338413072 cpb30004-process-dynamics-and-control-mini-project-production-of-acetic-acid

C P B 3 0 0 0 4 - P r o c e s s D y n a m i c s a n d C o n t r o l
M i n i P r o j e c t - F u l l R e p o r t ( P r o g r e s s R e p o r t 3 ) P a g e | 1
Malaysian Institute of Chemical and Bioengineering Technology
PROCESS DYNAMICS & CONTROL
CPB 30004
MINI PROJECT
PRODUCTION OF ACETIC ACID
Lecture’s Name: Zulhafiz
Group Lecture: LO1-T02
Student’s Name ID Number
Syed Amirul Shahab b. Syed M.Fikry 55213115457
Siti Hajar Mohamed 55213114225
Nabilah binti Nordin 55213114016
Anis Izzati binti Mohd Kelana 55213114022
TABLE OF CONTENT

Contents Pages
Front Page……………………………………………………………………………i
Table of Content…………………………………………………………………….ii
Chapter 1: Executive Summary……………………………………………………..1
Chapter 2: Introduction………………………………………………………………2
2.0 Project Description………………………………………………………2
2.1 Properties and Uses……………………………………………………..3
Chapter 3: Progress Report 1……………………………………………………….6
3.0 Overview…………………………………………………………………6
3.1 Control Objectives……………………………………………………….6
Chapter 4: Progress Report 2……………………………………………………
4.0 Overview
4.1 PID Diagram
4.2 Process Description (with process measurement and feedback control)
Chapter 5: Progress Report 3……………………………………………………
5.0 Overview
5.1 Control Strategies
References………………………………………………………………………

CHAPTER 1
EXECUTIVE SUMMARY
Production of acetic acid is one of the major demanding in the worldwide. To produce
acetic acid several factors need to be consider during the selection of the process such as demand
of the acetic acid, the cost, the quality of acetic acid, and safety consideration. The target
production annually is about 400 000 tonnes (MT) per year of acetic acid.
There are basically several process to produce acetic acid. After considering the factors
and other consideration, the selected process is methanol carbonylation. The methanol
carbonylation uses methanol to produce acetic acid. Thus, the raw material in this process is
methanol and carbon dioxide. The cost for the both raw material; methanol and carbon dioxide
are RM 2677.06/metric ton and RM 2779.15/metric ton respectively.
Acetic acid is widely used in the world. Basically, acetic acid is used as a solvent to many
industrial process especially producing acetate ester. However, the most common uses of acetic
acid is vinegar where acetic acid is being diluted. In medical treatment, acetic acid is used for
testing blood in clinical laboratory and also as the pharmaceuticals preparation for preparing
aspirin that form by salicylic acid with acetic acid. Besides, the acetic acid could be applied for
outer ear infections treatment from the growth of fungus and bacteria.
In conclusion, there are many application that required acetic acid. Acetic acid which is
also known as ethanoic acid is a chemical organic compound as it consist of hydrogen, carbon
and oxygen with the chemical formula CH3COOH. It is an acetic acid with colourless, pungent
smell and sour with the acidity pH is 4.8 in 25°C. Generally, Europe is the main pioneer in
demands of acetic acid with the top three country are Belgium, Germany and Netherlands. The
second demanding continent is Asia; India, Thailand and Malaysia. The third in place falls to the
North America followed by South America, Africa and last continent is Oceania ($4.86M).
Rough estimation annual profit for 400 000 tonnes per annum profit per year for raw materials
cost and production of acetic acid is RM 1 524 060 958.77.

CHAPTER 2
INTRODUCTION
2.1 Project Describtion
It is believed that acetic acid was first found by Jabir Ibn Hayyan a muslim chemist in the
8th
century where he was the first person concentrating acetic acid from vinegar through
distillation process. Acetic acid was first synthesized from inorganic material by Herman Kolbe a
Germany chemist in 1874 using chlorination of carbon disulfide. However, acetic acid was
isolated by distillation of wood; where glacial acid come from “pyroligneous liquor” in 1910.
Acetic acid is widely used in industry where it is also known as ethanoic acid (common
name). Acetic acid contains 2 carbons, 4 hydrogens and 2 oxygen with double bond and the
molecular formula CH3COOH. In chemistry, acetic acid is one of carboxylic acid and it is the
second simplest among that group. It is classified as weak acid where the pH is only 2.4.
Basically, this acid is in liquid phase and becoming essential chemical reagent in
industrial chemical that useful for various production such as for food and synthetic fibers.
According to Noriyiki Yoneda (2001), acetic acid can be produced both synthetically and by
bacterial fermentation. Biologically, only about 10 percent of world produce an acetic acid, but it
remains important for vinegar production, as many of the world food purity laws demand that
vinegar used in foods must be of biological origin. Even though this chemical can be produced in
many ways however the process being chosen is methanol carbonylation process because of its
characteristics and demand in the world.
2.2 Properties And Uses
Table 2.1: Physical and chemical properties of acetic acid
Molecular formula CH3COOH
Molecular weight 60.05 g/mol

Appearance Colourless or crystal
Smell Pungent smell
Taste Sour
Phase Solid, liquid
Density 1.049g/cm3
,liquid
1.266 g/cm3
, solid
Solubility Soluble in water
Boiling Point 118.1°C
Melting Point 16.5 °C
Flash Point 43°C
Viscosity 1.22 mPa·s at 25°C
Acidity (pKa) 4.8 at 25°C
Enthalpy formation ΔfH(l)= −483.5 kJ/mol
Vapour pressure 1.5 kPa at 20 °C
Based on National Institute for Occupational Safety and Health (NIOSH), acetic acid is
flammable and could be explosive at 39°C. It is also corrosive to metal and tissue.
It is known that acetic acid is widely used in this world. Commonly, this acid being used
as a solvent to many industrial process especially producing acetate ester. However for the very
basic use, acetic acid is diluted to be a vinegar where there is 4-8% acetic acid in vinegar which
is used as food additive to enhance the taste. In electrical sector, acetic acid is being used as
cleaning agent for instance it can be used for acid metal cleaner as oxide remover.
Next, acetic acid is used for testing blood in clinical laboratory and also as the
pharmaceuticals preparation for preparing aspirin that form by salicylic acid with acetic acid.
Besides, in medical used this acid could be applied for outer ear infections treatment from the
growth of fungus and bacteria.
In polymer industry, acetic acid is a basic acid that being used. Acetic acid will react with
cellulose that could be find in cotton or wood would produce cellulose acetate which it can make
textiles and films. Moreover, another ester of acetic acid that used for polymerization is vinyl

