interim -2010final
TRANSCRIPT
CAB 4013
PLA�T DESIG� I
July 2010 Semester
I�TERIM REPORT :
POLYETHYLE�E TEREPHTHALATE (PET) PRODUCTIO�
BASED O� ESTERIFICATIO� PROCESS TECH�OLOGY
GROUP 28
MUHAMMAD AIMEN BIN ISA 10284
MUNIRAH BINTI SAMSUDDIN 9813
NIK ASMADI BIN AZNAN 9603
AHMAD NIZAR BIN YUNUS 10216
NUR FATHIAH BINTI JASMARI 10233
CHEMICAL ENGINEERING PROGRAMME
UNIVERSITI TEKNOLOGI PETRONAS
Bandar Sri Iskandar, 31750 Tronoh, Perak Darul Ridzuan
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CERTIFICATIO� OF APPROVAL
CAB 4013
PLA�T DESIG� I
July 2010 Semester
I�TERIM REPORT :
POLYETHYLE�E TEREPHTHALATE (PET) PRODUCTIO�
BASED O� ESTERIFICATIO� PROCESS TECH�OLOGY
GROUP 28
MUHAMMAD AIMEN BIN ISA 10284
MUNIRAH BINTI SAMSUDDIN 9813
NIK ASMADI BIN AZNAN 9603
AHMAD NIZAR BIN YUNUS 10216
NUR FATHIAH BINTI JASMARI 10233
APPROVED BY,
( IR. DR. ABD HALIM SHAH MAULUD )
CHEMICAL ENGINEERING PROGRAMME
UNIVERSITI TEKNOLOGI PETRONAS
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EXECUTIVE SUMMARY
Polyethylene Terephtalate is a thermoplastic polymer resin of the polyester family and
most often used to make synthetic fibers, containers for food and beverages, pharmaceuticals,
make-up and other thermoforming applications, where engineering resins often come out in
combination with glass fiber. Polyethylene terephthalate is frequently shortened to PET or
PETE. In order to produce PET, there are two major processes, called esterification and
transesterification, where esterfication used ethylene glycol (EG) and terephthalic acid (TPA)
as its raw material while transesterification used EG and dimethylterephthalate (DMT).
Regarding these two process, both will be further explain in the next chapter as well as why
esterification process is being choose in this project.
Technically speaking, PET is a linear thermoplastic resin that has several advantages,
especially when it’s being used for packaging. PET does not break easily and edibles stored
since it acts as a good barrier to elements outside of the container. The main objective of this
project is to investigate the feasibility of setting up a polyethylene terephthalate (PET)
producing plant based on the selected process technology.
Throughout this project, Chapter 1 will mainly emphasize on the project background,
problem statement as well as scope of work, while the Chapter 2 gives details of the project
background, market survey, properties of chemicals used, site feasibility study and feedstock
supply. The location chosen for the plant is Kerteh because of the availability of raw material
utilities and transportation. On the other hand, Chapter 3 discusses the preliminary hazard
analysis which includes identification of material and chemical hazard, safety aspects in order
to reduce potential accidents and also local safety regulations.
Then analysis on the conceptual process design was done in Chapter 4. It is important
to understand the basic principle of the whole process ; such as what reaction is taken place,
chemical reaction involved and types of reactor that we should used. In this chapter, the plant
is to be operated in continuous mode and the type of reactor used is the conversion reactor.
The separation units required for the process route is including distillation column for the
purification of ethylene glycol (EG) or act a main medium to separate water during reaction.
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In achieving better conversion, unreacted EG is recycled to the main stream. Overall, the
whole process of producing PET was done by using iCON simulation result.
Chapter 5 mainly describes the process flow and process flowsheet as well as manual
calculation on iCON simulation result of material balance. Heat integration calculation is also
mentioned by using pinch technology, in order to maximized energy used. Meanwhile, in
Chapter 6, the description about the process is determine by types of reactor used.
Throughout the project, estimate production rate of the plant is 30,449 ± 1.72 kg/year,
which is equivalent to 30.449 ± 0.00172 tonnes per annum with high purity of PET produced,
98 ± 0.4%. Thus, the proposed plant design will be justified based on the economic potential
of the process, by comparing the price of PET and price of raw materials needed (TPA and
EG). Hence, overall process description on this project will be further explained in each
chapter that has been mentioned earlier.
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ACK�OWLEDGEME�T
Alhamdulillah, thanks to Allah for giving us opportunity to complete this Plant
Design 1 course for this semester after have been struggling with all the problems and
challenges in completing this design project for the past several months.
There were about fourteen (14) weeks have been given to us in completing the design
project in Plant Design Project 1 (CAB4013) course under the supervision of our keen
supervisor, Ir Dr Abd Halim. We as the member of this group would like to pass our highest
gratitude to Ir Dr Abd Halim for all his guidance and continuous supports throughout the
semester. He has been a very supportive supervisor and willing to share his knowledge, in
order ensure that we could learn and understand every single thing in this project. Our
gratitude is also extended to PDP 1 coordinator, Dr. Rajashekhar Pendyala and Dr. Ridza for
their efforts in arranging the iCon seminar and planning the course structures so that we could
complete our project smoothly throughout this whole semester.
Last but not least our appreciation is to our beloved group mates, course mates and
also friends, thanks for all the supports and motivations that help us to complete this project
with a successful ended. Not to forget to those who directly or indirectly involved in giving
us the opportunity to learn and work as a team while designing our first plant project.
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TABLE OF CO�TE�TS
EXECUTIVE SUMMARY ..................................................................................................... 3
ACK�OWLEDGEME�T ....................................................................................................... 5
ALHAMDULILLAH, THA�KS TO ALLAH FOR GIVI�G US OPPORTU�ITY TO
COMPLETE THIS PLA�T DESIG� 1 COURSE FOR THIS SEMESTER AFTER
HAVE BEE� STRUGGLI�G WITH ALL THE PROBLEMS A�D CHALLE�GES I�
COMPLETI�G THIS DESIG� PROJECT FOR THE PAST SEVERAL MO�THS. ... 5
LIST OF FIGURES ................................................................................................................. 9
CHAPTER 1 : I�TRODUCTIO� ........................................................................................ 11
1.1 BACKGROU�D OF DESIG� PROJECT .................................................................................. 11
1.2 PROBLEM STATEME�T ........................................................................................................ 11
FIGURE 1 : GLOBAL PET DEMA�D ............................................................................... 12
1.3 OBJECTIVE ........................................................................................................................... 13
1.4 SCOPE OF WORK .................................................................................................................. 14
CHAPTER 2 : LITERATURE REVIEW ........................................................................... 15
2.1 BACKGROU�D OF DESIG� PROJECT .................................................................................. 15
2.1.1 Overview of product, feedstock and byproducts ........................................................... 15
2.1.2 Process Primary Routes to PET Production ................................................................. 19
2.1.3 Process Alternative Routes ........................................................................................... 20
2.1.4 History, Applications and Usage .................................................................................. 22
2.2 PRODUCT MARKET SURVEY ............................................................................................... 24
2.2.1 Resources and raw Materials ....................................................................................... 24
2.2.2 Global Market Outlook ................................................................................................. 27
2.2.3 Asian Market Outlook ................................................................................................... 28
2.2.4 Overall Market Outlook ................................................................................................ 30
2.2.5 Overall Production Estimation ..................................................................................... 31
SITE FEASIBILITY STUDY ................................................................................................................ 32
2.2.6 Introduction ................................................................................................................... 32
2.2.7 Selection Criteria .......................................................................................................... 32
2.2.8 Contributing Factors in Site Selection .......................................................................... 33
2.2.9 Summary Of Characteristic at Each Location .............................................................. 35
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2.2.10 Concluding Remark ............................................................................................... 41
2.3 PHYSICAL A�D CHEMICAL PROPERTIES ............................................................................ 43
2.3.1 Polyethylene Terephthalate (PET) ................................................................................ 43
2.3.2 Ethylene Glycol (EG) .................................................................................................... 43
2.3.3 Diethyl Glycol (DEG) ................................................................................................... 44
2.3.4 bis-hydroxyethyl terephthalate (BHET) ........................................................................ 44
2.3.5 Terephthalic Acid (TPA) ............................................................................................... 45
2.3.6 Water ............................................................................................................................. 45
2.4 FEEDSTOCK SUPPLY ............................................................................................................ 46
2.4.1 Supplier Profile ............................................................................................................. 46
CHAPTER 3 : PRELEMI�ARY HAZARD A�ALYSIS .................................................. 48
3.1 SAFETY ISSUES A�D PRELIMI�ARY HAZARD A�ALYSIS ................................................... 48
3.2 IDE�TIFICATIO� OF MATERIAL A�D CHEMICAL HAZARD .............................................. 48
3.3 EMERGE�CY SITUATIO� PROCEDURE ............................................................................... 58
3.4 LOCAL SAFETY REGULATIO�S ........................................................................................... 59
CHAPTER 4: CO�CEPTUAL DESIG� A�ALYSIS ....................................................... 62
4.1 PRELIMINARY REACTOR OPTIMIZATION .................................................................................... 62
4.1.1 Reactions Involved ......................................................................................................... 62
4.1.2 Esterification Reaction .................................................................................................. 62
4.1.3 Polymerization Reactions .............................................................................................. 64
4.2 PROCESS SCREE�I�G .......................................................................................................... 66
4.2.1 Heuristic Approach for Separation System Synthesis.................................................... 66
4.2.2 Sequencing of Separators .............................................................................................. 66
4.2.3 Operating Conditions for Separators ............................................................................ 68
4.3 ECO�OMIC POTE�TIAL (EP) .............................................................................................. 69
4.3.1 Economy Analysis .......................................................................................................... 69
4.3.2 Total Capital Investment ............................................................................................... 69
4.3.3 Fixed Capital Investment .............................................................................................. 70
4.3.4 Working Capital Investment .......................................................................................... 72
4.3.5 Start Up Cost ................................................................................................................. 72
4.3.6 Total Capital Investment ............................................................................................... 73
4.3.7 Utilities .......................................................................................................................... 73
4.4 MASS BALANCE BY MANUAL CALCULATION & ICON SIMULATION ......................................... 77
4.4.1 Block Diagram for Production of PET Process ............................................................ 82
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CHAPTER 5 : HEAT I�TEGRATIO� .............................................................................. 83
5.1 PI�CH A�ALYSIS .................................................................................................................. 83
5.5.1 Pre-design Target for Utility Consumption .................................................................. 83
5.2 DIFFERE�CE I� HEAT EXCHA�GER DUTY REQUIREME�T BEFORE A�D AFTER HEAT
I�TEGRATIO� (HI) .......................................................................................................................... 90
CHAPTER 6 : PROCESS DESCRIPTIO� ........................................................................ 91
6.1 PROCESS DESCRIPTION ............................................................................................................... 91
6.2 FEED RAW MATERIAL ................................................................................................................ 92
6.3 REACTIONS INVOLVED................................................................................................................ 92
6.31 Esterification Process ..................................................................................................... 92
6.32 Separation Process ......................................................................................................... 93
6.33 Purging system ............................................................................................................... 95
6.34 Polycondensation Process .............................................................................................. 96
CHAPTER 7 : CO�CLUSIO�S .......................................................................................... 99
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LIST OF FIGURES
Figure 1 : Global PET Demand ............................................................................................... 12
Figure 2 : Usage of PET........................................................................................................... 24
Figure 3 : World Consumption of Ethylene Glycol ................................................................. 25
Figure 4 : Usage of Ethylene Glycol........................................................................................ 24
Figure 5 : World Consumption of TPA ................................................................................... 26
Figure 6 : TPA World Consumption In Year 2009.................................................................. 27
Figure 7 : Global PET Demand by Regions ............................................................................ 28
Figure 8 : World Consumption of PET Resins ........................................................................ 29
Figure 9: Tariff for High Voltage Industries............................................................................ 70
Figure 10 : Overall Esterifiction Reaction ............................................................................... 60
Figure 11 : Pre-Polycondensation Reaction ............................................................................. 61
Figure 12 : Final Polycondensation Reaction .......................................................................... 62
Figure 13 : Block Diagram of the Process ............................................................................... 80
Figure 14: Heat Balance By Manual Calculation .................................................................... 82
Figure 15 : Problem table Algorithm By manual Calculation ................................................. 83
Figure 16 : Composite Curve generated by using Aspen HX-Net 2006 software ................... 85
Figure 17 : Grand Composite Curve generated by using Aspen HX-Net 2006 software ........ 86
Figure 18 : Heat Exchanger Network ...................................................................................... 87
Figure 19 : Reaction Flow of PET Production......................................................................... 89
Figure 20 : Esterification Process ............................................................................................ 91
Figure 21 : Series of Esterification Reactor ............................................................................. 91
Figure 22 : Ethylene Glycol Recovery System ........................................................................ 92
Figure 23 : Purging Syatem ..................................................................................................... 93
Figure 24 : Series of Polycondensation Process ...................................................................... 95
Figure 25 : Reactions of Functional Group in PET Production Stage ..................................... 96
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LIST OF TABLES
Table 1 : Contributing Factors to Operability and Economy Aspects ..................................... 30
Table 2 : Summary Of Justification On Site Location ............................................................. 35
Table 3 : Weighted marks and explanation on the plant site location factors ......................... 38
Table 4 : Weight Matrix On Site Location .............................................................................. 39
Table 5 : PET Properties .......................................................................................................... 41
Table 6 : EG Properties ............................................................................................................ 41
Table 7 : DEG Properties ......................................................................................................... 42
Table 8 : BHET Properties ....................................................................................................... 42
Table 9 : TPA Properties.......................................................................................................... 43
Table 10 : Water Properties ..................................................................................................... 43
Table 11 : Equipment Required and Estimated cost for PET Plant ......................................... 67
Table 12 : Fixed Capital Investment for PET Production Plant .............................................. 68
Table 13 : Plant Utilities ......................................................................................................... 71
Table 14 : MSDS for Selected Chemical ................................................................................. 47
Table 15 : Safety Risk and Mitigation Measures ..................................................................... 54
Table 16 : Separators with types of mixtures and Operating Condition .................................. 65
Table 17: Data from iCon Simulation ...................................................................................... 81
Table 18 : Summary Of % Saving After Heat Integration ....................................................... 88
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CHAPTER 1 : I�TRODUCTIO�
1.1 Background of Design Project
Polyethylene Terephthalate (PET) has been widely used, especially when plastics
bottles or food container popped-out in our mind. Thus, the advantages of PET have been
explored to understand its importance in industries. In Malaysia, we do understand that there
is no PET production plant exists, but somehow, Malaysia does have several companies
whom buy PET from other countries and process PET into plastics or any other necessary
PET-based products. These companies act as a supplier to supply and process PET, before
they distribute them in the form of desired products. Referring to our title ‘PET Production
Based On Esterification Process’, there are two basic raw material involved, which consists
of Ethylene Glycol (EG) and Terephthalic Acid (TPA).
Consequently, depending on PET processing and thermal history, PET may exist both
as an amorphous (transparent) or as a semi-crystalline material. The semi-crystalline material
might appear transparent or opaque and white, depends on its crystal structure and particle
size. During esterification process, reaction between Ethylene Glycol (EG) and Terephthalic
Acid (TPA) will produce monomer bis-hydroxyethyl terephthalate (BHET) and water as
byproduct.
1.2 Problem Statement
Based on the increasing number of PET demand, a petrochemical plant of
Polyethylene Terephthalate (PET) has been discussed to be constructed in Malaysia. As being
mentioned earlier, PET production plant will considered esterification process as its produce
only water as its byproduct. Generally, the plant is expected to operate for 330 days in a year,
including maintenance work or plant shutdown. The interest rate for the project is estimated
to be 10% per year and the project life is about 20 years. Thus, the whole study about this
coming construction plant needs to be developed to cater its manufacture and economical
feasible production capacity.
