Table of ContentsChaper 1...........................................................................................................................................4

1.1. Company Profile...............................................................................................................5

1.1.1. Pak China Chemicals.................................................................................................5

1.1.2. Quality Assurance Program.......................................................................................5

1.1.3. Quality Control..........................................................................................................6

1.1.4. Pak China Polymers...................................................................................................6

1.2. Progress.............................................................................................................................6

Chaper 2...........................................................................................................................................7

2.2. Products.............................................................................................................................8

2.3. Capacity............................................................................................................................8

2.4. Raw Materials for Emamectin benzoate...........................................................................8

2.5. Main Steps Involved in Emamectin benzoate production................................................8

2.6. Process description............................................................................................................9

2.7. Process Flow Diagram....................................................................................................11

2.8. Operating temperatures and the time history..................................................................14

2.9. Utilities for EB production plant.....................................................................................19

Chaper 3.........................................................................................................................................21

3.1. Introduction:....................................................................................................................22

3.2. Raw Materials.................................................................................................................22

3.3. Process Description.........................................................................................................22

3.4. Process Flow Diagram....................................................................................................23

3.5. Plant description..............................................................................................................24

3.6. Description of Plate and frame filter press......................................................................24

Chaper 4.........................................................................................................................................26

4.1. Introduction:.......................................................................................................................27

4.2. Capacity..........................................................................................................................27

4.3. Products...........................................................................................................................27

4.4. Production of Emulsifiable Concentrate and Soluble Liquid:........................................27

4.5. Production of Soluble Concentrate, Emulsion Wet and Soluble Emulsion:...................28

4.6. Process Flow Diagrams...................................................................................................29

4.7. Utilities for liquid formulation plant...............................................................................31

4.7.1. Diaphragm pumps....................................................................................................31

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4.7.2. Strainers...................................................................................................................32

4.7.3. Bead Mill.................................................................................................................32

4.7.5. Flux Well Joints:......................................................................................................33

Chaper 5.........................................................................................................................................34

5.1. Introduction:....................................................................................................................35

5.2. Capacity:.........................................................................................................................35

5.3. Products:..........................................................................................................................35

5.4. Raw Materials.................................................................................................................35

5.5. Sticker solutions for Products:........................................................................................35

5.5.1. Sticker Solution for Mono mehypo hydrochloride:.................................................36

5.5.2. Sticker Solution for Cartap hydrochloride...............................................................36

5.5.3. Sticker Solution for Carbofeuron.............................................................................36

5.6. Process description..........................................................................................................36

5.7. Block Diagram................................................................................................................37

5.8. Equipment description:...................................................................................................39

Chaper 6.........................................................................................................................................41

6.1. Introduction:....................................................................................................................42

6.2. Steps in Refrigeration Cycle...........................................................................................42

6.3. Block Diagrams:.............................................................................................................43

6.4. Process Flow Diagram:...................................................................................................44

6.5. Equipment Description:..................................................................................................45

6.5.1. Compressor:.............................................................................................................45

6.5.2. High pressurized ammonia container (Receiver):...................................................46

6.5.3. Evaporator................................................................................................................46

6.5.4. Accumulator............................................................................................................46

6.5.5. Condenser:...............................................................................................................47

6.5.6. Throttling Devices:..................................................................................................47

6.5.7. Oil Separator:...........................................................................................................48

6.5.8. Air Separator:...........................................................................................................49

6.5.9. Inter Cooler:.............................................................................................................49

Chaper 7.........................................................................................................................................50

7.1. Introduction:....................................................................................................................51

7.2. Boiler Description...........................................................................................................51

7.3. Process Flow Diagram for Boiler House:.......................................................................53

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7.4. Water Softener:...............................................................................................................54

7.5. Boiler Maintenance:........................................................................................................54

Chaper 8.........................................................................................................................................55

8.1. Introduction:....................................................................................................................56

8.2. Facts of safety & health in a chemical industry:.............................................................56

8.3. Protection zones (explosion protection, separation distances):......................................56

8.4. Setup of fire and safety at Pak China Chemical Plant:...................................................57

References:....................................................................................................................................58

Chaper 1

3

Introduction to ALI AKBAR GROUP OF PAKISTAN

1.1. Company Profile:

Agriculture is the backbone of Pakistan's economy. Keeping in view the ever increasing demand for quality agricultural inputs, the company was established in 1993 by the group of people with the vision,

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wisdom and professionalism to foresee the importance of food sufficiency in enhancing quality of life for better tomorrow. Initially, the core business of the company was manufacturing and marketing of agrochemicals but within the short span of 17 years, Ali Akbar has grown exponentially and now comprises a group of companies offering a diverse range of products and services.