acetate where it can form polyvinyl acetate that always being used in latex paints and paper or
wood glues.
Lastly, it is also being applied in educational for example to understand the preparation of
buffer solution or pH where basic chemistry study for high school and university students in
Malaysia.
Acetic acid actually colorless liquid that has smell like pungent and taste like vinegar.
There are so many used of acetic acid in making product. It just like ink for textile printing, dyes
and photographic. The acidic corrosive is the principle segment of vinegar yet at low fixations
that are innocuous to people. Acidic corrosive can go through the earth from release and
emanations from ventures. The smoldering of plastics or elastic, and fumes vapor from vehicles
may likewise discharge acidic corrosive into nature. At the point when discharged into soil it
dissipates into the air where it is separated actually by daylight.
These chemicals are the main part of the liquid vinegar and harmless because its
concentration is very low. It can also be piped into rivers or drainage related to the environment
if not required by the industries. Besides, acetic acid can be generated through the burning of
rubber, plastic and smoke from vehicles. Acetic acid will also break down by sunlight naturally
when the shed to the ground.
Thus, the environmental consequences are not to be dangerous to public. Breathing steam
with more quantity and also high concentration of acetic acid can cause irritation to the eyes and
nose, headache and confusion and are likely to experience health problems as a result of the high
exposure of acetic acid while at workplace. Drink with a large number of acetic acid which can
cause mouth and throat come injured by burn, abdominal pain and diarrhea.
Spill high concentrations on the skin can cause burns and exposure to the eye may cause
pain, tears and increased sensitivity to light. Children exposed to more concentrate of acetic acid
are expected to show same effects on the adults and even children are easy to get the impression
again and again quickly.
There are few data on the effect of acetic acid on the baby child during pregnancy,
although no effect on the child or developing fetus have been reported. It also can cause loss of
contents. No data either acetic acid to cause cancer in humans.
Acetic acid technology is probably the most diverse in all major industrial organic
chemicals because it is easily handled and not too dangerous for the environment and the
environment. No other provided the total chemical that can claim a range of feed stocks and
production of acetic acid approach. Additionally, methanol carbonylation was acetic acid of

production technology is dominant, then global capacity demand is accounting for over 65% and
might be increase.
The main production process for acetic acid is basically ethanol will have an aerobic
fermentation to produce that acetic acid. Ethanol is from catalytically dehydrogenated and
oxidized to acetaldehyde, which is further oxidized to acetic acid. There are some types of
production process that founded. Below are the list of the production process:
 Methanol carbonylation
 Liquid phase oxidation of butane
 Oxidation of acetaldehyde
 Manufacturing acetic acid by partial oxidation of ethane
 Manufacturing acetic acid by oxidation of naphtha
 Manufacturing acetic acid by fermentation of hydrocarbons
 Acetic acid produces as by product from polyvinyl alcohol and cellulose acetate
manufacturing
CHAPTER 3
PROGRESS REPORT 1
3.0 Overview
In this chapter, the five control objectives in terms of production specifications,
economical regulations, safety, operational constraint and economy are determined and related
with the production of acetic acid.
3.1 Control Objectives
3.1.1 Production Specifications
Production of acetic acid used rhodium as the catalyst of this process and is operates at a
pressure of 30 to 60 atm and temperature range between 150 to 200 o
C. Selectivity of the process
is over 99% by using methanol as the raw material.

Methyl iodide formed via the reaction of methanol and hydrogen iodide during the process of
methanol carbonylation. Major rhodium catalyst species present is [Rh(CO)2I2]-
. Methyl Iodide
adds oxidatively to rhodium species to form rhodium-methyl complex. This rhodium-methyl
complex will undergo rapid change which methyl will be shifted to neighboring carbonyl group
and after subsequent addition of CO, the rhodium complex will be locked into acyl form.
Reductive elimination of acyl species and reaction with water then can occur to liberate the
original rhodium dicarbonyl diiodide complex to form acetic acid and hydrogen iodide, HI.
When the water content is high (>8 wt.%) the rate determining step in process is the oxidative
addition of methyl iodide to the rhodium center. However, if the water content is (<8 wt.%) the
rate determine the step becomes the reductive elimination of acyl species.
Side reaction represent a loss of selectivity respect to the CO raw material. The gaseous by-
product dilute CO present in the reactor, thus lowered the partial pressure. Propionic Acid is the
major liquid by-product that form from the carbonylation of ethanol which is present as impurity
in methanol feed.
The carbonylation process is carried out in the stirred tank reactor on continuous basis. Liquid
removed from the reactor through pressure reduction valve which then enter the flash tank where
methyl acetate, methyl iodide, water and acetic acid removed at top of vessel in vapor form.
High water concentration in excess of 10 wt.% are desire to prevent catalyst precipitation and
achieve high reaction rates.
3.1.2 Environmetal Regulations
i. Environmental effects

Environmental effects depend on the concentration and duration of exposure to acetic acid. In
high concentrations it can be harmful. When entering the environment, acetic acid can be
transferred as a vapor and is soluble in water and degrades rapidly to harmless substances in the
environment. Concentrated acetic acid is corrosive and attacks many metals forming flammable
or explosive gases. It can also attack some forms of plastic, rubber and coatings. It is a corrosive
substance.
ii. Effluents from a plant – within the limits
The allowable amount of acetic acid concentration in the effluent should be based on specific
site flow conditions, as approved by (EPA, 2007). The maximum acetic acid discharge limit in
the effluent is at 1 ppm. According to the Protection of Sensitive Aquatic Organisms, green algae
is one of the most sensitive aquatic organisms to acetic acid, with dose at 50% of the population
test (0.18 mg/L) and a no observable effects concentration of 0.12 mg/L, based on laboratory
test. To be consistent with the US EPA risk assessment policy for acute exposure, a target risk
quotient (or margin of safety) of 2 is needed. Thus, the target acetic acid concentration of 0.09
ppm was calculated to protect the most sensitive organisms in the receiving water body. This
value, coupled with the dilution factor based on the receiving flow, determines the target residual
acetic acid concentrations at the outflow.
Percentile Dilution Factor
Acetic acid Effluent Discharge
Limit (ppm)
Minimum
5th
10th
15th
20th
25th
30th
40th
12 1.06
50th
25 2.26