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The majority of the world's PET production is for synthetic fibers (in excess of 60%)
with bottle production accounting for around 30% of global demand. In discussing textile
applications, PET is generally referred to as simply "polyester" while "PET" is used most
often to refer to packaging applications. PET consists of polymerized units of the monomer
ethylene terephthalate, with repeating C10H8O4 units. PET is commonly recycled, and has the
number "1" as its recycling symbol.
Referring to below diagram on the Global PET demand, it is expected that year 2020
will needed huge amount of PET, which is approximately reaching 27 Million Tons. As the
demand increase proportionally with time, huge PET production is also expected to increase
by the existing number of plant or manufacture. By also considering the usage of PET
whether in industries or non-industries, Malaysia is about to take one step ahead in planning
and setting up a new plant for its own benefits.
Figure 1 : Global PET Demand
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1.3 Objective
Plant Design Project (PDP) 1 has come out with its own objective, especially to
educate and develop simulation skills among students. The project of designing industrial
plant required knowledge, passion and attitude in solving design problems for typical process
exists in industrial plant. Hence, this project is given with its own purpose ;
• To complete the design of PET Production plant by conducting literature survey,
which includes its process routes, properties, uses, and market cost data.
• To identify chemical and physical properties for all raw materials, intermediate
products, final products and environmental and safety considerations.
• To study and select the best process route of producing PET for a selected design
project (chosen process - esterification).
• To perform energy balance calculations and apply related computer-aided design
engineering software (iCON) as a tool for the design.
• To make necessary decisions, judgments and assumptions in design problems.
• To execute the process design and mechanical design of the major process units by
doing research on equipment used.
• To perform economic evaluation including capital cost estimation and manufacturing
cost estimation.
• To understand the environmental and safety issues related to the plant, by discussing
potential chemical hazard in the process.
• To develop working skills in a team and understand the basic principles of plant
design as well as reaction involved
• To generate cost effective process and maintain operation safety
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1.4 Scope of Work
There are several guidelines or scope of work that has been highlighted in this design
project, which mainly includes ;
• Conduct literature review survey about the product including its properties, usage,
cost, process involved, chemical and physical properties of raw materials, final
products, environmental considerations and safety considerations
• A clear complete Process Flow Diagram (PFD) of optimized process including all the
equipment.
• Provide stream flow table including all the stream variables e.g. temperature,
pressure, total flow rate and component flow rate.
• Identify and select the best process route for this design project
• Develop and performed complete material and energy balance calculations for
selected process
• Use related computer-aided design/engineering software (e.g. iCON, HYSYS, Visio
and Microsoft Excel) as the main tools for the design
• Make necessary decisions, judgments and assumptions based on plant design
knowledge, especially to solve design problems
• Perform economic evaluation including economic potential and initial cost estimation
• Consider environmental and safety issues which related to the plant
• Prepare preliminary and interim report as per standard format and do a presentation
on the design plant
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CHAPTER 2 : LITERATURE REVIEW
2.1 Background of Design Project
2.1.1 Overview of product, feedstock and byproducts
Product : Polyethylene Terephthalate (PET)
Polyethylene Terephthalate (PET)
In the 1950s, Polyethylene terephthalate (PET) came into prominence as a textile
material. PET is supplied by resin manufacturers in the form of small pellets, which each of
them are approximately 0.05 gram in size. Its strength, temperature tolerance and wear-
resistance made it an ideal replacement for or addition to natural fibers such as silk, cotton
and wool. PET is also a linear thermoplastic, which have long-chain molecule and consists of
repeating units, with white but bluish characteristics of resin. PET is made from terephthalic
acid and ethylene glycol through poly-condensation.
PET is also belongs to semi-crystalline polymer group and when heated above 72°C,
PET will change from a rigid glass-like state into a rubbery elastic form. In this condition,
polymer molecular chains can be stretched and aligned in either one direction to form fibres,
or in two directions to form films and bottles. Consequently, if the material melt is cooled
quickly, the chains will be frozen, with their orientation remaining intact in the stretched
state. Crystallization of PET in this condition makes the material starts to become opaque,
more rigid and less flexible. However, nowadays, many modifications are introduced to
develop specific properties for the various packaging applications to suit particular
manufacturing equipment. Special grades are offered with the required properties for the
different applications.
In industries, the best thing about PET is that it can be recycled to make many new
products, including fiber for polyester carpet; fabric for T-shirts, long underwear, athletic
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shoes, luggage, upholstery and sweaters; fiberfill for sleeping bags and winter coats; and new
PET containers for both food and non-food products.
By recycling, there are lots of advantages has been proved, such as ;
• Recycling a ton of PET containers saves 7.4 cubic yards of landfill space.
• According to the EPA, recycling a pound of PET saves approximately 12,000
BTU's.
• The average household generated 42 pounds of PET plastic bottles in the year
2005.
• Custom bottles (which are bottles used for products other than carbonated soft
drinks) represent 62% of all PET bottles available for recycling.
Feedstock : Terephthalic Acid (TPA) and Ethylene Glycol (EG)
Terephthalic Acid (TPA)
Terephthalic acid is an organic compound with formula C6H4(COOH)2. The
abbreviation used for this acid is TPA. The common properties for TPA are colorless solid,
and it is being used in the application of polyester PET, especially for clothing and plastic
bottles. In industries, several billion kilograms are produced annually to cater the needs of
TPA in many sectors. TPA also considered as one of the three isomeric phthalic acids. In this
project, TPA used is assume to be 100% purified. Another characteristic for terephthalic acid
is including poorly soluble in water and alcohols, and most of the crude terephthalic acid was
converted to dimethyl ester for purification. PTA also sublimes when heated (since it is
already mentioned that PTA is in a solid condition).
Virtually the entire world's supply of terephthalic acid is consumed as precursors to
polyethylene terephthalate (PET), as TPA is plays very important role for PET production
(raw material). With lots of application of PTA, by 2006, global purified terephthalic acid
(PTA) demand had exceeded 30 million tonnes. While in the research laboratory, terephthalic
acid has been popularized as a component for the synthesis of metal-organic frameworks.
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Ethylene Glycol (EG)
Ethylene glycol is an organic compound widely used as an automotive antifreeze and
also the main precursor to polymers. Ethylene glycol falls under alcohol group with formula
C2H6O2. The short form for ethylene glycol is EG, where in its pure form, it is odorless,
colorless, syrupy and sweet-tasting liquid. Ethylene glycol is also known to be toxic, and
ingestion can result in death.
Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene
oxide. In this reaction, the major byproducts are ethylene glycol oligomers, diethylene glycol,
triethylene glycol, and tetraethylene glycol. In industries, about 6.7 billion kilograms of EG
are produced annually. Another application of EG are includes ; medium for coolant and heat
transfer, hydration inhibition to remove water and inorganic salts, and in niche application.
Byproducts : Diethyl glycol (DEG), bis-hydroxyethyl terephthalate (BHET) and Water
Diethyl glycol (DEG)
Diethyl glycol (DEG) is a class of organic chemicals groups that contribute to high
water solubility and reactivity with many organic compounds, usually linear and aliphatic
carbon chain. The general formula for DEG is O(CH2CH2OH)2. Ethylene glycol is the
simplest member of the glycol family. Mono-, di- and triethylene glycols are the first three
members of a homologous series of dihydroxy alcohols. The basic characteristic of EG is a
colorless, odorless, involatile and hygroscopic liquid with a sweet taste. It is somewhat
viscous liquid, which miscible with water. In plastic industries, EG has become increasingly
important for the manufacture of polyester fibers and resins, including polyethylene
terephthalate, which is used to make plastic bottles for soft drinks (PET bottles). Ethylene
glycol is by far the largest volume of the glycol products in a variety of applications including
anti-freezing additive, intermediate polymer, solvent or plasticizer for plastic, dehydrating
and textile conditioning.
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bis-hydroxyethyl terephthalate (BHET)
Throughout this project, bis-hydroxyethyl terephthalate (BHET) is known as
monomer in the production of PET. BHET is then polymerized up to about 30 in
polymerization process. One of the characteristic found in BHET is that it is obtained as an
amorphous to very finely crystalline mass and difficult to separate. This BHET can undergo
polycondensation process and to be removed during PET production process without any
further additives. However, polycondensation of BHET with the addition of a corresponding
molar amount of terephthalic acid makes it possible to utilize this ethylene glycol to produce
huge amount of PET.
Water (H2O)
In this project of PET production plant, we have decided to choose esterification
process as the main route. Thus, the main byproduct produced is water. Water is widely
known as a liquid at ambient conditions, but it often co-exists on Earth with its solid state,
ice, and gaseous state, water vapor or steam. Water is a tasteless, odorless liquid at standard
temperature and pressure. The color of water and ice is, intrinsically, a very slight blue hue,
although water appears colorless in small quantities. Water is also transparent, where sunlight
can be seen through water.
Water is a good solvent and is often referred to as the universal solvent. Substances
that dissolve in water, for example ; salts, sugars, acids, alkalis, and some gases – especially
oxygen, carbon dioxide (carbonation) are known as hydrophilic (water-loving) substances,
while those that do not mix well with water such as fats and oils, are known as hydrophobic
(water-fearing) substances. All the major components in cells (proteins, DNA and
polysaccharides) are also dissolved in water. Pure water has a low electrical conductivity, but
this increases significantly with the dissolution of a small amount of ionic material.
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2.1.2 Process Primary Routes to PET Production
Production of Polyethylene Terephthalate (PET) has two major processes, which are
esterification and transesterification. In this project, we have decided to choose esterification
process instead of transesterification process. In this context, overview of feedstock, product
and byproducts will be highlighted, while details about transesterification process will be
discussed later in the process alternative routes, where we put this process as our second
option. By referring to esterification basic definition, the process is the general name for a
chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as
the reaction product. During the process, main chemicals involved are ethylene glycol (EG)
and terephthalic acid (TPA) with water as the byproducts.
The primary reaction for esterification process is ;
During the process, ethylene glycol (EG) and terephthalate acid (TPA) react with each other
at 190°C in the presence of an inert gas, such as nitrogen, yielding bis-hydroxyethyl
terephthalate (BHET) :
bis-hydroxyethyl terephthalate (BHET)
The terephthalic acid and ethylene glycol are mixed to form a paste, allowing more
accurate control of the feed rates to the esterification vessels. The number of reactors and
their operating conditions depends on the type of PET being produced. In this case, ratio of
EG and TPA is 1:1.2 respectively (by considering recycle stream). Typically, in this process,
there are two stage of esterification processes, two stage of polycondensation process and one
distillation column involved mainly for water removing. Esterification process 1 converts
95% of reaction involved while the second process converts 98% of the first reaction. As for
polymerization process, both processes are assumed to be 100% conversion.
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Consequently, TPA and EG process generally involves a system similar to that of the
DMT process. The major difference is the lack of a methanol recovery step and it involved
only one catalysts ; Antimony Trioxide.
2.1.3 Process Alternative Routes
One of the alternative PET process routes is known as transesterification.
Transesterification process used dimethylterephthalate (DMT) and ethylene glycol (EG). In
this process, EG is drawn from raw material storage and fed to a mix tank, where catalysts
and additives are mixed along with DMT, to the esterifiers. This reaction produces the
intermediate BHET monomer and methanol as the byproduct. During transesterification,
methanol vapor must be removed from the esterifiers to shift the conversion to produce more
BHET.
Chemical reaction involved during transesterification ;
The BHET monomer, with other esterifier products, is fed to a polymerization reactor
where the temperature is increased and the pressure is decreased. At these operating
conditions, residual methanol and ethylene glycol are vaporized, and the reaction that
produces PET resin starts, where the final temperature and pressure depend on whether low
or high viscosity PET is being produced. For high-viscosity PET, more process vessels are
used to achieve higher temperatures and lower pressures, compared to low-viscosity.
Throughout this process, ethylene glycol can be recovered by using recovery system,
which is usually a distillation composed of a low boiler column, a refining column, and
associated equipment. Product from the polymerization reactor (referred to as the polymer
melt) may be sent directly to fiber spinning and drawing operations. Alternatively, the
polymer melt may be chipped or pelletized, put into product analysis bins, and then sent to
product storage before being loaded into hoppers for shipment to the customer.
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Below is a simple comparison between the two existence process, esterification and
transesterification ;
Based on above table, esterification process involved EG and TPA as its raw material
and produced water as the byproducts. Since the technology was introduced in year 1963, it is
newer process than transesterification process. Water can be recycled to other types of usage
such as for reducing heat, thus it lower down the process cost for cooling purposes. Water
produced is less harmful to the environment since it contains low VOC (Volatile Organic
Compound) number. While for transesterification process, it has been introduced since year
1940 where the chemicals involved are EG and DMT. The process produced methanol as the
byproduct, thus it is crucial to establish recovery unit for methanol. This might increase plant
cost. Transesterification also produce hazardous material where the VOC content is high and
lead to respiratory problem.
ESTERIFICATIO� DETAILS TRA�SESTERIFICATIO�
New Technology - 1963 History Old Technology – 1940
EG + TPA Raw material EG + DMT
Produce H20 By product Produce Methanol
H20 can be recycled for
other usage (Low Cost) Recovery Unit
Need to establish Recovery
Unit (High cost)
No unit required Purification unit Required for methanol recovery
Less harm to environment
(Low VOC content) Environments
Produce hazardous material
(Higher VOC content),
Lead to respiratory problem
Table 1 : Process Comparison
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2.1.4 History, Applications and Usage
PET History
Polyethylene was discovered in 1933 by Reginald Gibson and Eric Fawcett at British
industrial giant Imperial Chemical Industries (ICI). There are two material forms, which is
low density polyethylene (LDPE) and high density polyethylene (HDPE). In early 1950s,
polypropylene (PP) was discovered after the existence of polyethylene. Polypropylene was
invented by two American chemists, who worked for Phillips Petroleum of the Netherlands,
Paul Hogan and Robert Banks. Previously, before PET was introduced, polypropylene is
being used in almost everything ; from plastic bottles to carpets to plastic furniture, and also
heavily used in automobiles.
In year 1941, John Rex Whinfield and James Tennant Dickson, British chemists and
employee of a company named Calico Printer's Association of Manchester, has patented
‘polyethylene terephthalate’ or also known as PET or PETE. It is actually a continuous effort
from early research of Wallace Carothers, who is an American chemist, inventor and the
leader of organic chemistry. Realizing that Carothers's research had not investigated polyester
formed from ethylene glycol and terephthalic acid, Whinfield and Dickson took this
opportunity along with inventors W.K. Birtwhistle and C.G. Ritchiethey to create the first
polyester fiber called Terylene in the same year, 1941.
According to Whinfield and Dickson, polyethylene terephthalate is the basis of
synthetic fibers such as polyester, dacron, and terylene, while the second polyester fiber was
from DuPont's Dacron company. According to DuPont, there was indirect competition with
Britain’s recently formed Imperial Chemical Industries in the late 1920s. Thus, in October
1929, both companies agreed to share information about patents and research developments.
However, even after both companies alliance, DuPont chose to concentrate more on the
promising nylon research. When DuPont resumed its polyester research, ICI had patented
Terylene polyester, to which DuPont purchased the U.S. rights in 1945 for further
development. In 1950, a pilot plant at Seaford, Delaware, was established to produced
Dacron, or polyester fiber with modified nylon technology. Dupont's polyester research lead
23
to a whole range of trademarked products, for example is Mylar (1952), an extraordinarily
strong polyester (PET) film that grew out of the development of Dacron in the early 1950s.
As being mentioned earlier, polyesters are made from chemical substances found
mainly in petroleum and are manufactured in fibers, films, and plastics. According to Dupont
Teijin Films, plain polyethylene terephthalate (PET) or polyester is most commonly
associated with a material from which cloth and high-performance clothing are produced.
Over the last ten years PET has increasingly gained acceptance as a material of choice
especially for beverage bottles. Other that PET, glycolised polyester (PETG) is also being
used in the production of cards. While polyester film (PETF), a semi-crystalline film has
proved its importance in many applications such as videotape, high quality packaging,
professional photographic printing, X-ray film, as well as floppy disks.