Category of business:

Production of pesticides Import of pesticides Export of pesticides Distribution of pesticides Textiles

Today, Ali Akbar Group is a leading crop protection company in Pakistan and comprises of a diversified group of five companies having its Head Office in Lahore, including:

1.1.1. Pak China Chemicals:

Pak China Chemicals, a project of Ali Akbar group has the largest and the most modern pesticide series of formulation plant in Pakistan with liquid formulation capacity of more than 300,000 liters per day, granules 80,000 kg and powder 8,000 kg per day production capacity. Other then formulation, the main production plants are of;

Emamectin Benzoate Zinc Sulphate

All the plants are highly equipped with process control instrumentation. All the machinery and equipment is of explosion prove grade. The packaging units are completely automatic and formulation area has designed to meet OSHA, USA requirements for occupational health and safety. The plant has a finished product storage facility of 1,600,000 liters at one time. The storage areas are well ventilated and equipped with fire safety detection. This is the first ever EPA approved and ISO 9000-2001 certified plant in Pakistan.

1.1.2. Quality Assurance Program:

The quality assurance program is based on ISO 9001-2000 quality management system. The quality loop starts with supplier evaluation and selection. It includes all stages from receiving, in process management of raw materials to finished products. The final stage consists of quality assurance customer’s premises and final analysis at the point of use through a network of mobile testing laboratories.

1.1.3. Quality Control:

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A well-equipped pesticides laboratory monitors quality of products as well as that of imported agrochemicals. The laboratory is operated by highly experienced Chemists, and is equipped with latest equipments/instruments for all types of tests.

1.1.4. Pak China Polymers:

In 2005, Ali Akbar Group installed a state of art PET Bottle manufacturing unit at their premises at Manga Mandi. This facility is capable to cater for the rising PET bottle demand in following fields:

Carbonated soft drinks Mineral water Edible Oils Agro Chemicals

The facility is equipped with technological advanced equipment developed over a period of many years of experience in the field by the leading manufacturers of PET equipment. These advanced technologies contain but not limited to following:

Injection Machine from Krupp, Germany Blowing Machine Blowmax-6 Series from SIQ Corp plastic, Germany

The technological superiority of these machines gives certain advantages to this facility over other manufacturers of PET bottles in Pakistan. The reliability and process control system provide consistent quality. At time of delivery and after sales, services of the company combines into a winning solution for the customers.

1.2. Progress:

They started marketing of agrochemical since 1993, as natural response to the opportunity arising from the ever-growing demand for crop protection chemicals in Pakistan. First direct sale was carried out at the end of 1993 with improved Methyl Parathion. From 1993 up till now they are offering a comprehensive range of products such as herbicides, fungicides, matricides and plant growth regulators every year.

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Chaper 2

PAK CHINA MANUFACTURING (PCM) PLANT

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2.1. Introduction:

In 2005, a state of art PCM plant is installed with the aim of producing micro nutrients and pesticides for the plants. All the technology is used in the plant is imported from China. Regular check and balance is done by Chinese engineers in every six months. As the raw materials used in this plant are highly explosive, all safety measures have been introduced in order to avoid any accident.

2.2. Products: Emamectin benzoate Liquid humic acid8% w/w

2.3. Capacity:

The plant operates in batch wise manner, with capacity of producing 2800 ltrs/day.

2.4. Raw Materials for Emamectin benzoate:

Hence the list of all raw chemicals required for manufacturing of Emamectin benzoate is given as;

Abmectin Dichloromethane(solvent) Isopropyl Alcohol(solvent) Phosphroic acid Sodium bicarbonate A: Trifloroacitic acid B: Triphenylphosphine palladium C: Allylchloroformate D: Tetra ethyl lanemethyldiovrine E: Dimethyl sulphoxide F: Phenyldichlorophosphate G:Heptamethyldislazane H: Sodium borohydride Ethanol Ditomate Brine Solution at -15 digree C and at -40 digree C.