Limits Resulting in a Concentration of 0.09 ppm PAA in the Receiving Water Body. *Per the VigorOx WW
60th
55 4.94
70th
125 11.3
75th
204 18.4
80th
347 31.2
90th
1592 143
95th
6440 580
1 VigorOx WWTII – Wastewater Disinfection Technology
Table 1 indicates that fifty percent of the publicly owned treatment works (POTW) within the
US, the allowable acetic acid residual at the outfall in excess is 2.3 mg/L or higher. The study
demonstrated by the discharged of acetic acid into the receiving water body dissipates within
relatively short distances, within tens of meters downstream of the discharge point in all cases.
Thus, due to decomposition and dilution of acetic acid concentrations drop steeply once entering
the receiving stream. In conclusion, setting a site-specific, dilution-factor-weighted acetic acid
residual balances the protection of the most sensitive aquatic species with the ability to meet
target microbial pathogen reduction. In addition, the rapid decomposition of acetic acid leads to a
lack of persistence in the environment, influenced by the acetic acid formation with non-harmful
byproducts (acetic acid and water), suggests that a set limit of 1 ppm as a residual concentration
is not appropriate for all wastewater treatment plant effluents. Many wastewater treatment plants
across the US may discharge acetic acid in concentrations above 1 ppm and still maintain low
environmental impact on aquatic life.
3.1.3 Safety
Acetic acid which also known as ethanoic acid, is a colorless liquid organic compound with
the chemical formula CH3COOH) and when undiluted, it is called glacial acetic acid. Acetic acid

has a distinctive sour taste and pungent smell. Although it is classified as a weak acid,
concentrated acetic acid is corrosive and can attack the skin. In term of safety, it is including for
the equipment and personnel.
In term of personnel:
1. Safety handling of Acetic Acid
When handling acetic acid, never add water to this chemical and always keep acetic acid
away from sources of heat, sparks or flame. Suitable respiratory equipment must be wear
if handling acetic acid in an area that isn’t well-ventilated. It is recommended to use
gloves, splash goggles, synthetic apron and vapor respirator (if needed) (MSDSonline,
2014).
1. Proper Health Care for Acetic Acid Exposure
Exposure to acetic acid can pose serious hazards to health. This chemical is dangerous
when it comes in contact with either the skin or eyes. In any instance of acetic acid
exposure, it is important to seek help from a medical professional right away to help
prevent damaging health effects. As example, if contact with skin, immediately flush skin
with water for at least 15 minutes and remove contaminated clothing. Cover the irritated
skin with an emollient. In case of serious skin contact, wash using a disinfectant soap.
Seek out medical attention as soon as possible. Next, when contact with eyes, remove
contact lenses right away if present. Immediately flush eyes with plenty of water for no
less than 15 minutes. Seek medical attention immediately. If acetic acid is ingested, do
not induce vomiting. If victim is unconscious, do not administer any mouth-to-mouth
resuscitation. Loosen any tight clothing. Seek medical attention immediately if any
symptoms appear. Lastly, if inhaled, seek fresh air and medical attention immediately. If
breathing is difficult, administer oxygen. If breathing is absent, give artificial respiration
(NIOSH, n.d).

In term of equipment:
1. Safety handling with reactor
Install and operate the equipment within suitable barricade, if required, using
appropriate safety accessories and operating in full compliance with local safety
codes and rules. The requirements for barricades differ so widely that each should be
designed and built in order to protect against the potential hazards inherent in each
installation. Although this problem can arise when heating any fluid, it is particularly
dangerous when working with water for acetic acid. At temperatures up to 200 0
C, it
is passing the boiling point of acetic acid, hence the barrier chosen; concrete, brick or
steel, must bear the heat to avoid explosion in reactor (PARR, n.d).
2. Maximum Pressure and Temperature
The maximum pressure and temperature at which any reactor or pressure vessel
can be used will depend upon the design of the vessel and the materials used in its
construction. Since all materials lose strength at elevated temperatures, any pressure
rating must be stated in terms of the temperature at which it applies. As example,
acetic acid auto-ignition temperature at 427°C while flash point: 39°C. In addition,
the boiling point is 118 0
C and vapor pressure, kPa at 20°C is 1.5. Hence, titanium is
an excellent material for use with oxidizing agents such as nitric acid, aqua regia and
other mixed acids. Reducing acids, such as sulfuric and hydrochloric, which have
unacceptably high corrosion rates in pure titanium can have their corrosion rates
reduced to acceptable levels if relatively small quantities of oxidizing ions, such as
cupric, ferric, nickel or even nitric acid are present to act as corrosion inhibitors. It is
necessary to determine what type of materials construction that personnel should use
towards certain equipment so that when it is reaching the maximum pressure and
temperature limit, no harmful accidents might happen. This precautions step is to
assure the safety of personnel and equipment itself (NIOSH, n.d).