PET Application and Usage
Nowadays, polyethylene terephthalate (PET) has been widely used in our daily life, as
it is cheap, flexible, durable, and chemically resistant. As mentioned earlier, two types of
materials formed, which are low density polyethylene (LDPE) and high density polyethylene
(HDPE). LDPE is used to make films and packaging materials, including plastic bags, while
HDPE is used more often to make containers, plumbing, and automotive fittings. In addition,
PET is more impermeable than other low-cost plastics, where this condition has help PET to
become a popular material, especially for making drinking bottles for a giant company, Coke.
PET is also strong and abrasion resistant, and is used for making mechanical parts,
food trays, and other items that have to endure abuse. PET films, which its trade-named is
‘Mylar’ are used to make recording tape. PET manufacturing process has been developed by
using various forming, molding, casting, and extrusion processes, to churn out plastic
products in vast quantities. Other than mentioned PET applications, one of the most visible
parts of this plastics invasion was Earl Tupper's or famously known as ‘Tupperware’. The
Tupperware line of products was well thought out and highly effective, greatly reducing
spoilage of foods in storage. Thin-film "plastic wrap" that could be purchased in rolls also
helped keep food fresh.
24
Another prominent element in 1950s homes was "formica," a plastic laminate that
was used to surface furniture and cabinetry. Formica was durable and attractive. It was
particularly useful in kitchens, as it did not absorb, and could be easily cleaned of stains from
food preparation, such as blood or grease. With formica, a very attractive and well-built table
could be built using low-cost and lightweight plywood with formica covering, rather than
expensive and heavy hardwoods like oak or mahogany. Apart from that, composite materials
like fiberglass came into use for building boats and, in some cases, cars.
From above discussions, PET has been proved that it is widely used in our daily life
as the demand of PET is kept increasing. Thus, PET production plant is become crucial to be
built in Malaysia to cater the needs of recent PET products. Summary of PET usage has been
summarize as per below diagram ;
Figure 2 : Usage of PET
2.2 Product Market Survey
2.2.1 Resources and raw Materials
This project of producing PET is proposed to follow easterification process, where
raw materials involved are ethylene glycol (EG) and terephthalic acid (TPA). Further
explanations on both chemicals are as follows ;
25
Ethylene Glycol (EG)
Below figure emphasized on the world consumption of Ethylene Glocol, where Asia
has falls under top five of EG consumer.
Figure 3 : World Consumption of Ethylene Glycol
By taking Malaysia into considerations, the consumption of EG is also considered
higher. Thus, large amount of EG is needed for various types of industries. Ethylene glycol is
a colorless, odorless, low-volatility, low-viscosity hygroscopic liquid. It is completely
miscible with water and many organic liquids. In industries, there are at least five grades of
ethylene glycol are manufactured, which include commercial polyester, industrial, low
conductivity, polyester, and antifreeze.
Figure 4 : Usage of Ethylene Glycol
26
Referring to Figure 4, in 2009, almost 85% of the ethylene glycol (EG) is consumed
worldwide into the production of PET, which in turn was converted into fibers, film and
bottles. Another 10% was consumed in antifreeze and 5.5% in other uses. In 2009, 69% of
the EG consumed worldwide was in Asia, followed by 13% in North America and 8% in
Western Europe. With the huge amount needed for PET production, EG production must also
be increase from time to time to catch up with its consumption.
Terephthalic Acid (TPA)
Consumption of TPA for the production of PET polymer has been more than 90% of
the worldwide consumption. The following pie chart shows world consumption of TPA ;
Figure 5 : World Consumption of TPA
By taking the year of 2009 as TPA based world consumption, more than 60% of the
TPA produced in the world is used to manufacture PET polymer for polyester fibers. Another
31% goes into the manufacture of PET solid-state resin for bottles and other packaging
applications.
27
Figure 6 : TPA World Consumption In Year 2009
TPA for PET solid-state resins has grown strongly followed by the replacement of
glass in soft drinks and water bottles. In five years, PET solid-state resins are estimated to be
the fastest-growing sector in the next five years. Referring to Figure 4, Asia falls under fifth
major contributor to consume TPA, where the opportunity to set up PET production plant is
being study in Malaysia.
2.2.2 Global Market Outlook
PET packaging resin markets have seen very strong growth over the last 20 years. It
first penetrated the carbonated soft drinks market because it is lightweight and strong. PET
bottles are virtually unbreakable while a typical 1.5 litre bottle weighs about 40-45gm, about
one-tenth the weight of glass. PET has taken market share in the bottled water market due to
its good clarity and not leaving any taste in the water. It has also found applications in more
niche markets such as sports drinks and fruit juices, and is used to make bottles for cooking
and salad oils, sauces and dressings.
An untapped market for PET is beer packaging with substantial conversion where it
has captured 5% of the beer market, 62% of glass and 33% of metal cans, according to
Canadean, the UK-based beverage research consultant, while the largest market is Russia,
which accounts for 60% of PET’s use in the global beer market. Other east European
countries are prominent users, but outside these countries, only Germany, South Korea and
Spain make any significant contribution to PET use for beer packaging.
28
The highest demand for PET is Asia, which its demand by volume for PET in 2009
was nearly 4.7 million tons, while Europe is the second largest consumer of PET in the
world. Russia, Italy and Germany are the major consuming countries in Europe. The demand
in some Western European countries, such as Germany, France, Spain and the UK, is
approaching the maturity stage. Growth in European PET demand is driven mostly by Russia.
The demand for PET in Europe was around 3.7 million tons in 2009. The North American
economy is the most developed and advanced, and the scope for growth is lowest as the
demand is close to saturation. However, certain new and upcoming applications of PET are
driving the North American market. The North American demand for PET in 2009 was close
to 3.1 million tons in 2009. The PET demand in South and Central America is growing fairly
strongly. This region consumed around 2 million tons of PET in the year 2009. The Middle
East and African demand for PET is the second fastest growing after that of Asia. The Middle
East and Africa region consumed around 1.2 million tons PET in 2009.
Then again, factor that could impact the supply and demand balance for PET is the
growth in recycling. PET is probably the most recycled polymer taken and being increasingly
used in bottles and retail packaging as well as carpet fiber and clothing. Still, the Global
Market outlook for PET is expected to grow based on the global demand for over the last
decade. The global PET market in 2009 was about 15.3 million tons. In the year of 2020, the
consumption demand for PET is estimated to grow at CAGR of 4.9%.
2.2.3 Asian Market Outlook
Based on Figure 7 on the demand shares by region, shows that Asia is the biggest
consumer of PET with 30.5%, followed by Europe 24%, North America 20.3%, South and
Central America 13.4%, Middle East and Africa 8% and other region is about 3.7%. Thus, it
makes the highest demand for PET is Asia, which its demand by volume for PET in 2009 was
nearly 4.7 million tons.
29
Since the growth in PET demand is coming from Asia, the Gross Domestic Product
(GDP) countries like China and India in Asia are growing at rates higher than the global GDP
growth rates. Thus, the key markets consuming PET are also growing with strong economic
growth along large population that enables large consumption of Carbonated Soft Drinks
(CSDs) and bottled water in the region. Another factor that supports PET demand is rapid
changing of lifestyle that consumes packaged food.
In Asia, China is the largest producer of PET in the region and exports to many
countries as well as the largest PET consuming markets are Carbonated Soft Drinks (CSD)
and Bottled Water. This is due to its light weight, toughness and clarity, PET is the most
preferred material for CSD bottles. CSD and bottled water together account for more than
65% of the global PET demand. However, the packaged food segment is also a very
important and growing market for PET.
Figure 7 : Global PET Demand by Regions
30
2.2.4 Overall Market Outlook
Development and growth of the global PET solid-state resin market since 1996 has
been impressive after their thirty-two years of introduction in the mid-1970s. Global
consumption of these resins continues to grow especially in these three regions ; North
America, Europe and Asia, which accounted for the majority of world production and
consumption. Asia and Middle East are expected to achieve double-digit consumption growth
through 2012, while Eastern Europe and South America have created import opportunities.
Asian and Middle Eastern producers are expected to be the major suppliers of PET exports to
Eastern Europe, Central and South America, and Oceania as its continuous production and
relatively lower feedstock costs as the primary drivers.
The following pie chart shows world consumption of PET solid-state resins:
PET bottle resin is a very important material driving growth in the developed
economies, but growth of PET fiber remains dominant in terms of total polyester. PET
growth is driven differently depending on the geographic region. In North America and
Western Europe, PET growth is associated primarily with PET bottle resins; demand for PET
fiber has been in decline since the late 1990s. PET growth in most other regions is primarily
associated with PET fiber. Global polyester growth will continue to be driven by Asia and,
more specifically, by the Chinese market.
Figure 8 : World Consumption of PET Resins
31
2.2.5 Overall Production Estimation
To estimate the production capacity of a new polyethylene terephthalate (PET) plant,
we assume that the production capacity of world depends largely on the world population. In
2015, the world population is estimated to be around 6.8 billion people. We assume that we
want to produce PET solely in Malaysia. To estimate the amount of PET to produce, we need
to do a calculation based on the population in Malaysia and the world’s population.
Based on “Catalytic and Mechanistic Studies of PET Synthesis” by Faissal-Ali El-Toufaili, in
2015, the PET demand in 2015 is about 58 x 106 MT/yr.
Calculation:
32
Site Feasibility Study
2.2.6 Introduction
Choosing strategic plant location is one of the most crucial decisions needs to be
done. The construction of a chemical plant requires a preliminary feasibility study to be done
in order to make certain that the proposed 30,000 kg/year PET plant is feasible, economically
and environmentally. The location of the plant site takes relatively high precedence and it
mainly depends on the availability of feedstock, cost of production, marketing of the
products, land availability and also the infrastructure. The right location allows maximum
profit with a minimum operating cost and allowance for future expansion.
2.2.7 Selection Criteria
Based on the study done in the selecting strategic plant location, there are several
factors that should be taken into consideration when undertaking the process of selecting a
suitable site. There are two major factors that contribute to the operability and economic
aspects of a site location for a plant, which are the primary factor and specific factor.
Table 2 : Contributing Factors to Operability and Economy Aspects
Primary Factors Specific Factors
1. Raw material availability for
industry
Availability of low cost labor and
services
2. Reasonable land price Safety and environmental impacts
3. Source of utilities, such as
electricity, water and etc.
Incentives given by government :
Pioneer Status
Investment Tax Allowance (ITA)
Effluent and waste disposal facilities
4. Climate status
Wind
Rainfall
Temperature
Relative Humidity
Transportation facilities
Local community consideration
33
2.2.8 Contributing Factors in Site Selection
General Factors
i. Availability of Raw Material
To minimize the transportation cost of the raw material, a closer source of the
raw material to the operating plant is needed. If the needed raw material is to be
imported, it would be important to consider a location near to a seaport with excellent
infrastructure.
ii. Reasonable land price
Most of the industrial land price depends on the location. It is very important
to choose an economical land price which can reduce the total investment cost.
Besides that, it is important to choose the lowest land price when starting a new plant
to gain the highest economic value.
iii. Utilities
In petrochemical industries, large quantities of water supply are usually
needed for cooling and general use in a chemical plant. Besides that, petrochemical
plants need power in the form of electricity to run machines and equipments. Thus it
is important to have sufficient power and local water supply in order to ensure the
plant running smoothly.
iv. Climate
Budget and cost operation can be affected by climatic conditions. A general
analysis of the yearly weather conditions would be an important consideration.
34
Specific Factors
i. Availability of low cost labor and services
Plant should be located where sufficient labor supply is available. Skilled
construction workers will usually be brought in from outside local area but there
should be an adequate pool of unskilled workers available locally and workers
suitable for training to operate the plant. Available, inexpensive manpower from the
surrounding area will contribute in reducing the cost of operation.
ii. Transport facilities
The plant should be located close to at least three forms of major
transportation facilities, which are road network, seaport and airport. These will help
facilitate any import and export activities. Seaport facilities will help in the
exportation and importation of the product and raw materials via tankers while the
availability of airport is convenient for the movement of personnel and essential
equipment supplies.
iii. Government incentives
Most state governments offer attractive incentives to investors. Some
incentives grant partial or total relief from income tax payment for a specified period,
while indirect tax incentives come in the form of exemptions from import duty, sales
tax and excise duty. This can help reduce initial operating costs.
iv. Local community consideration
The proposed plant will have to fit in with and acceptable to the local
community. Full consideration must be given to be safe location of the plant so that it
does not impose a significant additional risk to the community. On a new site, a local
community must be able to provide adequate facilities for the plant personnel: school,
banks, housing, and recreational and cultural facilities.
35
v. Waste and effluent disposal facilities
Site selected should have efficient and satisfactory disposal system for factory
waste and industrial effluent if it is decided that the waste should be treated off-site.
2.2.9 Summary Of Characteristic at Each Location
The manufacture of PET is categorized as a petrochemical project. The plant must
therefore be sited in a special zone provided by the government. After conducting the
feasibility and site survey, four (4) main locations have been short listed to be considered as
strategic site location for the construction of a 30,000 kg/year, PET plant.
i) Kerteh Industrial Estate,Terengganu
Kertih Integrated Petrochemical Complex, Terengganu located at the south of
Terengganu, is developed by PETRONAS. Plants can be sited within the vicinity of
raw materials thus saving in production cost. Availability of cheap industrial land and
supply of relatively productive and adaptable labor from a young and literate
population give merit to the location. Special incentives are offered such as cheaper
land and lower quit rent and assessment rates. Terengganu is also home of the
Malaysia deepest port versioned to be the new gateway to the Asia Pacific.
ii) Gebeng (Phase IV) Industrial Estates, Kuantan, Pahang.
Gebeng Industrial Estate is promoted by the Pahang State Development
Corporation (PSDC) as an industrial predecessor in the East Asian region for
petrochemical and chemical based plants. The federal government’s move to develop
the eastern industrial corridor ensures beneficial and rapid progression for the
industrial growth of Gebeng estate. According to Kuantan Port Consortium (2007),
the first and second phase category, comprises about 900 hectares. A third phase,
spanning some 1,600 hectares, has attracted mega industries from multinational
companies, namely from the US, Japan, Germany and Belgium. Kuantan proximity to
Malaysia’s oil and gas fields make it a logical choice for petrochemical industry
growth.
36
iii) Teluk Kalong Industrial Estate, Terengganu.
Teluk Kalong is an industrial town of Kemaman district, Terengganu,
Malaysia. Teluk Kalong insdustrial Estate was built by Terengganu State through
Perbadanan Memajukan Iktisad Negeri Terengganu (PMINT) to support petroleum
industry at Terengganu. It is located at strategic location which is 35 minutes to
Gebeng Kuantan Industrial Area and 40 minutes to Kerteh Industrial Area.
iv) Pasir Gudang, Industrial Estate,Johor.
Pasir Gudang, Industrial Estate is located 36 km from Johor Bahru. The type
of industry develop in Pasir Gudang is light, medium and heavy industry. Johor Port
is about 5 km from Pasir Gudang, and this will enable easier import and export
processes. Good infrastructure facilities are also available here, such as North-South
highway to Kuala Lumpur and the main road to Singapore. Railroads are also
available here. The line runs from northern terminal in Butterworth to Singapore and
Pasir Gudang in the South.
Evaluation for each site location was made which is based on primary and specific
factor which had been justified earlier. Summary of justification can be seen in Table 2 and
Table 3.
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39
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ts
Pio
nee
r S
tatu
s an
d I
nves
tmen
t
Tax
All
ow
ance
an
d
Rei
nves
tmen
t A
llo
wan
ce.
Pio
nee
r S
tatu
s an
d
Inves
tmen
t T
ax A
llo
wan
ce
and
Rei
nves
tmen
t
All
ow
ance
.
Pio
nee
r S
tatu
s an
d
Inves
tmen
t T
ax A
llo
wan
ce
and
Rei
nves
tmen
t
All
ow
ance
.
Pio
nee
r S
tatu
s an
d I
nves
tmen
t
Tax
All
ow
ance
an
d
Rei
nves
tmen
t A
llo
wan
ce.