2.5. Main Steps Involved in Emamectin benzoate production:

Stage 1:

Demoisturization and Protection Oxidation Neutralization and separation

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Distillation

Stage 2:

Aminization Deoxidation Removal of protection Neutralization and separation

Stage 3:

Distillation Addition of benzoic acid to get emamectinbenzoate

2.6. Process description:1) First of abmectin along with the solvent DCM (Dichloromethane) and chemicals C, D, E,

F is added in the reactor R1 where three following three processes are done, Moisture control Protection reaction Oxidation reaction

2) Moisture percentage is set at <0.05%.3) Oxidation reaction happens due to chemicals E, D, F whereas protection reaction due to

C and D.4) Product is then transferred to reactor R2 or reactor R3 that are standby reactors of each

other with the help of vacuum pumps where neutralization of acid and base is done. Acid and base used are phosphoric acid and baking soda respectively. When acid and base are neutralized two layers are formed organic and inorganic. Organic layer is removed and is stored in the storage tanks T1 and T2, whereas inorganic layer which is normally water is drained out.

5) Organic layer is then transferred to reactor R4. Here distillation is done in order to remove solvent by applying low and high vacuum. Solvent is removed in vapor form, condensed by the condenser E1 and stored in tanks T3 and T4.after this there is addition of another solvent IPA (Isopropyl acetate) in R4. Moisture is controlled here also <0.05%.

6) Product from reactor R4 is then transferred to reactor R5 where ammonization (addition of amino group) is done using catalyst (A) and reactant (G). Temperature maintained here is 55-65 degree C.

7) Product is than shifted to reactor R6 where two main processes occurs,

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De oxidation Removal of protection

8) De oxidation is done using ethanol and H.Removal of protection is done using ethanol, H and catalyst (B).

9) During these processes particles are dispersed in the whole solution which is removed in the next reactor.

10) In R7 or R8 that are standby reactors of each other there is addition of diatomaceous earth along with acid and base. diatomaceous earth collect the particles dispersed in the solution and the product is send to centrifuge 1 or 2 where the particles in the solution are removed and clear solution is again send to reactor R7 or R8 where organic layer is separated from inorganic and is transferred to Reactor R10 or R11 that are standby of each other. Inorganic layer is drained out.

11) In R10 or R11, benzoic acid is added in in order to obtain emamectin benzoate. DCM and IPA are recovered by distillation, condensed by condensers E2, E3 and E4 and stored in storage tanks T11, T12 and T13, T14, T15 respectively.

12) If product is in powdered form it is taken in trays and dried in tray dryers using steam.

13) Product packing is done and transferred to market.

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2.7. Process Flow Diagram:

Figure 2.1: PFD for stage 1

R1: Reactor 1 TP: Storage tank of H3PO3 C: AllyalChloroformateR2: Reactor 2 T1: Storage tank 1 D: Tetra ethyl lanemetyldiovrineR3: Reactor 3 T2: Storage tank 2 F: Phenyl phosphrodichloridateR4: Reactor 4 T3: Storage tank 3R5: Reactor 5 T4: Storage tank 4

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Figure 2.2: PFD for stage 2

R5: Reactor 5 T6: Storage tank 6 G: AllyalChloroformate R6: Reactor 6 T7: Storage tank 7 A: Tetra ethyl lead R7: Reactor 7 T8: Storage tank 8 B: Phenyl phosphrodichloridate R8: Reactor 8 T9: Storage tank 9 H: T5: Storage tank 5 T10: Storage tank 10

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Figure 2.3: PFD for stage 3

R9: Reactor 9 T13: Storage tank 13 IPA: Isopropyl AlcoholR10: Reactor 10 T14: Storage tank 14 E2: Condenser 2R11: Reactor 11 T15: Storage tank 15 E3: Condenser 3T11: Storage tank 11 T9: Storage tank 9 E4: Condenser 4T12: Storage tank 12 T10: Storage tank 10

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2.8. Operating temperatures and the time history:

As the process is highly temperature dependent, so it is required to mention total temperature history for the whole process. Time for each process in the production of emamectin benzoate is of considerable importance because batch processes are always characterized by their time.

The following tables give a complete illustration for the operating temperatures for whole process involved and their reaction times.