3.1.4 Operational Constraints
Based on National Institute for Occupational Safety and Health (NIOSH), acetic acid I, has
pungent smell, sour taste and can be in liquid or phase and soluble in water while it is also
flammable and could be explosive at 39°C. It is also corrosive to metal and tissue.
It is known that acetic acid is widely used in this world. Commonly, this acid being used as a
solvent to many industrial process especially producing acetate ester. However, for the very basic
use, acetic acid is diluted to be a vinegar where there is 4-8% acetic acid in vinegar which is used
as food additive to enhance the taste. In electrical sector, acetic acid is being used as cleaning
agent for instance it can be used for acid metal cleaner as oxide remover.
Next, acetic acid is used for testing blood in clinical laboratory and also as the
pharmaceuticals preparation for preparing aspirin that form by salicylic acid with acetic acid.
Besides, in medical used this acid could be applied for outer ear infections treatment from the
growth of fungus and bacteria.
In polymer industry, acetic acid is a basic acid that being used. Acetic acid will react with
cellulose that could be find in cotton or wood would produce cellulose acetate which it can make
textiles and films. Moreover, another ester of acetic acid that used for polymerization is vinyl
acetate where it can form polyvinyl acetate that always being used in latex paints and paper or
wood glues.
Lastly, it is also being applied in educational for example to understand the preparation of
buffer solution or pH where basic chemistry study for high school and university students in
Malaysia.
Acetic acid actually colorless liquid that has smell like pungent and taste like vinegar. There
are so many used of acetic acid in making product. It just like ink for textile printing, dyes and
photographic. The acidic corrosive is the principle segment of vinegar yet at low fixations that
are innocuous to people. Acidic corrosive can go through the earth from release and emanations
from ventures. The smoldering of plastics or elastic, and fumes vapor from vehicles may
likewise discharge acidic corrosive into nature. At the point when discharged into soil it
dissipates into the air where it is separated actually by daylight.

These chemicals are the main part of the liquid vinegar and harmless because its
concentration is very low. It can also be piped into rivers or drainage related to the environment
if not required by the industries. Besides, acetic acid can be generated through the burning of
rubber, plastic and smoke from vehicles. Acetic acid will also break down by sunlight naturally
when the shed to the ground.
Basically, methanol carbonylation is one of the process which undergo several upgradations.
Firstly, is the Mosanto process which begin when Mosanto Company introduced the rhodium or
iodine catalyst system for this process in 1970. This process generally operates at lower pressure;
30 to 60 atmospheres and temperature; 150°C to 200°C with the output of acetic acid is
approximately around 300 million pounds per year (Roth, 1975). Jones, (2000) stated that BP
Chemicals found a new technology for methanol carbonylation and claimed it have lower
production costs in 1996. The new found process is then called Cativa process which uses an
iridium as catalyst. The iridium catalyst basically produces 1.2 million tonnes per year and has
higher activity compared with the rhodium process. Generally, iridium catalyst can produce
lesser by product than rhodium catalyst. Chiyoda and UOP have improved the methanol
carbonylation process; known as Acetica process. This process uses heterogenous Rh catalyst to
produce acetic acid with simplifies high pressure operation and enables use of low purity CO.
The yields are approximately greater than 99% (Lim, 1999). Below is the overall stoichiometry
methanol carbonylation process.
CH3OH + CO → CH3COOH
Every equipment have constraints which is limit. In this plant operation, we have the
equipment such as reactor and feed tank.
3.1.4.1 Reactor
A major limitation in the reactor of the standard Iridium-catalyzed methanol carbonylation
technology is the instability of the catalyst in the CO-deficient areas of the plant, especially in
the flash tank. Conditions in the reactor have to be maintained within certain limits to prevent
precipitation of the catalyst. This imposes limits on the water, methyl acetate, methyl iodide and
Iridium concentrations. A minimum CO partial pressure is also required. To prevent catalyst

precipitation and achieve high reaction rates, lugh water concentrations in excess of 10 wt.% are
desirable. These restrictions place a limit on plant productivity and increase operating costs since
the distillation section of the plant has to remove all the water from the acetic acid product for
recycling to the reactor.
The number of limiting conditions for safe operation may be large, even for a low power
research reactor. For this reason the limiting conditions should be grouped by topic. An example
of one such grouping is as follows:
1. Fuel, fuel elements and assemblies;
2. Operating conditions which are temperature and pressure
3. Fuel handling and feed of fresh and spent fuel;
4. Reactor core configuration;
5. Reactivity and reactivity control systems;
6. Protection systems and reactor shutdown systems;
7. Fuel loading, reactor startup and operation;
8. Coolant systems and connected systems;
9. Containment systems or means of confinement, including ventilation;
10. Operational radiation protection;
11. Instrumentation and control systems;
12. Experimental devices;
13. Electric power supply systems;
14. Auxiliary systems and equipment;
1. Other limitations.
(Retrieved from International Atomic Energy Agency, 2016)

3.1.4.2 Feed Tank
Feed tank is subject to various operational constraints that make it hard to fill tanks to the top.
Storage tanks are commonly divided into feed tanks, which receive the methanol acetic acid, and
charging tanks, which feed methanol into the atmospheric distillation units
Feed tanks receive the acetic acid via a pipeline or pumped in. Methanol must normally be
allowed to stay in the feed tank for a minimum of 24 hours to allow any water mixed with the
acetic acid. In general, feed tanks cannot receive methanol from the pipeline and transfer acetic
acid to the charging tanks at the same time. Most tanks will contain a mix of different methanol
from different sources and added to the tank at different times, and track the average composition
of methanol in the tank. When a tank is discharged it cannot be emptied completely, and the
remaining acetic acid, known as the “heel”, is mixed with the next methanol parcel added.
3.1.5 Economy
Economy is defined as an area of the production, trade, distribution and consumption of
goods and services. In the control objectives of economy, the plant operation must confrom the
market condition, operation conditions are controlled at optimum levels of temperature and
pressure, minimum operating cost and maximum profit cost and less usage of energy. Basically,
the plant operation must conform the market condition in order to fulfil and satisfy the demands
of a product (market demand).
The worldwide of acetic acid market was at 12,124.3 kilo metric tons in 2015 and they are
predicted to reach 16,155.09 kilo metric tons by 2020. Asia-Pacific is the largest consumer of
acetic acid in the market with consumption up to 60.0% of the total global demand in 2015. This
is followed by North America with a considerable demand. China is the biggest consumer and is
also among the fastest-growing markets, at an estimated compound annual growth rate (CAGR)