Ince
nti
ves
fo
r h
igh
tec
h
ind
ust
ries
Ince
nti
ves
fo
r h
igh
tec
h
ind
ust
ries
Ince
nti
ves
fo
r h
igh
tec
h
ind
ust
ries
Ince
nti
ves
fo
r h
igh
tec
h
ind
ust
ries
Lo
cal
peo
ple
(15
-30
yea
rs o
ld)
65
0 0
00
peo
ple
s 3
50
00
0 p
eop
les
65
0 0
00
peo
ple
s 1
50
0 0
00
peo
ple
s
Wa
ste
wa
ter
ma
na
gem
ent
Ku
alit
i A
lam
Sd
n B
hd
, B
ukit
Nen
as, N
eger
i S
emb
ilan
Ind
ah W
ater
Kon
sort
ium
Ku
alit
i A
lam
Sd
n B
hd
,
Bu
kit
Nen
as, N
eger
i
Sem
bil
an
Ind
ah W
ater
Kon
sort
ium
Ku
alit
i A
lam
Sd
n B
hd
, B
ukit
Nen
as, N
eger
i S
emb
ilan
Ind
ah W
ater
Kon
sort
ium
Ku
alit
i A
lam
Sd
n B
hd
, B
ukit
Nen
as, N
eger
i S
emb
ilan
Ku
alit
i A
lam
Sd
n B
hd
Sel
ecti
on
:
Ker
teh
In
du
stri
al
Est
ate
40
Ta
ble
4 :
Wei
gh
ted
ma
rk
s a
nd
ex
pla
na
tio
n o
n t
he
pla
nt
site
lo
cati
on
fa
cto
rs
Fa
cto
rs:
7 –
10
Ma
rks
4 –
6 M
ark
s 0
– 3
Mark
s
Su
pp
ly o
f ra
w m
ate
rial
•
Ab
le t
o o
bta
in l
arge
sup
ply
lo
call
y
thu
s sa
vin
g o
n i
mp
ort
co
st.
•
Hav
ing l
on
g p
ipel
ine
net
work
s fo
r th
e tr
ansp
ort
atio
n o
f ra
w m
ater
ials
.
•
So
urc
e o
f ra
w m
ater
ials
fro
m
nei
ghb
ou
rin
g s
tate
s o
r co
untr
ies
wit
h t
he
dis
tance
not
exce
edin
g
80
km
.
•
Use
s a
pip
elin
e sy
stem
as
wel
l.
•
Un
able
to
obta
in r
aw m
ater
ial
fro
m c
lose
so
urc
es w
ith
th
e d
ista
nce
exce
edin
g 8
0k
m.
•
Fo
rced
to
im
po
rt f
rom
fo
reig
n
cou
ntr
ies
•
Use
a p
ipel
ine
syst
em a
s w
ell.
Pri
ce a
nd
are
a o
f la
nd
•
Lan
d a
rea
ex
ceed
ing 6
0 h
ecta
res
•
Pri
ce o
f la
nd
bel
ow
RM
20 p
er m
2
•
Lan
d a
rea
bel
ow
60
hec
tare
s
•
Pri
ce o
f la
nd
mo
re t
han
RM
20
p
er m
2
•
Lan
d a
rea
bel
ow
40
hec
tare
s
•
Pri
ce o
f la
nd
ex
ceed
ing R
M3
0 p
er
m2
Lo
cal
Go
ver
nm
ent
Ince
nti
ves
•
Ince
nti
ves
fro
m t
he
Loca
l O
rgan
izat
ion o
f C
oun
try
Dev
elop
men
t
•
Ince
nti
ves
fro
m s
pec
ial
com
pan
y
•
Ince
nti
ves
fro
m t
he
Loca
l O
rgan
izat
ion o
f C
oun
try
Dev
elop
men
t.
•
No
in
cen
tives
fro
m t
he
Lo
cal
Org
aniz
atio
n o
f C
oun
try
Dev
elop
men
t.
Tra
nsp
ort
ati
on
•
Co
mp
lete
n
etw
ork
an
d
wel
l m
ain
tain
ed h
igh
way
s, ex
pre
ssw
ays
and
road
s.
•
Inte
rnat
ion
al
Air
port
fa
cili
ties
ac
cess
to
th
e m
ain
lo
cati
ons
aro
un
d
the
worl
d.
•
Lo
cati
on
nea
r to
inte
rnat
ion
al p
ort
w
ith
im
po
rt a
nd
exp
ort
act
ivit
ies.
•
Rel
iab
le
rail
way
li
nes
to
re
mo
te
area
s n
ot
acce
ssib
le b
y r
oad
s.
•
Go
od
fed
eral
ro
ad a
nd
hig
hw
ay
syst
ems
•
Lim
ited
rai
lway
syst
em a
cces
s
•
Mo
re d
ista
nt
fro
m t
he
port
s
•
Air
port
fac
ilit
ies
wh
ich
may
no
t h
ave
inte
rnat
ion
al f
ligh
t fa
cili
ties
– o
nly
pro
vid
ing
do
mes
tic
flig
hts
.
•
Aver
age
road
syst
ems
•
No
hig
hw
ay o
r ex
pre
ssw
ay
syst
em i
n c
lose
pro
xim
ity.
•
No
rai
lway
syst
em.
•
Ver
y d
ista
nt
fro
m t
he
po
rts
or
har
bors
.
•
Dis
tan
t fr
om
th
e nea
rest
air
po
rt –
m
ore
th
an 1
00
km
aw
ay.
Table 5 : Weight Matrix On Site Location
Criteria Kerteh Gebeng Teluk
Kalong Pasir Gudang
Supply of raw material 6 6 7 3
Price and area of land 7 6 7 3
Local government incentives 8 8 8 8
Transportation 9 7 8 7
Workers supply 6 5 6 8
Utilities, water and electricity 8 6 7 7
Type of industrial and its
location
8
8
6
6
Waste water disposable 8 8 8 7
Total 60/80 54/80 57/80 49/80
75.00% 67.5% 71.25% 61.25%
2.2.10 Concluding Remark
Based on the matrix comparison made, Kerteh Industrial Estate has been chosen as
the site for the PET plant. The location of Kerteh Industrial Estate is highly strategic
compared to others where the reason is focused on the nature and the requirements of the
plant ;
• Kerteh industrial estate is situates at east coast of peninsular Malaysia and it is
only 9 km from Paka and 7 km from Kerteh.
• Low land prices compared to other location, which is at RM 1.94 – 60.26 per
metre square.
• Since this location if near the Kerteh Port, Kuala Terengganu port, and Kemaman
port, any trade involving the import and export of products and, if necessary, raw
materials can be achieved with relative ease
42
• Attractives incentives given by the Malaysia government and local government
which is :
� Infrastructure Allowance.
� Five-year exemption on import duty.
� 5 % discount on monthly electrical bills for first 2 years.
� 25-38 % exemption on daily water cost for 4545 m3 of water for 2 years
� Pioneer Status and Investment Tax Allowance and Reinvestment Allowance.
� 85% tax exemption on gross profit
• Constant supply of utilities such as cooling water, power supply and waste
management.
� Power supply : Tasik Kenyir Hydroelectric Dam , IPP YTL (600 MW) , IPP
YTL (600 MW), Paka Power plant (900 MW) and CUF Kertih
� Water supply : Bukit Sah ,Sungai Cherol ,Sungai Kemasik , and CUF Kerteh
� Waste management: Kualiti Alam Sdn Bhd Bukit Nenas, Negeri Sembilan and
Indah Water Konsortium
• Excellent transportation link by railway, road and airpot. Kerteh is connected to
Kuala Terengganu, Gebeng and Kuantan via main road and also railway.
Good pipeline connection between Gebeng, Kuantan, and Kerteh. Transportation
of raw material had been eased by the connection of pipeline between these two
petrochemical industrial plants. A good network of pipe racks is crucial as it creates for a
cheaper and efficient method in transporting chemicals from designated plants to the port. In
addition, a Centralized Utility Facilities (CUF) is also offering its services to plant owners in
Kerteh to provide the supply of electricity, industrial gases and utilities such as steam and
pretreated water.
43
2.3 Physical and Chemical Properties
2.3.1 Polyethylene Terephthalate (PET)
Molecular Structure :
Table 6 : PET Properties
2.3.2 Ethylene Glycol (EG)
Molecular Structure :
Table 7 : EG Properties
Properties Values
Formula (C10H8O4)n
Molecular weight Depends on n number
Density 1.4 g/cm3
Melting point 260 °C
Boiling Point ~930 °C
Colour Colourless
Physical state Solid
Properties Values
Formula C2H6O2
Molecular weight 62.1
Density 1.11 g/cm3
Melting point -13 °C
Boiling Point 198 °C
Colour Clear liquid
Physical state Liquid
44
2.3.3 Diethyl Glycol (DEG)
Molecular Structure :
Table 8 : DEG Properties
2.3.4 bis-hydroxyethyl terephthalate (BHET)
Molecular Structure :
Table 9 : BHET Properties
Properties Values
Formula C4H10O3
Molecular weight 106.12
Density 1.12 g/cm3
Melting point -10.45 °C
Boiling Point 245 °C
Colour Colourless
Physical state Liquid
Properties Values
Formula C12H14O6
Molecular weight 254.2
Density 1.34 g/cm3
Melting point 110 °C
Boiling Point 409.9 °C
Colour Colourless
Physical state Liquid
45
2.3.5 Terephthalic Acid (TPA)
Molecular Structure :
Table 10 : TPA Properties
2.3.6 Water
Molecular Structure : H – O – H
Table 11 : Water Properties
Properties Values
Formula C8H6O4
Molecular weight 166.14
Density 1.52 g/cm3
Melting point 300 °C
Boiling Point sublimes
Colour White Crystal Powder
Physical state Solid
Properties Values
Formula H2O
Molecular weight 18.02
Density 1.00 g/cm3
Melting point 0 °C
Boiling Point 100 °C
Colour Colourless
Physical state Liquid
46
2.4 Feedstock Supply
2.4.1 Supplier Profile
OPTIMAL GLYCOLS (MALAYSIA) SD� BHD
The Company was established in July 1998 to develop a world class integrated
petrochemical facility in Kertih, Terengganu, Malaysia. Centered within the PETRONAS
Petroleum Industry Complex, Malaysia’s most sophisticated and advanced petrochemical
facility, the OPTIMAL GLYCOLS (MALAYSIA) SDN BHD is located 3 km from Pekan
Paka and 10 km from Kerteh.
OPTIMAL GLYCOLS (MALAYSIA) SDN BHD produces three main products ie.
Mono-Ethylene Glycol (MEG), Di-Ethylene Glycol (DEG) and Re-Distilled Ethylene Oxide
(RDO), using world-renowned EOG METEOR™ Technology from Dow, the most advanced,
efficient and cost competitive technology for the production of MEG, DEG and high purity
EO for derivatives.
Both, MEG (the largest volume product manufactured by OPTIMAL GLYCOLS) and
DEG are sold within Malaysia and to various countries throughout the Asia Pacific region.
OPTIMAL Glycols (M) Sdn Bhd is a wholly owned subsidiary of Petronas.
*NOTE: kTa: Kilo Metric Ton Per Annum (1000 MTY)
Products & Production Capacity of OPTIMAL GLYCOLS (M) SD� BHD:
Products kTa
Mono-Ethylene Glycol (MEG) 365
Di-Ethylene Glycol (DEG) 20
Re-Distilled Ethylene Oxide (RDO) 140
47
BP Amoco SD� BHD
The purified terephthalic acid (PTA) plant is located in the State of Pahang on the east
coast of the Malaysia peninsula, 25 km from Kuantan town. This BP wholly owned unit
began production in 1996 with an annual PTA capacity of 600,000 tons. Shipments are made
by truck, bulk containers, and FIBC bags.
The Kuantan plant employs over 270 full-time residents and 150 contractors.
Commissioned in 1996, the plant had received ISO 9002 certification in 1998 and ISO 14001
in 2001. The site had achieved many awards including the 1999 National Occupational Safety
& Health Award, the Prime Minister Hibiscus Award 2000/2001 for Exceptional
Achievement in Environmental Performance, National OSH Award 2001 for Transportation,
Logistics & Communications.
48
CHAPTER 3 : PRELEMI�ARY HAZARD A�ALYSIS
3.1 Safety Issues and Preliminary Hazard Analysis
Development of a complete plant design involves consideration of many different
topics .The overall picture of designing involves extensive study of engineering including the
most important parameter beside economic is the safety.
Chemical handling, processing and storing consist of many safety issues. The hazard
may simply come from storage of the chemicals and towards the reaction of the chemicals
itself. Hazards existed in some chemical because of its natural behavior to explode or react
dynamically with or without any external factors. Potential hazard will depend on inherent
toxicity of materials and also inherent toxicity of the materials frequency and duration of any
exposure .It is essential for designer to aware of these hazards and develop a design that will
minimize the potential hazards as minimum as possible.
This chapter will emphasize the important of Preliminary Hazard Analysis which
include identification and assessment of hazards and general safety procedure. Some of the
topic that will be included in this chapter are particular hazard for each chemical and law
requirement in Malaysia regarding set up a process plant in Malaysia.
3.2 Identification of Material and Chemical Hazard
The chemicals that are used in our process are listed as below:
Feed • Terephthalic acid
• Ethylene Glycol
Product • BHET
• PET
Byproducts • DEG
• AA
Catalyst • Antimony Trioxide
Fro
m a
ll o
f m
ater
ial
and
ch
emic
al i
nv
olv
ed i
n t
he
pro
du
ctio
n,
cert
ain
cri
tica
l fa
cto
rs m
ust
be
anal
yze
d f
rom
eac
h M
ater
ial
Saf
ety D
ata
Sh
eets
(M
SD
S)
as i
n t
he
Tab
le 1
4 ;
Ma
teri
al
Hea
lth
Aff
ect
Fir
e a
nd
Ex
plo
sion
C
orr
osi
vit
y
Sta
bil
ity
an
d
Rea
ctiv
ity
T
ox
icit
y
TP
A
Haz
ard
ou
s in
cas
e o
f sk
in
con
tact
(ir
rita
nt)
, o
f ey
e
con
tact
(ir
rita
nt)
, o
f
inges
tio
n,
of
inh
alat
ion
(lu
ng i
rrit
ant)
. R
epea
ted
or
pro
lon
ged
ex
po
sure
to
th
e
sub
stan
ce c
an p
rod
uce
targ
et o
rgan
s d
amag
e
May
be
flam
mab
le i
n
hig
h t
emp
erat
ure
N
ot
Av
aila
ble
N
ot
Av
aila
ble
Th
e su
bst
ance
is
tox
ic t
o b
loo
d,
kid
ney
s, l
iver
, b
lad
der
, b
rain
,
card
iov
ascu
lar
syst
em,
eyes
,
Nu
trit
ion
al a
nd
Gro
ss
Met
abo
lic,
ear
s, n
ose
/sin
use
s,
thro
at
Eth
yle
ne
Gly
col
Haz
ard
ou
s in
cas
e o
f
inges
tio
n.
Sli
gh
tly
haz
ard
ou
s in
cas
e o
f sk
in
con
tact
(ir
rita
nt,
per
mea
tor)
, o
f ey
e co
nta
ct
(irr
itan
t),
of
inh
alat
ion
. S
ever
e o
ver
-
exp
osu
re c
an r
esu
lt i
n
May
be
flam
mab
le i
n
hig
h t
emp
erat
ure
No
n-c
orr
osi
ve
in p
rese
nce
of
gla
ss
Inst
abil
ity w
hen
ex
cess
hea
t an
d i
nco
mp
atib
le
mat
eria
ls.
Rea
ctiv
ity
spec
ial
rem
ark
s:
Hyg
rosc
op
ic.
Ab
sorb
s
mo
istu
re f
rom
th
e ai
r.