Table 2.1

Table 2.2

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Removal of moisture

Process Temp (Celsius) Time (min)

Addition of Abmactin & DCM Room temperature 10

Removal of moisture 40-50 25

Protection

Process Temp (Celsius) Time (min)

After demoisturization<0.05% 45 0

Addition of C solution (half) -20 10

Reaction -22 30

Addition of C and D solution -15 to -20 25-30

Reaction for protection -15 to -20 15Oxidation

Process Temp (Celsius) Time (min)

After protection is Ok -20 0

Addition of D & E -20 Immediately

Addition of F -15 to -20 15

Reaction for oxidation -15 to -20 120

Table 2.3

Table 2.4

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Neutralization and Separation

Process Temp (Celsius) Time (min)Product + Phosphoric Acid (2% Solution) pH=2-3 No control 15

Agitation No control 10

Settling No control 90

Separation No control 15

Addition of Sodium bicarbonate 20% solution in organic phase No control 30

Agitation No control 10

Settling No control 90

Separation No control 15

Aminization Reaction

Process Temp (Celsius) Time (min)

After moisture <0.05% 20 0

A) Addition of G and A 20 Immediately

Reaction of Aminization 55 120 Table 2.5

Table 2.6

Table 2.7

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Deoxidation

Process Temp (Celsius) Time (min)

After Aminization is Ok 55 0

Addition of Ethanol -10 ImmediatelyAddition of H (Nitrogen Protection) -15 30Reaction for deoxidation

-10 65

Removal of Protection

Process Temp (Celsius) Time (min)

After Deoxidation is Ok -10 0

Addition of Ethanol -10 Immediately

Addition of B (Catalyst) -10 Immediately 

Addition of H -5 to -10 20 to 30 

Reaction for Protection Removal -5 to 5 65 

Separation

Process Temp (Celsius) Time (min)Product + Acetic Acid (12% Solution) -5 40

PH (5~6) -5 5-15

Agitation -5 10Addition of NaOH (10% Solution) -5 10

Agitation No control 15

Settling No control 180

Addition of Ditomate No control 5

Agitation No control 30

Filtration by centrifuge No control 120

Received R-7 No control 10

Agitation No control 30

Settling No control 60

Separation No control 30

Table 2.8

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The Figure 2.4 shows the distribution of pipelines for temperature control in the reactors. Following are the color codes for various pipes line expressed in Figure 2.4.

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2.9. Utilities for EB production plant:Following is the list of utilities used in production plant of emamectin benzoate.

Batch reactors Maximum capacity: 2000litre Inner layer: Stainless steel

Glass lining for separation vessels Outer jacket: Stainless steel with polyurethane insulation Type of agitator: Propeller

Strainers Type of drying agent: Silica gel Usage: To remove moisture for incoming air

Vacuum Pumps No. of Vacuum pumps: 9 Pressure developed: -1bar

Condensers No. of condensers: 4 Material of construction: Stainless steel

Centrifuge Type of centrifuge: Filtering type RPM:1800-3600

Diaphragm pumps Type of diaphragm pump: Double acting Type of diaphragm: Teflon

Other common utilities are:

Storage vessels Ball and gate valves Stainless steel pipelines Glass wool insulation Pressure gauges Temperature gauges Level sensors

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Chaper 3

20

ZINC SULPHATE PLANT

3.1. Introduction:

Zinc sulfate (ZnSO4) is a colorless crystalline, water-soluble chemical compound. The hydrated form, ZnSO4•7H2O, the mineral goslarite, was historically known as "white vitriol" and can be prepared by reacting zinc with aqueous sulfuric acid. The product is 10% zinc sulphate. This is mainly use directly as a pesticide and sometimes ingredients are added in it.The product is in form Liquid form

3.2. Raw Materials:

Following are the raw materials for Zinc sulfate.