of 5.6%. The European and North American markets shows a healthy growth with a demand
below the average market growth (PRN News Wire, 2017).
The market of acetic acid was influenced by the application of acetic acid to produce vinyl
acetate monomer, purified terephthalic acid, acetate esters, acetic anhydride, and others. Vinyl
acetate monomer (VAM) was the largest application segment for the market, which takes about
32.0% of the global acetic acid consumption in 2015. To manufacture VAM has profited over
USD 2,000.0 million with consumption more than 5 million ton in 2015 because VAM is very
demanding in the adhesive and sealant industry. Acetic acid also can be used to produce acetate
esters. It is one of the strongest growth in the market. This is influenced by the growing demand
from the coatings industry with global consumption of around 4.0 million tons in 2015.
United States is the leading country and in fact the only country in North America supplying
Acetic Acid. Meanwhile in Europe, Belgium monopoly the export of acetic acid and followed by
the United Kingdom around Europe. In Asia, the top three country that have the highest
competition is Malaysia, Singapore and China. Obviously, these country sees the opportunity in
this industry. Acetic acid was used as a base for many things. From industry purposes to the
household. Acetic acid was used to create vinyl acetate monomer which is the components of
paints and adhesive, to create esters of acetic acid that was used as solvents
for inks, paints and coatings and so on. The industry of acetic acid is a competitive industry and
the demands is increasing every year. The competition between the existing manufacture is
serious. For the past 5 years, china had monopoly the production of acetic acid in Asia Pacific.
As for now, Malaysia and Singapore are leading in the acetic acid industry in Asia.
Malaysia are generating huge demand for acetic acid consumptions. The major reasons for the
increasing demand in this region are: growing demand from paints and coatings industry, huge
request in textile and packaging industry. Meanwhile in Europe market, apparently what cause
the high demand of acetic acid was due to the lower labour cost and much cheaper raw materials.
Due to the increasing number of applications over the year, the market of acetic acid is
expected to grow even more. With the fast growing of innovative and new technology it will
create a competitive environment among the companies. These companies had to adapt and alert
to new technology to enhance their profit margins. Other than that, acetic acid was used in

cooking as well as vinegar. Vinegar consists of 4 -18 % by mass. In the future, there will always
new technology created that used acetic acid as the main component. The use of acetic acid will
increase and so does the demand. The market of acetic acid has grown a lot since the past few
years and it is estimated to grow at a considerable pace in the next five years. This is driven by
the growing demand of the worldwide as it is use to produce product that consumer used on daily
basis.
To be concluded, acetic acid is one of the most demanding product in the world. With the
growing nations, they all wanted to produce their own product because they see how they can
make a profit in this industries. Plus, acetic acid is very demanding worldwide as they can be
used for many useful reasons. From producing paints and adhesive they can also produce vinegar
which is used in cooking as well. The price of acetic acid on the market is very unstable and was
influenced by many reasons. For example, they are influenced by the seasons and problems that
occurred at the plant. Somehow, the price will increase again to meet the demand of the locals.
CHAPTER 4
PROGRESS REPORT 2
4.0 Overview
In this chapter, the PID diagram for acetic acid production is drawn and the process
description with including process measurement and feedback control are explained briefly.
4.1 PID Diagram

Figure 1: The process flow diagram of the process of methanol carbonylatio

Figure 2: PID diagram of the process methanol carbonylation for acetic acid production

4.2 Process Description (with process measurement and feedback control)
4.2.1 General Process Description
This process of methanol carbonylation is the low pressure methanol carbonylation
transformed the market because of lower cost raw materials, gentler, lower cost operating
conditions and higher yields. Reaction temperatures were 150 – 200o
C and the reaction was
conducted at 3.3 – 6.6 MPa (33 – 65 atm). Methanol Carbonylation is the preferred route even or
the industrial manufacture of acetic acid and hold to the account of 60% of the world capacity of
acetic acid. Methanol carbonylation can produce up to 95% yield of acetic acid. The cost of raw
material is also reasonable. It consists of two processes which are methanol to iodomethane, and
iodomethane to acetic acid. The process that we used was called acetica which produce more
yield than the other processes and the production cost is low compared to the others. The catalyst
that was used is rhodium. Unfortunately, the catalyst is expensive in terms of price. Methanol
carbonylation is also a low pressure process. This means less energy used and so much safer.
This method is also a preferred route in industry.

4.2.2 Process Description (with feedback control)
METHANOL INLET VALVE
Methanol enters as inlet in main feed stream and
passed through control valve. The control valve functions to
control the amount of flow in stream or pipeline where the
fail position chose is fail-to-open where valve opens at loss
of signal and this type of fail position is preferred and
chosen to prevent overpressure in event blocked line in case
catastrophic failure where the pneumatic actuator type is air-
to-close.
The desired value of pressure of 4 MPa is set to
pressure controller PC311. The pressure controller sent the
output to flow transducer, FY131 where FY131 will send the
current to flow controller, FC111 where the desired amount of methanol inlet is set. Then, the
signal from composition transmitter, ZT521 is sent to flow controller, FC111. Then, FC111 will
send signals to the control valve. ZT521 transmitted the composition of methanol to main feed
stream (methanol inlet stream) while the control valve controls the amount of methanol where
the amount is set to 31094.52 kg/hr. So, the desired composition of methanol enters main feed
stream is controlled by ZT521 and then it passed through control valve where the amount of
methanol is controlled where the amount of raw material needed in this feed stream is 31094.52
kg/hr.
REACTOR PREHEATER
The outlet of control valve which is methanol with mass flow rate of 31094.52
kg/hr enters reactor preheater where methanol is heated from temperature inlet of 25°C up to
90°C before entering reactor. After passing through preheater, methanol enters jet-stirred reactor.