Av
oid
co
nta
min
atio
n
wit
h m
ater
ials
wit
h
Ch
ron
ic e
ffec
ts:M
uta
gen
ic f
or
mam
mal
ian
so
mat
ic c
ells
. N
on
-
mu
tagen
ic f
or
bac
teri
a an
d/o
r
yea
st.
May
cau
se d
amag
e to
th
e
foll
ow
ing o
rgan
s: k
idn
eys,
liv
er,
cen
tral
ner
vo
us
syst
em
(CN
S).
50
dea
th.
hyd
rox
yl
com
po
un
ds.
Als
o i
nco
mp
atib
le
wit
h a
lip
hat
ic a
min
es,
iso
cyan
ates
,
chlo
rosu
lfo
nic
aci
d,
and
ole
um
PE
T
Irri
tati
ng t
o e
yes
,
resp
irat
ory
syst
em a
nd
sk
in
N/A
n
/a
No
fla
h p
oin
t d
ata
bu
t
avo
id t
emp
erat
ure
abo
ve
23
5 °
An
tim
on
y
Tri
ox
ide
Haz
ard
ou
s in
cas
e o
f sk
in
con
tact
(ir
rita
nt,
sen
siti
zer)
,
of
eye
con
tact
(ir
rita
nt)
, o
f
inges
tio
n,
of
inh
alat
ion
No
n-f
lam
mab
le.R
isk
of
exp
losi
on
wh
en
pre
sen
ce o
f st
atic
dis
char
ge
No
n c
orr
osi
ve
in p
rese
nce
of
gla
ss
Sta
ble
carc
ino
gen
ic e
ffec
ts:
Cla
ssif
ied
A2
(S
usp
ecte
d f
or
hu
man
.) b
y
AC
GIH
. C
ause
s d
amag
e to
th
e
foll
ow
ing o
rgan
s: l
un
gs,
mu
cou
s m
emb
ran
es.
Ta
ble
14
: M
SD
S f
or
Sel
ecte
d C
hem
ica
l
51
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
Red
uce
Inv
ento
ries
Rea
cto
r •
Ov
er p
ress
uri
zati
on
du
e to
vap
ori
zati
on
of
liq
uid
bec
ause
of
hig
h e
ner
gy r
elea
se.
•
Ov
erh
eate
d c
on
dit
ion
sin
ce t
he
rem
ov
al o
f
hea
t p
rod
uce
d i
s le
ss t
han
its
co
oli
ng r
ate,
wh
ere
pre
ssu
re w
ill
incr
ease
as
tem
per
atu
re
chan
ge.
•
Rat
e o
f te
mp
erat
ure
ris
e w
ill
be
fast
er o
nce
hea
t gen
erat
ion
ex
ceed
s th
e av
aila
ble
co
oli
ng
cap
acit
y.
•
Ch
oo
se c
on
tin
uo
us
or
sem
i b
atch
op
erat
ion
sin
ce b
atch
op
erat
ion
req
uir
es l
arg
e in
ven
tory
saf
ety i
nce
nti
ve.
•
Ov
erp
ress
ure
rel
ief
pro
tect
ion
su
ch a
s ru
ptu
re d
isk
,
pre
ssu
re s
afet
y v
alv
e, o
r co
mb
inat
ion
of
the
two
is
nee
ded
fo
r th
e re
acto
r.
•
Pro
per
pro
cess
co
ntr
ol
syst
em t
o a
vo
id o
ver
hea
ted
an
d
ov
er p
ress
uri
zati
on
co
nd
itio
ns
at t
he
reac
tor.
•
Fo
r re
acto
r w
ith
ru
naw
ay r
eact
ion
, th
e se
t p
ress
ure
of
the
safe
ty v
alv
e o
r ru
ptu
re d
isk
sh
ou
ld b
e cl
ose
to t
he
no
rmal
op
erat
ing p
ress
ure
as
po
ssib
le.
Dis
till
atio
n
•
Hig
h p
ress
ure
may
cau
se f
loo
din
g.
•
Lar
ge
inv
ento
ries
of
bo
ilin
g l
iqu
id,
som
etim
es u
nd
er p
ress
ure
, in
th
e d
isti
llat
ion
colu
mn
bo
th i
n t
he
bas
e an
d h
eld
up
.
•
Sel
ect
suit
able
seq
uen
ce t
hat
ten
ds
to m
inim
ize
the
flo
wra
te o
f n
on
key
co
mp
on
ents
.
•
Use
su
itab
le c
olu
mn
to
red
uce
th
e in
ven
tory
as
wel
l as
po
ten
tial
lea
kag
e p
rob
lem
.
•
Ov
erp
ress
ure
rel
ief
syst
em i
s n
eed
ed.
52
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
Hea
t
Tra
nsf
er
Op
erat
ion
•
Co
mm
on
saf
ety p
rob
lem
s in
clu
de
tub
e
rup
ture
, le
akin
g,
fou
lin
g,
tub
e v
ibra
tio
n,
po
lym
eriz
atio
n,
and
so
lid
ific
atio
n.
•
Fai
lure
s in
hea
t ex
chan
ger
s re
sult
in
pre
ssu
re
chan
ges
an
d c
on
tam
inat
ion
of
the
hea
t
tran
sfer
, fl
uid
or
pro
cess
flu
id.
•
Fla
mm
able
mat
eria
ls n
eed
s to
be
sub
stit
ute
wit
h l
ess
or
no
n-f
lam
mab
le m
ater
ials
.
•
Les
s h
azar
do
us
refr
iger
ant
flu
id u
sed
at
low
pre
ssure
op
erat
ion
may
lea
d t
o m
ajo
r h
azar
d, b
ut
it i
s al
low
able
wh
en t
he
pro
cess
is
at h
igh
er p
ress
ure
.
•
Do
ub
le t
ub
e sh
eets
are
rec
om
men
ded
fo
r h
igh
ly t
ox
ic
mat
eria
ls.
•
Ov
erp
ress
ure
rel
ief
is n
eed
ed f
or
pro
tect
ion
of
hea
t
exch
ang
ers
agai
nst
eff
ect
of
tub
e ru
ptu
re
Ch
em
ica
l R
eact
ion
•
Wh
en m
ore
haz
ard
ou
s co
mp
on
ents
in
vo
lve
in c
hem
ical
rea
ctio
n,
mo
re h
azar
do
us
con
dit
ion
(e.
g.
exp
losi
on
, ac
cid
ent
etc)
may
occ
ur.
•
Sel
ect
pro
cess
ro
ute
th
at i
nv
olv
es l
ess
haz
ard
ou
s
chem
ical
s.
•
If s
ub
stit
uti
on
is
no
t p
oss
ible
, is
ola
tio
n o
f th
e pro
cess
fro
m t
he
wo
rker
s is
nec
essa
ry.
Ch
em
ica
l S
tora
ge
•
Ch
emic
al l
eak
age
fro
m s
tora
ge
tan
k c
an l
ead
to v
apo
r cl
ou
d a
nd
to
xic
clo
ud
.
•
Imp
rop
er c
hem
ical
sto
rage
and
flo
w c
on
tro
l
may
lea
d t
o t
he
po
ssib
ilit
ies
of
exp
losi
on
of
the
sto
rage
equ
ipm
ents
sin
ce m
ost
ch
emic
als
bei
ng s
tore
d a
re f
lam
mab
le.
•
Sto
rage
equ
ipm
ents
nee
d t
o b
e at
a l
ow
tem
per
atu
re,
wel
l v
enti
late
d a
rea,
un
der
an
atm
osp
her
e o
f d
ry
nit
rogen
, an
d a
way
fro
m s
ou
rces
of
fire
haz
ard
.
•
Usa
ge
of
clo
sed
sp
her
ical
or
cyli
nd
rica
l ta
nk
s to
pre
ven
t th
e es
cap
es o
f v
ola
tile
s an
d m
inim
ize
con
tam
inat
ion
.
53
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
•
Ch
emic
als
that
lea
k c
an f
low
to
ele
ctri
cal
com
po
nen
t, w
hic
h i
s a
sou
rce
of
ign
itio
n t
hat
may
lea
d t
o e
xp
losi
on
.
•
Sto
rage
tan
k m
ay e
asil
y c
orr
od
e si
nce
th
e
chem
ical
s b
ein
g s
tore
d a
re m
ost
ly c
orr
osi
ve.
•
To
mai
nta
in t
he
pre
ssu
re o
f st
ora
ge
tan
k, p
ress
ure
safe
ty v
alv
e sh
ou
ld b
e in
stal
led
on
top
of
it.
Vap
ors
that
sh
ou
ld b
e v
ente
d f
rom
th
e ta
nk
mu
st b
e se
nt
to t
he
inci
ner
ato
r in
stea
d o
f at
mo
sph
ere.
•
Ven
t sh
ou
ld b
e p
osi
tio
ned
so
th
at t
he
ou
tlet
s ca
use
th
e
leas
t p
oss
ible
co
nta
min
atio
n t
o t
he
wo
rkin
g
atm
osp
her
e o
r an
y n
eigh
bo
uri
ng l
oca
tio
n.
•
Eq
uip
men
t fo
r st
ora
ge
tan
k n
eed
to
be
mad
e fr
om
gla
ss, p
oly
eth
yle
ne,
po
lyp
rop
yle
ne,
or
stai
nle
ss s
teel
.
Mat
eria
l o
f C
on
stru
ctio
n
•
Usa
ge
of
po
or
mat
eria
ls m
ay l
ead
to
lea
kag
e,
rup
ture
, co
rro
sio
n,
or
exp
losi
on
.
•
Usa
ge
of
carb
on
ste
el c
an l
ead
to
co
rro
sio
n
wh
en c
orr
osi
ve
com
po
nen
ts f
low
th
rou
gh
it.
•
Hig
h
pre
ssu
re
pro
cess
w
ith
in
ves
sels
an
d
colu
mn
s m
ay c
ause
cra
ckin
g.
•
Ele
ctri
cal
com
po
nen
ts
may
ca
use
a
spar
k
that
can
lea
d t
o e
xp
losi
on
if
any l
eak
age
of
flam
mab
le c
hem
ical
occ
urs
.
•
Sta
inle
ss s
teel
is
reco
mm
end
ed f
or
pro
cess
str
eam
to
pre
ven
t co
rro
sio
n.
•
Th
e th
ick
nes
s o
f th
e eq
uip
men
t n
eed
to
b
e o
n-
spec
ific
atio
n.
•
Ele
ctri
cal
equ
ipm
ents
sh
ou
ld
be
spar
k
resi
stan
ce
to
avo
id i
nci
den
t an
d p
rop
erty
lo
ss.
•
Su
itab
le
mat
eria
ls
of
con
stru
ctio
n
incl
ud
e st
eel,
stai
nle
ss
stee
l,
and
al
um
inu
m.
Gal
van
ized
st
eel
and
pla
stic
s sh
ou
ld n
ot
be
use
d.
Tem
per
atu
re a
nd
Pre
ssu
re
•
Hig
h p
ress
ure
op
erat
ion
may
ca
use
ser
iou
s
leak
age
pro
ble
m.
•
Ap
pro
pri
ate
des
ign
, op
erat
ing,
and
max
imu
m p
ress
ure
and
tem
per
atu
re a
re n
eed
ed t
o e
nsu
re s
afe
pro
cess
es.
54
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
•
Po
ssib
le a
cces
s o
f ai
r lo
w p
ress
ure
op
erat
ion
,
wh
ich
may
cau
se f
lam
e o
r ex
plo
sio
n w
hen
reac
t w
ith
fla
mm
able
co
mp
on
ent.
•
Hig
h t
emp
erat
ure
can
lea
d t
o r
up
ture
of
tub
es
carr
yin
g
pro
cess
fl
uid
s an
d
po
ssib
le
exp
losi
on
s.
•
Pro
tect
ion
b
y
inst
rum
ent
is
imp
ort
ant
to
mai
nta
in
tem
per
atu
re
and
p
ress
ure
to
th
e n
orm
al
op
erat
ing
pre
ssu
re.
To
xic
olo
gy
and
H
ealt
h
Haz
ard
s
•
Mo
st
chem
ical
s in
th
e p
roce
ss
or
pro
du
ct
stre
ams
hav
e to
xic
ity a
mo
un
t if
in
ges
ted
or
inh
aled
.
•
Fre
qu
ent
exp
osu
re o
f th
e ch
emic
als
may
lea
d
to h
um
an m
uta
gen
ic.
•
Dir
ect
con
tact
m
ay
cau
se
corn
eal
inju
ries
,
sev
ere
eye
irri
tati
on
or
bu
rns
to t
he
eyes
.
•
Pro
per
PP
E s
ho
uld
be
use
d t
o a
vo
id a
ny d
irec
t co
nta
ct
and
in
hal
atio
n o
f th
e to
xic
ch
emic
al.
•
Pro
per
ch
emic
al
han
dli
ng
pro
ced
ure
w
ith
h
igh
sup
erv
isio
n f
rom
ex
per
t p
erso
nn
el i
s n
eed
ed t
o e
nsu
re
safe
pro
ced
ure
s o
f op
erat
ion
.
Fla
mm
abil
ity
•
Ex
plo
sio
n
may
o
ccu
r if
th
e ch
emic
als
in
reb
oil
er o
r h
eate
r ar
e o
ver
hea
ted
.
•
Sp
ark
ca
n
be
pro
du
ce
fro
m
too
ls
and
veh
icle
s d
uri
ng m
ain
ten
ance
op
erat
ion
.
•
Wh
en
flam
mab
le
chem
ical
le
aks
reac
h
elec
tric
al c
om
po
nen
ts,
exp
losi
on
may
occ
ur.
•
Pro
hib
ited
an
d e
lim
inat
e al
l sp
ark
s an
d i
gn
itio
n s
ou
rces
as
wel
l as
an
y
flam
e u
sag
e in
th
e p
lan
t ar
ea
(e.g
.
smo
kin
g).
•
Usa
ge
of
ho
t w
ork
per
mit
is
nee
ded
if
any f
lam
e o
r
spar
kin
g
equ
ipm
ent
is
bei
ng
use
d.
Lo
wer
ex
plo
siv
e
lim
it (
LE
L)
of
the
area
mu
st b
e at
saf
e le
vel
bef
ore
an
y
op
erat
ion
st
arts
, w
ith
su
per
vis
ion
w
hil
e it
is
in
55
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
pro
gre
ss.
En
vir
on
men
tal
Imp
act
•
Was
te w
ater
str
eam
fro
m t
he
pro
cess
pla
nt
can
be
haz
ard
ou
s if
no
t w
ell
trea
ted
bef
ore
bei
ng r
elea
sed
to
su
rro
un
din
g o
r ri
ver
.
•
Pro
per
was
te w
ater
tre
atm
ent
is n
eed
ed t
o r
edu
ce t
he
tox
icit
y o
f w
ater
an
d t
he
com
po
nen
ts r
elea
sed
.
Sit
tin
g a
nd
Saf
e L
oca
tio
n
•
Em
issi
on
of
tox
ic a
nd
haz
ard
ou
s ch
emic
als
into
th
e at
mo
sph
ere
can
af
fect
th
e p
lan
t
per
son
nel
an
d
the
com
mu
nit
y
of
nea
rest
resi
den
tial
are
as.
•
Hig
h
risk
o
f d
isas
ter
(e.g
. ea
rth
qu
ake,
flo
od
ing e
tc)
may
cau
se s
erio
us
pro
ble
m t
o
the
pla
nt
op
erat
ion
.
•
Co
nsi
der
saf
e li
vin
g c
on
dit
ion
s fo
r p
lan
t op
erat
ion a
s
wel
l as
th
e n
earb
y c
om
mu
nit
y.
•
Su
itab
le p
lan
t lo
cati
on
sh
ou
ld b
e fa
r fr
om
res
iden
tial
area
, w
ith
th
e av
aila
bil
ity o
f n
earb
y so
urc
es o
f ra
w
mat
eria
ls a
nd
oth
er f
acil
itie
s su
ch a
s tr
ansp
ort
atio
n a
nd
fire
sta
tio
n.
