resistance equipment must be
used. In addition this process uses mercury which is an expensive, toxic and difficult
to handle. Furthermore, acetylene is highly reactive gas must be properly handled.
Finally; the major problem of manufacture acetaldehyde from acetylene is the high
price of acetylene .See figure 9 for the process [19].
Figure 9 : Acetaldehyde from Acetylene-Chisso Process.
| P a g e 17
Comparison of presented process flow sheets
1. Alternative A: Oxidation of Ethylene
Table 10: The Gross Profit for Alternative A
Alternative A
Mole
M.wt
Ib
Ib/Ib of CH3CHO
$/Ib
Gross Profit =
C2H4
1
28.05
28.05
0.637
0.675
0.025
O2
CH3CHO
0.5
1
32
44
16
44
0.363
1
0
0.455
$/Ib of CH3CHO
2. Alternative B: Oxidation and Dehydrogenation of Ethanol
Table 11: The Gross Profit for Alternative B
Alternative B
Mole
M.wt
Ib
Ib/Ib of CH3CHO
$/Ib
Gross Profit =
C2H5OH
2
46
92
1.045
0.372
O2
0.5
32
16
0.181
0
0.0914
CH3CHO
H2O
H2
2
1
1
44
18
2
88
18
2
1
0.204
0.022
0.455
0
1.12
$/Ib of CH3CHO
3. Alternative C: Dehydrogenation of Ethanol
Table 12: The Gross Profit for Alternative C
Alternative C
Mole
M.wt
Ib
Ib/Ib of CH3CHO
$/Ib
Gross Profit =
C2H5OH
1
46
46
1.045
0.3721
0.116
CH3CHO
H2
1
1
44
2
44
2
1
0.045
0.455
1.12
$/Ib of CH3CHO
| P a g e 18
Table13: Comparison between the alternatives
Alternative A:
This alternative has the lowest gross profit among the three alternatives, also
the lowest number of main equipment. The catalyst can be reactivated in the same
plant and the raw material is available locally. Highly precise control methods should
be used to maintain the oxygen content of the recycle gas below 9 mol%.
Alternative B:
Our second alternative has the highest number of equipment. The catalyst used
is expensive, and the required amount is 70 kg, but it can last up to one year. Ethanol
is not produced locally so it has to be imported which will make the price of ethanol
higher than ethylene. Also it has a high gross profile while comparing it with
Alternative A. The only downside of this alternative is the temperature of the absorber
which should be kept at 2 ˚C.
Alternative C:
This last alternative has the highest gross profit. Similarly to Alternative B, the
raw material should be imported. Due to high pressure conditions in the whole plant,
careful control methods should be used to guarantee that the safety parameters are
present; because high pressure is a dangerous parameter to deal with.
| P a g e 19
Conclusion
Clearly, Alternative A is eliminated due to the low gross profit compared to the other
two. Alternative C and Alternative B have the same raw material, and both of them
need special equipment to deal with the high pressure in Alternative C and the low
temperature in Alternative B. But Alternative C has the highest gross profit so
Alternative C is chosen.
Recommended flow sheet
Alternative C is recommended among the three due to the comparison and
conclusion mentioned above.
Figure.6: Process Flow Diagram for Alternative C
| P a g e 20
Figure.7: Process Flow Diagram for Alternative C.
| P a g e 21
References
A) Web Sites :
1. Scribd : http://www.scribd.com/doc/78883816/Project-on-Deepak
2. Chemeng: http://www.chemeng.lth.se/exjobb/E572.pdf
3. Wikipedia :http://en.wikipedia.org/wiki/Ethanol
4. nafaa :http://www.nafaa.org/ethanol.pdf
5. Wikipedia :http://en.wikipedia.org/wiki/Acetaldehyde
6. Sciencelab :http://www.sciencelab.com/msds.php?msdsId=9922768
7. Uigi: http://www.uigi.com/MSDS_gaseous_H2.html
8. hydrogen-gas : http://www.hydrogen-gas.co.uk/
9. fishersci :https://fscimage.fishersci.com/msds/08750.htm
10. Wikipedia:http://en.wikipedia.org/wiki/Ethyl_acetate
11. Wikipedia:http://en.wikipedia.org/wiki/N-Butanol
12. Sciencelab: http://www.sciencelab.com/msds.php?msdsId=9927115
13. Wikipedia:http://en.wikipedia.org/wiki/Acetic_acid
14. Sciencelab:http://www.sciencelab.com/msds.php?msdsId=9922769
15. Icis: http://www.icis.com/StaticPages/a-e.htm
16. Prweb: http://www.prweb.com/releases/acetaldehyde/acetic_acid/prweb1553564.htm
17. Petronet:
18. WVU:
http://www.petronet.ir/index.php?module=content&func=viewpage&pageid=701&newlang=eng
http://www.che.cemr.wvu.edu/publications/projects/large_proj/Acetaldehyde.PDF
B) Books:
19. John J.Mckett, Encyclopedia of Chemical Processing and Design ,Volume
1, Pages (114-163).
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