JET-STIRRED REACTOR
In the jet-stirred reactor, R101, the reaction occurred where the catalyst used is Iridium
which methanol is reacted with carbon monoxide and is converted to unreacted methanol,
unreacted carbon monoxide and acetic acid with mass flow rate of 14303.48 kg/hr, 14303.48
kg/hr, 33582.09 kg/hr and 3272.70 kg/hr, respectively, for the first outlet stream while for second
outlet stream the product is acetic acid, iridium and water with mass flow rate of 52369.4 kg/hr,
3272.695 kg/hr and 9819.655 kg/hr, respectively. The operating condition of jet-stirred reactor is
90°C and 4 MPa. At jet-stirred reactor, there is a pressure transmitter, PT321 mounted on the
reactor and PT321 transmitted the signal to pressure controller, PC311 so that the PC311 can
control the flow controller, FC111 by receiving the signal from flow transducer, FY131 first in
order to control the methanol inlet. Whenever the pressure at jet-stirred is higher than its’
operating condition of 4 MPa, the pressure controller, PC311 will send signals to the flow
controller, FC111 to decrease the mass flow rate of methanol inlet.
This jet-stirred reactor is made from Pyrex glass or Fused silica which no corrosion will
occur since our production is acid which can cause corrosion to the equipment. The reactor no
need insulation because the temperature is below than 100˚C where our operating pressure is
high which 4 MPa (high pressure help maintain the temperature where the increase the pressure,
the increase the temperature according to Ideal Gas Law). The advantages of this reactor are it
very suitable for gaseous material and has efficient in mixing of the gas phase (identical and
homogenous composition outlet or inlet inside reactor).
The level transmitter, LT221 is mounted on the reactor tank in order to control the level
of flow in the reactor. When the level of the flow inside the reactor reached or over the flow
limits, the level flow, LT221 will signal for safety precautions.
This reactor preheater will send the current signal to temperature transducer, TY431
where the transducer will do split range and send signal to flow controller, FC411, reactor
preheater of methanol inlet and reactor preheater for carbon monoxide inlet. From flow
controller, FC411, the signals is received from flow transmitter, FT121 where FC112 controls
pump while FT121 transmits the signal to stream.

The operating pressure is set to pressure controller, PC311 at the monitor. Then PC311
receives the signals from flow transducer, FY132 then it send the signals to flow controller,
FC113. This flow controller FC113 controls the amount of flow by controlling the control valve
of carbon monoxide inlet where desired amount of 31094.52 kg/hr of carbon monoxide is
required in this second feed stream. Next, FC113 received signals from composition transmitter,
ZT522 so that the composition of carbon monoxide is controlled and set to the desired amount
before the desired composition of carbon monoxide needed enters the control valve.
After passed through control valve, carbon monoxide will pass through reactor preheater
where the carbon monoxide is preheated from 25°C up to 90°C before entering reactor. This
preheater is controlled by temperature controller, TC411 at monitor. TC411 receives signals from
temperature transmitter, TT421 which is mounted on the jet-stirred reactor. TT421 transmitted
the signals to the TC411. Then, TC411 received the signals from TY431 which do the split range
with preheater for methanol inlet, carbon monoxide inlet and preheater for first outlet stream of
reactor. Then, TY431 which is connected to preheater sent the signals to preheater to heat up the
carbon monoxide. For example, when temperature of reactor is decrease below the operating
temperature, the temperature transmitter will detect the changes and send this to temperature
controller, TC411 to increase the reactor temperature. This signal is sent from temperature
transducer, TY431 which will control the both reactor preheater for carbon monoxide inlet and
methanol inlet. These signals from TY431 also connected with reactor preheater for catalyst inlet
where TY431 do the split range. From pump, the catalyst rich recycle stream, 3272.70 kg/hr of
catalyst is passed through reactor preheater to be preheated from 25°C up to 90°C and then
pumped into reactor. This reactor preheater is connected with TY431 and preheater for carbon
monoxide.
The first outlet of reactor unreacted methanol, unreacted carbon monoxide and acetic acid with
mass flow rate of 14303.48 kg/hr, 14303.48 kg/hr, 33582.09 kg/hr and 3272.70 kg/hr,
respectively. These components are pumped into main feed stream as reflux. At pump, the outlet
flow is controlled by flow controller, FC113 which receives signals from flow transmitter,
FT121. Next, these components passed through reactor preheater to be heated at 90°C which the
temperature of preheater is controller by temperature controller, TT411 which send signals to

temperature transducer, TY431 where TY431 do the split range of current. Then, the components
are entering the reactor to be reacted again in the main feed stream with pure methanol inlet.
Lastly, at second outlet stream the product is acetic acid, iridium and water with mass flow rate
of 52369.4 kg/hr, 3272.695 kg/hr and 9819.655 kg/hr, respectively. These components exit the
jet-stirred reactor and passed through the pump to enter the second reactor of plug flow reactor
(PFR) for the second reaction.
PROCESS DESCRIPTION OF INLET OF PLUG FLOW REACTOR (R102) UNTIL
RECYCLE PATH OF FLASH TANK (T301)
The product from R101 will be entered the pump. Pump is operated by movement of
liquid. It produces the flow necessary for the development of pressure which is a function of
resistance to fluid flow in the system (Hydraulic & Pneumatics, 2012). The flow of chemical is
then entered pre-heater so that the chemical have sufficient minimal amount of heat so that
reaction may occurred in reactor R102. The flow of chemical from pump towards R102 will be
monitor by automatic by using electrical signal. The signal is referring to pressure controller
(PC312) and pressure transmitter (PT322) of the chemical that entered the R102. The closed and
open of valve for flow of chemical towards R102 will be determine by PC312 and PT322
according to drop or rise of pressure in the system. During pre-heater, the signal will be control
by pneumatic signal which use gas or air as the signal medium (Kendrion, n.d). The pneumatic
signal is then converted to electrical energy by transducer (TY432) and the electrical signal
constantly controlled by temperature controller (TC412) and temperature transmitter (TT422) of
the system. If the chemical is increase in temperature, TT422 will be sense the different by their
set point and actual temperature and will send signal towards pre-heater to be switch off to
reduce the temperature of the system. The same application applicable if there is decrease in
temperature of the chemical in the process system. This way of backword and forward controller
is widely used in chemical industry. This type of controller is to protect the master from become
wear which applied the slave to recognize the problem and provide solution before the master
being disturbed by the problems. If that happened, the highest maintenance will be needed to
provide solution of the process. In R102, the reaction will be occurred in maximum operating
temperature is 500 0
C and maximum operating pressure is 2psig. The product of the reactor will

be flow through pump and then through the control valve. During this transition, the flow of
product chemical from R102 will be controlled entirely by electrical signal. The movement will
be controlled by present of pressure controller (PC313), pressure transmitter (PT323, flow
transducer (FY134), flow transmitter (FT124) and flow controller (FC116). The present of this
entire controller is necessary so that the system is stable throughout the process. If there is
increase in pressure in the system, the signal will be send to valve so that it will be opened or
closed according to command given. Same way will be applied for changes of flow of
chemical in the process system. The product chemical from R102 will be entered flash tank
(T301) to undergo further processes. The chemical that entering in recycle process that occurred
in T301 will be through the pump and the flow is controlled by electrical signal of flow
transducer (FY133), flow transmitter (FT122) and flow controller (FC114). The signal will
control the flow of chemical inside the jet reactor (R101). The flow of chemical from recycle
path at flash tank (T301) that through the pump that the chemical flow is control by electrical
signal is then through the pre-heater and then recycle back to the jet reactor (R101) and
undergoes reaction process in that reactor.
Figure 1: Process description of inlet of Plug Flow Reactor (R102) until recycle path of
Flash tank (T301)