•
Pro
vid
e ac
cess
ibil
ity
for
fire
fi
gh
tin
g
in
case
o
f
emer
gen
cy i
nv
olv
ing f
lam
e an
d e
xp
losi
on
.
•
Pro
vid
e ad
equ
ate
loca
tio
ns
of
emer
gen
cy
exit
s fo
r
rap
id e
vac
uat
ion
an
d r
escu
e.
•
Lo
cate
in
-sit
u a
uto
mat
ic f
ire
det
ecti
on
an
d s
up
pre
ssio
n
syst
ems
com
po
nen
ts
for
effe
ctiv
e re
spo
nd
w
ith
min
imal
rel
ian
ce o
n p
lan
t p
erso
nn
el.
•
Eli
min
ate
ign
itio
n
sou
rces
fr
om
th
e v
icin
ity
of
the
mo
st
flam
mab
le
and
ex
plo
siv
e m
ater
ials
an
d
equ
ipm
ent.
56
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
•
Iso
late
th
e m
ost
haz
ard
ou
s m
ater
ials
an
d p
roce
sses
to
mai
nta
in s
pec
ial
pre
cau
tio
ns
in t
hes
e h
azar
do
us
area
s.
Th
e si
ze an
d ex
ten
t o
f an
y h
azar
do
us
area
m
ust
b
e
lim
ited
to e
nsu
re t
hat
the
pla
nt
is n
ot
at r
isk
fro
m a
ny
acci
den
t
•
Pro
vid
e p
assi
ve
bar
rier
s fo
r fi
re
con
tain
men
t an
d
exp
losi
on
re
sist
ance
, w
hic
h
sho
uld
ef
fect
ivel
y
lim
it
fire
or
exp
losi
on
pro
pag
atio
n a
nd
dam
age
even
in
the
abse
nce
of
acti
ve
det
ecti
on
an
d s
up
pre
ssio
n.
Pla
nt
Lay
ou
t •
Po
or
arra
ngem
ent
of
pro
cess
ing
area
s,
sto
rag
e ar
eas,
an
d
han
dli
ng
area
s fa
cili
ties
may
tro
ub
le t
he
pla
nt
op
erat
ion
, si
nce
mo
re
dam
age
and
acc
iden
ts w
ill
occ
ur.
•
Co
nsi
der
saf
e op
erat
ion
al s
equ
ence
in
th
e la
yo
ut
bas
ed
on
th
e fl
ow
of
mat
eria
ls,
un
it o
per
atio
ns,
sto
rage
and
futu
re e
xp
ansi
on
.
•
Sep
arat
e p
roce
ss
and
n
on
-pro
cess
ar
ea.
Fla
rin
g
and
sto
rag
e ar
ea s
ho
uld
be
loca
ted
far
fro
m p
roce
ss a
rea.
•
Ass
emb
ly
area
s m
ust
b
e p
rov
ided
in
ca
se
of
emer
gen
cy a
t b
oth
pro
cess
an
d n
on
-pro
cess
are
a.
•
Co
nsi
der
th
e p
lace
men
t o
f ra
w w
ater
tan
k n
ear
the
hig
h
po
ten
tial
of
flam
ing a
rea.
•
En
ou
gh
lig
hti
ng a
nd
co
lor
cod
ing f
or
reco
gn
itio
n o
f
haz
ard
ou
s an
d n
on
haz
ard
ou
s ar
eas.
57
Item
P
ote
nti
al
Ha
zard
s P
ote
nti
al
Mit
iga
tin
g M
ea
sure
s
Tra
nsp
ort
atio
n
•
Sp
illa
ge
of
tox
ic
chem
ical
s m
ay
cau
se
seri
ou
s in
juri
es w
hen
dir
ectl
y b
e in
co
nta
ct.
•
Vap
or
may
pas
s th
rou
gh
th
e co
nta
iner
’s c
ap
if i
t is
no
t p
rop
erly
sea
led
.
•
Wit
h i
mp
rop
er r
oad
syst
em,
the
occ
urr
ence
of
acci
den
ts i
s o
f h
igh
ris
k.
•
Em
plo
yee
s n
eed
to
w
ear
per
son
nel
p
rote
ctiv
e
equ
ipm
ent
for
pro
tect
ion
fr
om
to
xic
an
d
haz
ard
ou
s
chem
ical
s.
•
Co
nta
iner
s m
ust
be
seal
ed p
rop
erly
an
d c
lear
ly l
abel
ed
bef
ore
bei
ng t
ran
spo
rted
.
•
Pro
hib
it u
nau
tho
rize
d v
ehic
les
fro
m e
nte
rin
g p
roce
ss
area
.
•
Pip
ing
arra
ng
emen
ts
and
jo
inin
g
mu
st
be
pro
per
ly
des
ign
to
av
oid
lea
kag
e.
•
Pro
vis
ion
of
pro
per
ro
ad s
yst
em i
s v
ery n
eces
sary
.
Ta
ble
15
: S
afe
ty R
isk
an
d M
itig
ati
on
Mea
sure
s
3.3 Emergency Situation Procedure
Accidents could be happened regardless of time and place. There is a need to list the
emergency procedure guideline.
General Procedure
Some of the procedures that must be taken when the emergency situation happened in the
plant are :
i. Do not panic and stay alert.
ii. Assess the situation around your area.
iii. Wait for instructions from supervisor or shift manager.
Fire/Explosion/>atural Disaster
This procedure should be taken for fire , explosion or natural disaster are same.Basically ,the
procedures especially for the above situation are:
i. Raise the alarm.
ii. Immediately inform the supervisor or shift manager.
iii. Assess the situation.
iv. Wait and follow the instruction from them.
Hazardous Substance Discharge
If any hazardous substance discharge incident occurred, without taking any unnecessary
personal risk, the following procedure had to be followed:
i. Immediately inform the supervisor or shift manager
ii. Minimize substance discharge
iii. Identify substance and act accordingly
iv. Neutralize the substance discharge
v. Wait for the instructions from supervisor or shift manager
59
The following are the basic precaution for the two common hazardous substances:
1. Inflammable liquid
• Use only spark-proof materials
• Do not make any ignition
• Beware with electrical switchgear that can cause a spark.
2. Corrosive Liquid
• Use the safety clothes
• Check location and operation of safety shower or cold water supply
• Use breathing equipment if the substance emits toxic flames.
Instrument Protective System
Hazard not only comes from chemicals itself, it may come from the instrument use in the
process. Therefore there is a need to check the instrumentation protective system and should
be tested regularly to ensure it is in good condition. Some of the protective system is listed
below:
i. Air monitoring
ii. Leak detection system
iii. Emergency valves
iv. Labels and sign
v. Controlling leaks
3.4 Local Safety Regulations
Laws and regulations are major tools for protecting people and also environment
.Local safety and environmental regulations must be compiled with when developing new
plant, in order to ensure safe workplace and prevent accidents or any environmental pollution
that can adversely affect the whole plant operation as well as the surroundings. Listed are
several related acts and regulations for compliance:
60
Occupational Safety and Health Act (OSHA) 1994
OSHA was created with a purpose to reduce work-related injuries, illness and death and
incidentally, to cut resulting cost (lost wages and productivity, medical expenses, disability
compensation).
The following is the related act of OSHA for the process plant safety:-
• Factories and Machinery Act 1967
• Occupational Safety and Health (The Control of Industrial Major Accident
Hazards) Regulations 1996
• Occupational Safety and Health (Classification, Packaging, and Labeling of
Hazardous Chemicals) Regulations 1997
• Occupational Safety and Health (Use and Standards of Exposure of Chemicals
Hazardous to Health) Regulations 2000
Environmental Quality Act (EQA) 1974
Environment Quality Act 1974 has the objective for prevention, abatement and
control of pollution and enhancement of environment by restricting discharge of waste which
applies to the whole Malaysia. The act control pollution by licensing and approval for
existing operation, through prohibition of equipment and material, and Environmental Impact
Assessment (EIA) requirement.
61
Before starting any industry, EIA report has to be prepared to report the information
about the industry itself and the consequences to the environment, where it has to be
submitted to the Department of Environment of the state to be approved before license is
given. The following are the related act regarding to process plant industry:-
• Environmental Quality (Licensing) Regulations, 1977
• Environmental Quality (Clean Air) Regulations 1978
• Environmental Quality (Sewage and Industrial Effluents) Regulations 1979
• Environmental Quality (Prescribed Activities) Regulations 1986
• Environmental Quality (Prescribed Activities) (Environmental Impact
Assessment) Order 1987
• Environmental Quality (Scheduled Wastes) Regulations 1989
• Environmental Quality (Prescribed Premises) (Scheduled Treatment and
Disposal Facilities) Order 1989
• Environmental Quality (Prescribed Premises) (Scheduled Wastes Treatment
and Disposal Facilities) Regulations 1989
62
CHAPTER 4: CO�CEPTUAL DESIG� A�ALYSIS
4.1 Preliminary Reactor Optimization
4.1.1 Reactions Involved
There are three reaction paths involved in the process for the production of polyethylene
terephthalate (PET). The first path is esterification reaction, the second path is pre-
polycondensation reaction and the third path is final polycondensation reaction.
Esterification reaction:
C8H6O4 + 2 C2H6O2 ⇌ C12O6H14 + 2 H2O
Pre-polycondensation reaction:
nC12O6H14 ⇌ C2H5O(C10H8O4)nOH + (n-1)C2H6O2 n = 30
Final polycondensation reaction:
mC2H5O(C10H8O4)nOH ⇌ C2H5O(C10H8O4)n.mOH + (m-1)C2H6O2 m = 3.733
4.1.2 Esterification Reaction
In the esterification reaction, terephthalate acid (TPA), C8H6O4 is reacted with ethylene
glycol (EG), C2H6O2 producing monomer known as bis-(2-hydroxyethyl) terephthalate
(BHET), C12O6H14 and water, H2O. The reaction is reversible; therefore water formed during
the reaction has to be removed in order to convert the starting materials completely into the
monomer. A catalyst is not required in this reaction and conventionally no catalyst is
employed (Kathleen L. Trojan, 1999). Esterification is generally accepted as a third order
reaction, thus the acid behaves both as a reactant and a catalyst. The rate constant of
esterification was found to increase with pKa of the carboxylic acid (Faissal-Ali El-Toufaili,
2006).
63
Figure 10: Overall Esterification Reaction
The figure above describes the overall esterification reactions that occurred in the reactor.
Based on the figure, the limiting reactant is TPA and the excess reactant is EG. The amount
of EG that is use as feed in the process is 192.52 kmol/hr, however since the pre-
polycondensation and final polycondensation reaction produced EG as well, some of the EG
produced from the reactions will be recycle into the esterification reactor, making the
amount of feed into the first esterification reactor become 628.45 kmol/hr. The reaction
mixture in this reactor is a heterogeneous system in which solid, liquid and vapor phase are
jumbled together. Due to the solid TPA, a monomer in PET synthesis has very low solubility
in EG (Ju-Youl Kim, Hee-Young Kim & Yeong-Koo Yeo, 2001). A high operation
temperature of the esterification reactor is needed to dissolve the TPA in EG and to increase
the rate of reaction.
In the reaction system, it is assumed that the vapor pressure is contributed only by EG and
water because oligomer is not volatile, the vapor pressure of TPA and DEG are negligible,
and only EG vapor is recycled completely. All reactions proceed in liquid phase, and the
density of the reaction mixtures is assumed to be constant. Even though the reaction mixtures
are slurry with high viscosity, the assumption of perfect mixing is the reactor is applicable
since various mixing units are used in the actual plant to prevent loss due to imperfect mixing
(Ju-Youl Kim, Hee-Young Kim & Yeong-Koo Yeo, 2001).
ESTERIFICATION
REACTOR Mol flow rate (kmol/hr)
C8H6O4: 161.08
C2H6O2: 628.45
Mol flow rate (kmol/hr) C12O6H14: 158.02
H2O: 315.72
64
The reactor operates at 250ºC, at a pressure of about 265 kPa. Under these conditions and
with continuous removal of water by-product, it takes about 3 hours for the esterification
reaction to reach 85-95% conversion. The second esterification reactor operates at
temperature around 250ºC and at a pressure 250 kPa. The lower pressure reflects the fact that
in the second reactor, less volatile are being generated and the volatiles composition in
shifted from being rich in water to being rich in EG. After 2 hours, the esterification in the
second reactor is about 98% complete (S. M. Aharoni, 2002).
4.1.3 Polymerization Reactions
For the pre-polycondensation reaction, the BHET will further react to form the first polymer
of PET that has a degree of polymerization of 30 and EG. At this point, antimony trioxide is
added as catalyst. The reaction is also reversible; therefore the EG formed during the reaction
need to be removed to convert the monomer into the polymer. For the pre-polycondensation
reactor, the operating temperature is about 260ºC and the pressure is gradually decreased to
6.661 kPa where polyester with a degree of polymerization of around 30 is created. The pre-
polycondensation reactor is stirred tank reactors with unusual ratio of diameter or height to
provide large gas-liquid interface.
Figure 11: Pre-polycondensation Reaction
PRE-POLYCONDENSATION
REACTOR Mol flow rate (kmol/hr) C12O6H14: 158.02
Mol flow rate (kmol/hr) C2H5O(C10H8O4)30OH: 5.27
C2H6O2: 168.17
65
The final polycondensation reaction will proceed by expanding the polymer chain to produce
PET with a higher degree of polymerization, 112 (m x n = 112). This reaction is also
reversible and producing EG, therefore the EG formed need to be removed as well in order to
convert the reaction into the desired polymer. For this reactor, the operating condition is
280ºC with a pressure of 1.33 kPa. This reactor consist of horizontal vessels supplied by a
series of horizontal stirrers, which were optimized to provide a plug flow of the melt with
little back mixing in order to keep the residence time distribution narrow and to achieve
higher average polycondensation rate (Faissal-Ali El-Toufaili, 2006).
Figure 12: Final Polycondensation Reaction
Both of the reactors for polycondensation operate at a very high vacuum pressure to remove
the EG that is produced in the reaction. The final degree of polycondensation can be
controlled by adjusting vacuum, reaction temperature and average residence time.
Recycling of undesired product will increase the selectivity of the reaction. For example, in
the pre-polycondensation and polycondensation reactions, the EG that is produced can be
recycle into the esterification reactor and favor the reaction to produce more BHET. Another
advantage of recycling the by-product from polycondensation reaction is that the amount of
fresh feed (EG) that is needed to be feed into the reactor can be reduce and this will reduce
the cost of raw material.
Mol flow rate (kmol/hr) C2H5O(C10H8O4)112OH: 1.41
C2H6O2: 3.91
FINAL POLYCONDENSATION
REACTOR Mol flow rate (kmol/hr) C2H5O(C10H8O4)30OH:
5.27
66
4.2 Process Screening
4.2.1 Heuristic Approach for Separation System Synthesis
In conceptual design, other than the optimization of the reactor, separation sequence train is
also a major concern in designing a chemical processes.
i) Selection of separation techniques
ii) Sequencing of separation techniques
iii) Adapting operating conditions for integration and optimization
The objective of this separation train is to develop the overall flow sheet that indicates which
components need to be separated and where they are expected to leave the process. For this
process, two types of separators will be use depends on the inlet phase;
i) Distillation column – for single phase liquid mixture
ii) Two-Phase Separator – for two phase liquid-vapor mixture
4.2.2 Sequencing of Separators
For sequencing of separators in a separation system, the following heuristics were applied:
i) The most difficult separations will be done at the end of the process.
ii) Direct sequence is usually favored in this case. Sequences that remove the lightest
components alone one by one in column overheads should be favored.
iii) A component making up a large fraction of the feed should be removed first
Before entering the esterification reactor, the EG fed will be purify using distillation column
to remove the water content in the fresh feed. The same distillation column is use to purify
the EG recycled from the formation of by-product from polycondensation reactions.
Purification of EG fresh feed is important to overcome the accumulation of unwanted
impurities, in this case is water, which might affect the esterification reactions.