PROCESS DESCRIPTION OF DISTILLATION COLUMN AND PURIFICATION
COLUMN
FRACTIONATING COLUMN
In C201(fractionating column), the condition
needed to operate was the temperature must reach
100˚C and the pressure was at 1 atm. Thus, the set
point was set up at 100˚C and 3 instruments was
installed to control the temperature to the desired
value. The temperature transmitter (TT423) will
detect and monitor any increase or decrease of the
temperature in the fractionating column. If there is
any decrease or increase of the temperature, the
transmitter will detect the problem and sends a
signal to the temperature controller (TC413).
Temperature controller will decide and take a suitable action. The action will go through the
temperature transducer (TY433) to translate and convert the action into an electric signal so that
the heat exchanger can read the signal and take action. It was called the pneumatic signal.
In the fractionating column, the mixture of acetic acid, iodide and water was separated into two
stream which are water stream and crude acetic acid stream. For the water stream, water that
gives out was in a gas phase(vapour). The flow of the water vapour was monitor by the flow
transmitter (FT123). If there is any problem with the flow, the flow transmitter will send out a
signal to the flow controller (FC115) to take an action. As you can see in the P&ID, the control
valve was connected to the flow controller. Thus, after the controller decide what type of action
needed to take, the control valve will perform the action to control the flow. The level of the
water vapour was also controlled by the level controller (LC211). This is a feedback system.
For the crude acetic acid stream, the flow was monitor by the flow transmitter (FT125).
Whenever there is any increase or decrease in the flow, the transmitter will detect and monitor
the problem and sends the signal to the flow controller (FC117) to take an action. As you can see
the control valve was connected to the flow controller. Thus, when the flow controller decide

what type of action that needed to take, the control valve will perform the action for the
controller. This is also a feedback system.
PURIFICATION COLUMN
The inlet for purification column (C202) is the crude acetic acid. The function of purification
column is to purify the crude acetic acid composition by using ion exchange resin composition
that compose of active and non-active site. The desired operating condition for the purification
column is at 50˚C in 1 atm. The set point was at 50˚C and to maintain the temperature, a
temperature transmitter (TT424) was installed at the inlet stream of the purification column. The
temperature transmitter will detect and monitor any increase or decrease of the temperature. If
there is any increase or decrease in the temperature, the temperature transmitter will sends the
signal to the temperature controller (TC414). The temperature controller will accept the signal
and decide and take a suitable action to overcome the problem. The action will be translated and
converted to an electrical signal so that the heat exchanger can read the signal and perform the
action by the temperature transducer (TY434). It is called the pneumatic signal. Thus, the
temperature was controlled.
There are two outlet streams in the purification column. The first stream is the acetic acid stream
and the second stream is the by-product (propanoic acid) stream. The flow of acetic acid stream
was monitored by the flow transmitter (FT126). The flow transmitter will monitor and detect any
increase or decrease flow in the acetic acid stream and sends the signal to the flow controller to
decide and take a suitable action. As you can see in the P&ID, the control valve was connected
directly to the flow controller. When the flow controller decide what type of action needed to
take, the control valve will perform the action. That is how the flow of acetic acid was
controlled. This is a feedback system.
For the second outlet stream, (propanoic acid) the flow of the propanoic acid was also monitored
by the flow transmitter (FT127). The flow transmitter will detect and monitor any increase or
decrease of the flow and sends the signal to the flow controller (FC119). The flow controller will
receive the signal and decide what type of action needed to take. As you can see in the P&ID, the
control valve was connected directly with the flow controller. After the controller decide what

type of action needed to take, the control valve will perform the action. The flow was controlled
by using a feedback system.
CHAPTER 5
PROGRESS REPORT 3
5.0 Overview
In this chapter, the three control strategies for three selected major equipments are decided
and described. The control strategies are feedback system, feed forward system and inferential
system while the major equipment are plug flow reactor, fractionation column and purification
column.
5.1 Control Strategies
5.1.1 Plug Flow Reactor
Plug flow reactor has no back mixing or axial mixing. Polymer plug flow reactors use
inline equipment such as pipes or tubes in production process. Since there is no back mixing, all
of the components in the reaction mass exit at the same time that is equal to the transportation
delay. All of the residence time becomes a process dead time. A plug flow reactor consists
generally no level control and the residence time distribution is extremely tight. If consider a
subsection of the reaction mass moving from the entrance to the exit, there is no discharge from
this volume until the subsection approaches the exit (Greg McMillan, n.d). For production of
acetic acid, plug flow reactor can be describes as below:

Figure 3: Plug Flow Reactor of production of acetic acid
From figure 1 above shows the controller exists in production of acetic acid. Around plug flow
reactor, there are pressure and temperature controller. Basics of inferential control are all sensors
are in some sense inferential. Conventional sensors measure "true" process variable is depend on
reasonable accuracy and reproducibility. Inferential advantages are including faster response and
lower cost.
Figure 4: Blok Diagram of Inferential controller

By using inferential method, process measurement can be obtained more rapidly with a
mathematical model called soft sensors to infer the value of CV. It consists of X and Y which X
is 2nd
measurement which are fast sampling and Y is 1st
measurement also known as master. The
best reason to use this type of control strategy is the cost on on-line analyzers used to measure
primary variables can be excessive. Other than that, analyzers that measure secondary variables
are typically less expensive and easier to maintain.
5.1.2 Fractionation Column (C201)
Figure 5: Fractionation column (C201)
In production of acetic acid, there is a fractionation column used in this process. It
functions to distillate liquid mixtures so as to separate mixture into its component parts or
fractions based on the differences in volatilities and boiling point where the temperature are
controlled in this process as well as flow rate.