67
After entering the reactor, most of the products formed will be in two phase mixture. This
mixture can be separated by two-phase separator. The rules of thumb apply in heterogeneous
mixture separation:
i) Separation of heterogeneous mixture is easier than for homogeneous mixture
ii) Separation of heterogeneous mixture should be carried out before homogeneous
mixture separation
For this process, the use of separator is crucial especially in removing the water that has been
produced during the esterification reaction and removing EG in the polycondensation
reactions. This is to ensure that the reaction does not proceed to form the reactants since they
are reversible reactions. The vapor separated from the two-phase separator contains high
fraction of EG and water, thus both of this mixture need to be further separated using
distillation column. This vapor mixtures are cooled down to change the phase from vapor
phase to liquid phase in order to further separated using distillation column.
Besides using the distillation column for purifying of EG, it can also be used to separate
water from EG and at the same time, recycled back the EG into esterification reactor. The
advantages of using distillation column in separation of liquid mixtures:
i) Distillation columns offer the most economical way for liquid mixture separation,
as the operating cost is mainly on the utility (cooling water and steam) used within
the condenser and reboiler.
ii) Distillation are able to separate mixtures of wide range of liquid mixtures and
feed concentration, as other homogenous mixture separation are limited to feed
with low throughput and relatively pure.
iii) The ability of distillation to produce high-purity products, without involving any
extra components being introduced into the separation system like liquid-liquid
extractions.
68
4.2.3 Operating Conditions for Separators
The table below summarizes the operating conditions for separating unit in the process:
Unit Mixtures Operating Conditions
Distillation Column
Inlet = EG & Water
Outlet (liquid) = EG
Outlet (vapor) = Water
Reboiler
T = 207ºC P = 140 kPa
Condenser
T = 107.2ºC P = 130 kPa
Separator
(esterification)
Inlet = TPA, EG, Water & BHET
Outlet (liquid) = TPA, BHET, EG
Outlet (vapor) = Water & EG
Separator 1
T = 280ºC P = 141.7 kPa
Separator 2
T = 190º P = 131.7 kPa
Separator 3
T = 265ºC P = 101.3 kPa
Separator
(polycondensation)
Inlet = PET & EG
Outlet (liquid) = PET
Outlet (vapor) = EG
Separator 1
T = 280ºC P = 6.67 kPa
Separator 2
T = 270º P = 1.33 kPa
Table 16: Separators with Types of Mixtures and Operating Conditions
69
4.3 Economic Potential (EP)
4.3.1 Economy Analysis
It is crucial for plant designers and engineers to take economic feasibility into
consideration when planning a plant. Beside direct costs, there are also different types of cost
involved for the plant operation and establishment. The EPCIC (Engineering, Procurement,
Construction, Installation and Commissioning) has significant affect on plant economics.
Other factors that might affect economic are as shown below:
• Raw materials price fluctuation
• Company policies
• Governmental policies
Our economic analysis is based on assumptions stated below:
• The calculation made follows the Douglas’s approach method
• Prices for raw materials are valid till August 2010
• The interest rate for plant operation is 10% per annum
• Project life-cycle will be 20 years
• Plant operates at normal annual operation period which is 330 days
4.3.2 Total Capital Investment
Capital investment by is the total amount need to be invested in the early stages of
pant design.There are two parts for capital investment which are fixed capital investment and
working capital investment.
70
4.3.3 Fixed Capital Investment
Purchasing of necessary equipments plus the installation is crucial as it will be the
core investment that will determine the operatibility of the plant as well as piping installation,
land, instrumentation, services and the land where the plant is going to be established
Equipment Purchase Cost (RM)
Reactor 595,586.05
Separator 2,337,540.25
Compressor 535,223.00
Distillation column 7,032,410.00
Pump 801,888.17
Heater 1,266,312.00
Cooler 1,953,401.60
Mixer 2,421,233.00
Splitter 1,824,382.00
Total Equipment Cost 18,767,976.07
Source : MATCHES (www.matche.com)
Table 11 : Equipment Required and Estimated cost for PET Plant
71
From the fixed capital costs, we could split it into two costs which are direct cost and
indirect cost. The components of the direct and indirect cost are shown below:
COMPO�E�T ESTIMATIO� COST (RM)
Direct Cost
Total Equipments Costs 18,767,976.07
Equipment Installation (includes insulation and painting)
40% of total equipment cost 8,699,596.16
Piping System Installation 50% of total equipment cost 10,874,495.20
Instrumentation and Control 20% of total equipment cost 4,349,798.08
Electrical System Installation 15% of total equipment cost 3,262,348.56
Service facilities 50% of total equipment cost 10,874,495.20
Building, process and auxiliary
40% of total equipment cost 8,699,596.16
Land 6% of total equipment cost 1,304,939.42
Yard Improvement 12% of total equipment cost 2,609,878.85
Total 69,443,123.68
Indirect Costs
Engineering and supervision Construction expenses
10% of total direct cost
6,944,312.368
Legal expenses 10% of total direct cost 6,944,312.368
Contractors fee 5% of total direct cost 3,472,156.184
Contingencies 12% of total direct cost 8,333,17.842
Total 18194098.03
Fixed Capital Investment Direct Costs + Indirect Costs 87,637,221.71
Table 12 : Fixed Capital Investment for PET Production Plant
72
4.3.4 Working Capital Investment
Working capital represents costs necessary to operate the plant. Listed below are the
components of the working capital that need to be taken account.
1. Raw materials for one-month supply.
2. Finished products in stock and semi finished products.
3. Accounts receivable.
4. Cash on hand to meet the operating expenses.
5. Accounts payable and taxes payable
Typically, Douglas proposes that the estimated value of working capital investment is simply
15% of the fixed capital investment (III).
Working capital investment = 0.15 x fixed capital investment
= 0.15 x RM 87,637,221.71
= RM 13,145,583.26
4.3.5 Start Up Cost
Costs allocated for starting up the plant operation are start-up costs. Some of the examples of
start-up costs are process modifications, start-up labor and loss in production.
From Douglas method, the startup cost will be 10% out of fixed capital investment.
Start-up Costs = 0.10 x fixed capital investment
= 0.10 x RM 87,637,221.71
= RM 8,763,722.171
73
4.3.6 Total Capital Investment
The total for total capital investment is addition from fixed capital investment and working
capital. But we add up the start-up costs as added values.
Total capital investment = Fixed capital investment + Working capital investment
+ Start-up costs
= RM 87,637,221.71 + RM 13,145,583.26 + RM 8,763,722.171
= RM 97,715,527.14
4.3.7 Utilities
Plant uses both hot utility and cold utility. Both of the utilities tariff are take from
latest Tenaga Nasional Berhad as this industry falls under the category of industrial
consumer.
We assume that we will be using the high voltage industry tariff. Below shown the tariff for
high voltage industry:
Figure 9: Tariff for High Voltage Industries
74
UTILITIES USAGE TOTAL COST
Cold 2,065.6 kW/h RM549.45 /h (Peak period)
RM330.496 /h (Off-Peak Period)
Hot 3714 kW/h RM 965.64 /h (Peak period)
RM 594.24 /h (Off-peak period)
TOTAL RM 1515.09/h (Peak period)
RM 924.736 /h (Off- Peak period)
Table 13 : Plant Utilities
Assume Peak period 8AM-5PM
= RM1515.09 X 8 Hours
= RM12, 120.72
Off-Peak Period 7PM-8AM
= RM 924.736 X 16 Hours
= RM 14,795.776
Total for a day = RM 26,916.496
= RM 26916.496 X 330 days
= RM 8,882,443.68 /year
Economy Potential 1:
Economic Potential 1 (EP 1) = (Product value) – (Raw material cost)
Mass flow for main chemicals:
Ethylene Glycol (EG) = 11973.19 kg/hr
Terepthalic Acid (TPA) = 26760 kg/hr
PET = 30450.7 kg/hr
75
Pricing :
Substance Pricing (August 2010)
Ethylene Glycol $1006 / ton
Terepthalic Acid $895 / ton
PET $1 350 /ton
(Source: www.icis.com)
Calculations :
TPA =
= $718.39 /hr
EG =
= $ 2007/hr
PET =
= $34104.784/hr
Gross Profit
Profit = Product-Reactant
= $34104.784/hr – ($ 2007/hr + 718.39 /hr)
= $31379.394 /hr
= RM 97739.0804/hr
Gross Profit for a year (330 days)
76
Profit per day = RM97739.0804 /hr X 24 hours/Day
= RM 2,345,737.93/day
Profit per annum = RM 2,345,737.93/day X 330days/year
= RM 774,093,516.8 / year
77
4.4 Mass Balance by Manual Calculation & iCO� Simulation
Below is the mass balance performed by theoretical manual calculation compared to iCON
Simulation. Several assumptions have been made in order to have an accurate result.
a) Mass balance around esterification reactor 1 ( )
Manual
Component
Molecular
Weight
I�LET
OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
TPA 166.14 161.27 26793.39 8.06 1339.08
EG 62.08 628.45 39014.17 322.04 19992.24
BHET 254.26 0 0 153.21 38955.17
WATER 18.02 0 0 306.41 5521.50
Total
789.72 65808.01 789.72 65808.01
iCON
Component
Molecular
Weight
I�LET
OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
TPA 166.14 161.26 26790.78 8.06 1339.54
EG 62.08 628.59 39173.97 322.18 20156.39
BHET 254.26 0.33 53.66 153.53 39003.22
WATER 18.02 0.02 0.04 306.42 5520.28
Total
790.2 66018.45 790.2 66019.43
b) Mass balance around esterification reactor 2 ( )
78
Manual
Component
Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
TPA 166.14 8.06 1339.08 3.23 536.63
EG 62.08 322.04 19992.24 312.37 19391.93
BHET 254.26 153.21 38955.17 158.05 40185.79
WATER 18.02 0 0 9.67 174.25
Total
483.31 60286.51 483.31 60286.51
iCON
Component
Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
TPA 166.14 8.06 1339.08 3.23 536.63
EG 62.08 322.04 19992.24 312.37 19391.93
BHET 254.26 153.21 38955.17 158.05 40185.79
WATER 18.02 0 0 9.67 174.25
Total
483.31 60286.51 483.31 60288.61
c) Mass balance around pre-polycondensation reactor
( )
79
Manual
Component Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
BHET 254.26 158.05 40185.79 0 0
PET30 5824.46 0 0 5.268 30683.26
EG 62.08 0 0 152.78 9484.58
Total
158.05 40189.79 158.05 40167.83
iCON
Component Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
BHET 254.26 158.01 40176.72 0 0
PET30 5824.46 0 0 5.27 30690.95
EG 62.08 10.85 673.51 163.65 10159.41
Total
168.86 40850.21 168.92 40850.36
d) Mass balance around final polycondensation reactor
( )
Manual
Component Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
PET30 5824.46 5.268 30683.26 0 0
PET112 21575.02 0 0 1.411 30442.3
EG 62.08 0 0 3.857 239.55
Total
5.268 30683.26 5.268 30681.74
80
iCON
Component Molecular
Weight
I�LET OUTLET
mol
(kmol/hr)
mass
(kg/hr)
mol
(kmol/hr)
mass
(kg/hr)
PET30 5824.46 5.27 30690.91 0 0
PET112 21575.02 0.001 18.45 1.41 30450.71
EG 62.08 0.05 3.10 3.91 242.45
Total
5.321 30712.46 5.32 30712.66
a) Mass balance around distillation column ( )
Man
ual
Co
mp
on
ent
Mo
lecu
lar
Wei
gh
t
I�L
ET
O
UT
LE
T T
OP
(V
) O
UT
LE
TT
OP
(D
) O
UT
LE
T B
OT
TO
M
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
EG
6
2.0
8
62
8
38
98
6.2
4
0
0
0
0
62
8
38
98
6.2
4
WA
TE
R
18
.02
3
15
.71
5
68
9.0
9
31
5.7
1
56
89
.09
0
0
0
0
To
tal
9
43
.71
4
46
75
.33
3
15
.71
5
68
9.0
9
0
0
62
8
38
98
6.2
4
iCO
N
Co
mp
on
ent
Mo
lecu
lar
Wei
gh
t
I�L
ET
O
UT
LE
T T
OP
(V
) O
UT
LE
TT
OP
(D
) O
UT
LE
T B
OT
TO
M
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
mo
l
(km
ol/
hr)
ma
ss
(kg
/hr)
TP
A
16
6.1
4
0.1
9
31
.57
0
0
0
0
0
.19
3
1.5
7
EG
6
2.0
8
62
8.4
5
39
01
4.1
8
0
0
0.7
8
48
.42
6
28
.45
3
90
14
.18
BH
ET
2
54
.26
0
.33
8
3.9
1
0
0
0
0
0.3
3
83
.91
WA
TE
R
18
.02
3
00
.91
5
42
2.4
0
30
0.1
2
54
08
.16
0
0
0
.02
0
.36
04
To
tal
9
29
.88
4
45
52
.06
3
00
.12
5
40
8.1
6
0.7
8
48
.42
6
28
.99
3
91
30
.03
82
4
.4.1
Blo
ck D
iag
ram
fo
r P
rod
uct
ion
of
PE
T P
roce
ss
Fig
ure
13
: B
lock
Dia
gra
m o
f T
he
Pro
cess
CHAPTER 5 : HEAT I�TEGRATIO�
5.1 Pinch Analysis
Pinch analysis is a well establish synthesis and analysis tool for exchange of heat
within a network of heat exchangers. Some of its capabilities are:
i) Setting pre-design targets for utility consumption
ii) Setting pre-design target for the installed cost of heat exchanger network
iii) Designing heat exchanger network
iv) Optimizing the trade-off between energy costs and capital cost, optimizing the
selection of utility source
5.5.1 Pre-design Target for Utility Consumption
Problem Table Algorithm method is used to design heat cascade, composite curve and
grand composite curve. In problem table, the energy balance within the each segment of the
temperature interval connecting the hot and cold streams. The actual temperatures have to be
adjusted according to:
Cold stream = T + (∆Tmin/2)
Hot stream = T - (∆Tmin/2)
In this case, ∆Tmin = 10ºC. Below are the shifted temperature (TT*, TS*) for temperature
target (TT) and temperature supply (TS) together with the heat capacity.
Stream TT (ºC) TS (ºC) TT* (ºC) TS* (ºC) Cp (kJ/ºC.hr) H (kJ/hr)
H1 170 290 165 285 781.82 93818.4
H2 190 280 185 275 53959.49 4856354
C1 250 173.3 255 178.3 186103 14274100
C2 280 251.4 285 256.4 110576.9 3162499
C3 280 265 285 270 58248.9 873733.5 Table 17: Data from iCon Simulation
T
he
figu
re b
elo
w s
ho
ws
the
hea
t tr
ansf
er b
etw
een
eac
h i
nte
rval
of
tem
per
atu
re.
Th
e ex
pre
ssio
n t
hat
is
use
d t
o c
alcu
late
th
e h
eat
tran
sfer
bet
wee
n
each
in
terv
al i
s:
∑∑
∆−
=i
ico
ldp
ihot
Pi
TF
CF
CQ
])
()
([
,,
T(º
C)
∆T
(ºC
) Σ
Cp
c -
ΣC
ph
ot
∆H
(kJ
/hr)
D
efic
it/S
urp
lus
28
5
10
1
68
,04
3.9
8
16
80
44
0
Def
icit
27
5
5
11
40
84
.49
5
70
42
2.5
D
efic
it
27
0
13
.6
55
,83
5.5
9
75
93
64
D
efic
it
25
6.4
1.4
-5
4,7
41
.31
-7
66
37
.8
Su
rplu
s
25
5
70
1
31
,36
1.6
9
91
95
31
8
Def
icit
18
5
6.7
1
85
,32
1.1
8
12
41
65
2
Def
icit
17
8.3
1
3.3
-7
81
.82
-1
03
98
.2
Su
rplu
s
16
5
Fig
ure
14
: H
eat
Ba
lan
ce B
y M
an
ua
l C
alc
ula
tio
n
H2
85
P
erfo
rmin
g h
eat
casc
ade
of
surp
lus
hea
t fr
om
hig
h t
emp
erat
ure
in
terv
al t
o l
ow
tem
per
atu
re i
nte
rval
T (
ºC)
Qh =
13
37
05
58
.7
28
5
∆H
= 1
68
04
40
27
5
11
69
01
19
∆H
= 5
70
42
2.5
27
0
11
11
96
96
∆H
= 7
59
36
4
2
56
.4
10
36
03
32
∆H
= -
76
63
7.8
25
5
10
43
69
70
∆H
= 9
19
53
18
18
5
12
41
65
2
∆
H =
12
41
65
2
1
78
.3
0
∆
H =
-1
03
98
.2
1
65
Qc =
10
39
8.2
T (
ºC)
0
28
5
∆H
= 1
68
04
40
27
5
-16
80
44
0
∆
H =
57
04
22
.5
2
70
-22
50
86
2.5
∆H
= 7
59
36
4
2
56
.4
-30
10
22
6.5
∆H
= -
76
63
7.8
25
5
-29
33
58
8.7
∆H
= 9
19
53
18
18
5
-12
12
89
06
.7
∆
H =
12
41
65
2
1
78
.3
-13
37
05
58
.7
∆
H =
-1
03
98
.2
1
65
-13
36
01
60
.5
Fig
ure
15
: P
rob
lem
ta
ble
Alg
ori
thm
By
ma
nu
al
Ca
lcu
lati
on
Adju
st h
eat
casc
ade
fro
m
the
hig
hes
t n
egat
ive
val
ue
accu
mu
late
d
86
T
he
man
ual
cal
cula
tio
n w
as c
om
par
ed u
sin
g A
spen
HX
-Net
20
06
so
ftw
are.
QC =
24
85
kca
l/h
r
(1.0
4x
10
4 k
J/h
r)
Qh
=
3.1
96x
10
6
kca
l/hr
(1.3
37
x1
07 k
J/h
r)
87
C
om
po
site
cu
rve
gen
erat
ed b
y u
sin
g A
spen
HX
-Net
20
06
so
ftw
are
Fig
ure
16
: C
om
po
site
Cu
rve
gen
era
ted
by
usi
ng
Asp
en H
X-�
et 2
006
so
ftw
are
88
G
ran
d c
om
po
site
cu
rve
gen
erat
ed b
y u
sin
g A
spen
HX
-Net
20
06
so
ftw
are
Fig
ure
17
: G
ran
d C
om
po
site
Cu
rve
gen
era
ted
by
usi
ng
Asp
en H
X-�
et 2
00
6 s
oft
wa
re
89
H
eat
exch
anger
net
wo
rk g
ener
ated
by m
anu
al c
alcu
lati
on
To
tal
Ho
t U
tili
ty =
93
34
32
5.8
+ 3
16
24
99
+ 8
73
73
3.5
= 1
3,3
70
,55
8.3
kJ/
hr
To
tal
Co
ld U
tili
ty =
10
,39
8.2
06
kJ/
hr
∆H
(k
J/h
r)
T(º
C)
83
42
0.1
9
18
3.3
10
39
8.2
1
Cp
(k
J/h
r)
∆H
(k
J/h
r)
83
42
0.1
9
29
0
17
0
78
1.8
2
10
39
8.2
06
48
56
35
4
28
0
19
0
53
95
9.4
9
14
27
41
00
2
50
18
61
03
93
34
32
5.8
4
85
63
54
8
34
20
.19
31
62
49
9
28
0
25
1.4
4
11
05
76
.9
31
62
49
9
87
37
33
.5
28
0
26
5
58
24
8.9
87
37
33
.5
17
3.3
Fig
ure
18
: H
eat
Exch
an
ger
�et
wo
rk
17
4ºC
2
00
ºC
5.2 Difference in Heat Exchanger Duty Requirement Before and After Heat
Integration (HI)
i) Hot utility
Duty before HI = 18,310,332.5 kJ/hr
Duty after HI = 13,370,558.3kJ/hr
ii) Cold utility
Utility excluded in HI = 7,425,733.81 kJ/hr
Duty before HI = 7,425,733.81 + 4,950,172.4 = 12,375,906.21 kJ/hr
Duty after HI = 7,425,733.81 + 10,398.206 = 7,432,132.016 kJ/hr
Type of Utility Duty before HI
(kJ/hr) Duty after HI (kJ/hr) % Saving
Hot 18,310,332.5 13,370,558.3 26.98
Cold 4,950,172.4 10,398.206 39.95
Table 18 : Summary Of % Saving After Heat Integration
From the heat integration analysis table, the plant can reduce the amount of cold utility and
hot utility up to 29.95% and 26.98% respectively. Thus, it can be concluded that heat
integration in beneficial as it reduce the operating cost.
91
CHAPTER 6 : PROCESS DESCRIPTIO�
6.1 Process Description
Polyethylene Terephtalate (PET) is a type of thermoplastic polymer at which it is
produced by step-growth polycondensation polymerization under evolution of condensates
that is water during the esterification process and also ethylene glycol (EG) during the
polycondensation process.
Figure 19: Reaction flow of PET production.
92
6.2 Feed Raw Material
The first step in producing Polyethylene Terephtalate is the esterification process
whereby in this process, Terephthalic Acid (TPA) is reacted with Ethylene Glycol (EG) in a
direct esterification reaction, producing bis-(2-hydroxyethyl) terephthalate (BHET) and
water.
At the plant, the recycled Ethylene Glycol (EG) produced from the previous poly
condensation process are mixed with raw EG from supplier. Mixture of raw Ethylene Glycol
(EG) with the recycled one contained some impurities, thus they are fed to the distillation
column for the impurities to be removed first. Then purified Ethylene Glycol (EG) is fed to
another mixer to be mix with Terephtalate Acid (TPA) to form a paste at atm pressure and
room temperature. In the case of plant PET production, both raw reactants that is Ethylene
Glycol and Terephtalate Acid (TPA) are stored in two different storage facilities at which
Ethylene Glycol (EG) is stored in tank while Terephtalate Acid (TPA) is stored in the silos
since it is in powdered form compared to the Ethylene Glycol (EG) that initially is in liquid
form.
6.3 Reactions Involved
6.31 Esterification Process
As for the industrial production of PET, the ratio between feed Ethylene Glycol (EG)
to Terephtalate Acid (TPA) fed to the esterification reactor are in the range of 1.2:1 in order
to maximise the reaction between these two reactants since Terephtalate Acid (TPA) acts as
the limiting reactant in this reaction.
The mixtures of these two reactants are then being heated up to temperature of 250oC
and pressure of 265kPa in the first esterification reactor. The temperatures is further increased
in the second esterification reactor up to 265oC while the pressure is decreased to the atm
pressure since most of the water vapour formed from the eterification process has been
removed earlier in the first eserification reactor. This esterification reaction is reversible,
93
hence the water formed during the reaction has to be removed in order to convert the starting
materials completely into the monomer.
Figure 20 : Esterification process
Figure21: Series of esterification reactor
6.32 Separation Process
Water vapour that has been removed from the first reactor during the esterification
process is separated from the remaining unreacted Ethylene Glycol (EG) and Terephtalate
Acid (TPA) by using separator. The bottom product of this separator that mostly contains the
remaining Ethylene Glycol (EG) and Terephtalate Acid will further reacts to form BHET
monomer thus increase the total reaction conversion.
As shown in figure 6.3, for each of the rector, there is at least one separator to
separate the resulted water vapour produced from the esterification process. The top product
94
from these separators is fed to the Ehtylene Glycol (EG) recovery system at which Ethylene
Glycol (EG) will be recovered using distillation column.
There are two (2) flash tanks acted as separator attached to the output or the first
esterification reactor. These flash tanks operated to separate water vapour produced from the
esterification process from the mixtures. High input temperature to the flash tank causes
more water vapour to evaporates that induced some of the Ethylene Glycol (EG) to vaporize
as well. Thus the second flash tank meant to reduce the losses of Ethylene Glycol (EG) and to
increase degree of separation water vapour as well.
The bottom product of the second flash tank is then fed back to the second
esterification reactor. This at the same time could minimized the losses of Ethylene Glycol
(EG) from the system itself.
Figure 22: Ethylene Glycol recovery system
A distillation column involved in the Ethylene Glycol (EG) recovery system at which
all the recycled streams from top product of flash tanks connected with the reactor in the
esterification and polycondensation process are fed to the distillation column. These recycled
streams are cooled first by the cooler since most of the top product of the flash tanks are in
the form of gas phase thus by lowering the temperature, it could liquefied these gasses before
95
being fed into a mixer (M1) and then to the distillation column to separate between used
Ethylene Glycol and water vapour moisture.
The bottom product of this distillation column that contains minimum impurities mix
back with added raw Terepthalate Acid (TPA) for the continuous of PET process. The top
products of the distillation column that mostly contained water went to the water treatment
system for further treatment process before being released to nearby natural water system.
6.33 Purging system
Figure 23: Purging system
As for the purging system, it is crucial to have it as small amount from the
combination of two (2) streams that is the recycled system and raw input of Ethylene Glycol
(EG) will be purged into the Ethylene Glycol (EG) Recovery tank. The main reason for the
plant to have this purging system is to avoid any over accumulated of Ethylene Glycol (EG)
in the recycled stream that later will disturb the ratio of Ethylene Glycol (EG) to Terephtalate
Acid (TPA) used as feeds in the overall process.
96
6.34 Polycondensation Process
Previously, Ethylene Glycol (EG) and Terapthalate Acid (TPA) did not fully react in
the esterification process thus some acid end-groups from Terepthalate Acid (TPA) remain in
the prepolymer further react to form oligomer of PET.
These oligomers of PET and bis-(2-hydroxyethyl) terephthalate (BHET) will proceeds
to the next reactor to form PET with desired degree of polymerization (DP) in the
polycondensation process.
Unlike esterification process, polycondesation process of BHET to produce PET
requires the addition of catalyst to induce the rate of reaction in the step-growth
polycondensation. The catalyst most frequently employed in the polycondensation reaction is
a catalyst based on antimony such as antimony acetate or antimony trioxide.
The product (BHET) from this esterification process will acts as the monomer to
undergo to the next polycondensation process to form the PET. Monomer BHET is lead to
step-growth polymerization in the form of melt phase to polycondensation reactor. For the
purpose of polycondensation process, two(2) reactors are used to produced PET with desired
degree of polymerization (DP). In the first reactor, monomer react at high temperature of
280oC and vacuum pressure of 6 kPa to induce the removal of Ethylene Glycol (EG) formed
during the polycondensation process.
As for the second reactor (high polymerizer) the short polymer chains formed in the
previous reactor lengthened. In this second reactor , temperature is maintained while the
pressure is further reduced to 1.3kPa at vacuum condition to forced more Ethylene Glycol
(EG) removed out from the mixtures in the bubble forms since the mixtures are now become
more viscous.
97
Figure 24: Series of Polycondensation process.
The polycondensation processes proceeds until the desired PET product with certain
degree of polycondensation (DP) are produced. This degree of polymerization (DP) of the
final product of PET in the form of resins determines its physical and chemical properties at
which it signify the suitability of that resins to be used in the production of various grades
and types of products. As for the production of PET bottles, one need to produce degree of
polycondensation of PET resins between the ranges of 112-125.
Throughout the reactions of both esterification and polycondensation process, there
were some side reactions that occurred and produced some by-products together along with
the main products. During the evaporation of condensed byproducts, EG and W, is also
promoted by lower vacuum pressures, 6.666kPa in the first polycondensation reactor section
and 1.333 kPa in the second polycondensation reactor section, in order to favor the
lengthening of polymer chains. To overcome the high polymer viscosity, a high power to the
agitator of propeler and a high temperature, are required, but if the temperature is too high, i
leads to an undesired degradation due to side reactions, especially through the formation of
Aceteldehyde and Diethylene glycol (DEG) Then the product resulted from this second
polycondensation reactor should be in the form of viscous fluid with degree of
polymerization of n=112 that is required by bottle grade-PET.
Finally this polymer melt is generally filtered and then extruded into pellets.It is
extruded shortly after exiting the polycondensation stage and typically is extruded
immediately after exiting the polycondensation stage. Once the PET polyester is extruded it is
quenched, preferably in a water trough, to quickly decrease its temperature thus solidifying it.
98
The solidified PET polyester is formed into pellets or cut into chips for storage and handling
purposes
As for the formation of by-products during both of the process esterification and
polycondensation such as Aceteldehyde, it is resulted from degradation of BHET as the cause
of too high temperature in both of the process:
� +
BHET TPA Aceteldehyde
While for the formation of Diethylene Glycol (DEG), it is aby-products resulted from
reaction of BHET with unreacted Ethylene Glycol (EG) in the reactor.
+ OHCH2CH2OH � +
BHET EG TPA DEG
Other formation s of byproducts from the resulted side reactions are summarized as shown in
the figure below.
Figure 25: Reactions of functional group in stages of PET formation
99
CHAPTER 7 : CO�CLUSIO�S
Since the demand of Polyethylene Terephtalate (PET) is increasing throughout the
year, the production of PET through esterification and polycondensation process is viable and
economical as well. We could see that the rate of increasing for Polyethylene Tereplhtalate
demands is at constant and promising level each year thus provides a strong basis for one to
build a new plant producing this PET. This could be seen from the evaluation of Economic
Potential 1 (EP1) and Economic Potential 2 (EP2) that shown a high profit value since the
price of PET products is quite high as the reason of high demands from the consumers. Since
products made from Polyethylene Terephtalate is recyclable, it also could minimize the
emiisions of hazardous chemicals to the environments and at the same time could reduce the
consumption of oil petroleum products as well.
The main objective of this study that is to produced a flowsheet with a proper material
balance for a plant to produced Polyethylene Terephtalate (PET) in an industrial-scale
amount with all related preliminary crucial information to build a plant is achieved. This
includes the consideration of health, safety and environment (HSE) in the construction of the
plant so that its production is not only profitable but environment friendly as well. All
techniques and software related to construct the material and energy balance of the process
for producing this PET are stated in the report and each of the comparision values of
manually calculated and saftware calculated are at satisfied level since the error are at a low
value that not exceeded 0.05% as what has been practised by normal industrial practicioners.
All aspects of completing this project were partially completed and thus it is
preferrable for us to complete this project into the next semester.
100
REFERE�CES
• Hassan Niaz et. al, January 2009, PROCESS PLAN OF CONTINUOUS MELT-
PHASE POLYETHYLENE TEREPHTHALATE (PET) PRODUCTION PLANT
• S.M Aharoni, Industrial-Scale Production of Polysters, especially Polyethylene
Terephtalate (PET)
• Kevin C. Seavey, Step-Growth Polymerization Process Modelling and Product
Design
• Joonho Shin1,a, Yunghyo Leeb, Sunwon Park, 1999, Optimization of the pre-
polymerization step of polyethylene terephthalate (PET)
• Flavio Manenti, 2008, Integrated Multilevel Optimization in Large-Scale
Poly(Ethylene Terephthalate) Plants
• Yunqian Ma, 2005, Post Polymerization of Polyester for Fiber Formation
• Organic Chemical Process Industry
• JOHN SCHEIRS, 2003, Modern Polyesters: Chemistry and Technology of Polyesters
and Copolyesters
• Fatemeh Ahmadnian, 2008, Kinetic and Catalytic Studies of Polyethylene
Terephthalate Synthesis
• Robert H. Perry & Don W. Green, “Perry’s Chemical Engineering Handbook”, 7th
Edition, Volume 2, Mc-Graw Hill International Edition
• Pattalachinti, R.K., Modeling and Optimization of Continuous Melt-Phase
Polyethylene Terephthalate Process. Ohio University Master's Thesis, 1994
101
• Timothy J. Calmeyn, Optimization of Melt-Phase Polyethylene Terephthalate
Manufacturing Process. Ohio University Master's Thesis, 1995
• Faissal-Ali El-Toufaili, Catalytic and Mechanistic Studies of Polyethylene
Terephthalate Synthesis.Project Report, 2006
102