Figure 6: Standard block diagram of feedback control system
The control strategy used in this process is using automatic controller of feedback system
which it is also known as closed loop control system and it functions to make decisions about the
changes to control signal that drives the plant and are widely use in industry.
In this system, the feedback system is used to change temperature entering and leaving
the fractionation column. During the process in the, disturbance will occur. Current process
variable and disturbance are combined and acted as process output where it will be measured by
sensor. Then, transmitter (TT423, TT424, FT123 and FT125) will convert to input signal where
transmitter transmits signal to transducer (TY433 and TY434), respectively. Controller (LC211,
FC215, TC413, FC117 and TC414) will evaluate the measurement where if any error exist,
controller will take corrective action immediately by manipulating control element.

Figure 7: Block diagram of feed forward control system
Besides, another automatic controller that is also can be used for this equipment is feed
forward controller. Feed forward system is pro-active which the reaction only happened when
there are some errors. Feed forward functions to control flow rate as it is used to measure
important variable and take action before the process upset. In contrast, feedback controller does
not take corrective action until disturbance has upset the process as feed forward system could.
However, feed forward also can provide better control of flow rate that entering and
leaving fractionation column. Several advantages when using this control system are compensate
for disturbance before effect is seen and works well with slow process, where the system require
less than 2 atm to separate its components and corrective action occurs as soon as controlled
variable deviates from set point where it means that this feed forward system can detect any
disturbance before effect is seen, which very important for fractionation column in this acetic
acid production in order to produce acetic acid with 99 % yield and 100% purity and also to
ensure the process is zero disturbance occurred in order to get the desired product.
The limitations of this feed forward system is disturbance must be measured on line and
must to know control variable respond to change in disturbance and manipulated variables must
be taken into considerations.
5.1.3 Purification Column (C202)

In purification column, the process of purifying crude acetic acid
composition comprising acetic acid and iodides. The crude acetic acid
composition was contacted with an ion exchange resin composition that
comprises of active and non-active region. The active region consists of
carrier gasses which are helium, nitrogen, argon, hydrogen and air. Thus,
the control strategies that was applied in this equipment is called flow
ratio control.
In this process design and operations keeps two flow rates. One of the
flows in a ratio-control is the master flow or wild flow. The ratio
controller manipulates the other flow to maintain the desired ratio
between two flows. The flow controlled by the ratio controller is called
the controlled flow. In this case, the wild flow is the acetic acid flow and
the iodide is the controlled flow. In this way, we can maintain the
stoichiometric ratio of reactants to a reactor. Regardless of how ratio
control is implemented, the process variables must be scaled appropriately.
The quality of the acetic acid produced was excellent with low in organic iodide impurities.
Thus, much less energy is required to purify the product. Ion-exchange resins are widely used in
purification especially. Ion-exchange processes are used to separate and purify metals. In this
case the metal that we need to purify is iodide. Ion-exchange was for many years the only
practical way to separate the rare earths in large quantities. The ion-exchange process is also used
to separate other sets of very similar chemical elements.

REFERENCES
1. Greg McMillan. (n.d). What are the Implications of Reactor Type on Control? Retrieved
January 22, 2017, from ISA Interchange: http://automation.isa.org/2014/12/what-are-the-
implications-of-reactor-type-on-control/
2. International Atomic Energy Agency. (2017). Operational Limits and Conditions and
Operating Procedures for Research Reactors. Retrieved from http://www-
pub.iaea.org/MTCD/publications/PDF/Pub1333_web.pdf
3. Disinfection Digest. VigorOx WWTII – Wastewater Disinfection Technology. (3 August
2014). http://www.peroxychem.com/media/109053/aug2014_paa_residuallimits.pdf
4. Michael V. Petrovich. (n.d). STRATEGIES FOR IMPROVEMENT OF PROCESS
CONTROL. Retrieved January 22, 2017, from mvpprograms:
https://mvpprograms.com/docs/procctrl.pdf

5. MSDSonline. (2014, November 19). Acetic Acid Hazards & Safety Information.
Retrieved January 1, 2017, from VelocityEHS: https://www.msdsonline.com/blog/health-
safety/2014/11/19/acetic-acid-hazards-safety-information
6. National Pollutant Inventory. Australian Government, Department of Environment and
Energy. (2 June 2014). http://www.npi.gov.au/resource/acetic-acid-ethanoic-acid
7. NIOSH. (n.d). ACETIC ACID. Retrieved January 1, 2017, from The National Institute of
Occupational Safety and Health: https://www.cdc.gov/niosh/ipcsneng/neng0363.html
8. PARR. (n.d). THE USER’S RESPONSIBILITY. Retrieved January 2, 2017, from
SAFETY in the Operation of Laboratory Reactors and Pressure Vessels:
http://www.offices.research.northwestern.edu/ors/safety/chemical/from_parrreactorsafety
info-230m.pdf
9. PRN News Wire. (2017). Global Acetic Acid Marker. Retrieved from
http://www.prnewswire.com/news-releases/global-acetic-acid-market---segmented-by-
application-and-geography---trends-and-forecasts-2015-2020---reportlinker-review-
300145381.html
10. Zulhafiz Tajuddin. (2017). Process dynamics and control. Chapter 3 control strategy part
1. UniKL MICET, Melaka.
11. Hydraulic & Pneumatics. (2012, January 1). Engineering Essentials: Fundamentals of
Hydraulic Pumps. Retrieved January 9, 2017, from Hydraulic & Pneumatics:
http://hydraulicspneumatics.com/200/TechZone/HydraulicPumpsM/Article/False/6401/Te
chZone-HydraulicPumpsM
12. Kendrion. (n.d). Kuhnke Pneumatic Signal Indicators and Converters. Retrieved January
9, 2017, from Kendrion:
https://www.kendrion.com/sweden/industrial/en/products/pneumatic-fluid-
technology/pneumatic-control-units/pe-converter.html

APPENDICES

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