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Zinc Ash Raw water Sulphuric acid

3.3. Process Description:

98% concentrated sulfuric acid is charged in a storage tank through centrifugal pump. Again through centrifugal pumps which are connected at the outlet of storage tank Sulfuric acid is

taken into calibrated storage tank (overhead tank). In calibrator connected with the tank, a known amount of sulfuric acid is taken. This amount of

sulfuric acid depends upon the batch which will be taken out. From calibrated sulfuric acid storage tank the acid is sent into the reactor by gravity action. Then a known amount of raw water is fed into the batch reactor. Than measured amount of Zinc Ash is also fed into the reactor. This zinc ash is dropped manually

in the reactor. Than residence time of 2-3 hours is given in the reactor. Agitation is done by blade type agitator. Reaction between Sulfuric acid and zinc takes place and zinc sulfate is formed according to

the following reaction.

o H2SO4 (aq) + Zn ------------- > ZnSO4 + H2

This is an exothermic reaction, heat and lots of fumes are evolved during the reaction After 2-3 hours zinc sulfate is taken into Pit. Here the solution is given time to settle down. Dust particles settled down and product is tested from laboratory, if there is need of more

mixing than it is done through compressed air. The solution from Pit is sent into the Plate and frame filter press through the high Pressure

centrifugal pump. After filtration, a pure solution of 10% zinc sulfate is taken into tanks.

3.4. Process Flow Diagram:

22

Figure 3.1: PFD of Zinc Sulphate plant

3.5. Plant description:

Percentage yield 95% (average)

Type of reactor Batch

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Construction material of reactor Mild steel innerly lined with ceramics bricks

Reactor Capacity 13 ton

Production per batch 10 ton

Total production rate 30ton/day

Type of pumps used Centrifugal pumps

Type of agitator in reactor Helical

Type of filter Plate and frame filter press

Number of plates (of filter press) 35

Table: 3.1

3.6. Description of Plate and frame filter press:

It is a type of filter, used to separate suspended particles in fluids. A filter press consists of a series of chambers containing rectangular filter plates supported in a

frame. The plate is wrapped with filter medium

(diaphragm or membrane). This is main wall, which acts as a sieve. The fluid enters at the inlet at the point of feed. Particles settle on the filter medium as cake and

clean fluid moves out. Filter presses generally work in a "batch"

manner. The plates are clamped together, and then a pump starts feeding the slurry into the filter press to complete a filtering cycle and produce a batch of solid filtered material, called the filter cake. The stack of plates is opened, solid is removed, and the stack of plates is re-clamped and the filtering cycle is repeated.

Other common utilities used in Zinc sulphate plant are: Valves Centrifugal pump Storage tank Batch reactor Diaphragm pump

24

Figure 3.2

Sedimentation tanks Level sensors

Chaper 4

25

LIQUID FORMULATION PLANT

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4.1. Introduction: The formulation plant mainly deals with the production of liquid phase pesticides. The plant mainly consists of batch reactors and pumps for the requirement of the product. The plant is equipped with the best process control instrumentation. All the machinery and equipment is of explosion prove grade.

4.2. Capacity: Formulation capacity: 300,000 liters of liquid/day Finished product storage capacity: 1,600,000 liters at a time

4.3. Products:

Emulsifiable Concentrate: Cypermethrane 10EC

Triazofast 40EC Soluble Liquid:

Imidachloroprid 20SL Acetamyprid 20SL Glyposate 48SL

Soluble Concentrate: Diaphrenthrun 50SC Atratox 38SC

Emulsion Wet: Tegula 12.5 EW Phenoxaprop-p-ethyl 6.9 EW Break 7.5 EW

Soluble Emulsion: Weed out 40SE

4.4. Production of Emulsifiable Concentrate and Soluble Liquid:

The raw material (technical, emulsifier) is preheated in hot water bath up to its flow able temperature.

Solvent required here is same as which is to be used for the product formulation e.g. (Xylene, Di-methyl sulphoxide, Reverse osmosis water, Di-methyl formamide). Mostly Xylene is used.

All the concerned valves are then checked before the charging of the solvent (Xylene). Xylene from storage tank is charged into the reacting tanks by weight measurement. Technical is also weighted before charging. For safety purpose nitrogen is charged to the tank, it forms a layer at the top which reduces the

chance of fire. If the technical is in powder form then it is charged from the top inlet of the reacting tank. Liquid technical is charged from the charging sections with the air-driven diaphragm pump. Required emulsifier is charged from the charging section using the air-driven diaphragm pump. Xylene is then added.

27

During the charging the weight charged of the mixture is noticed in the control room. Now required residence time is provided to the mixture in the reacting tank and we also provide

circulation of the mixture receiving from bottom and again charging it from top. During the agitation sample is taken from the reacting tank with help of a small cylinder attached

to rod. This sample is then sent to the laboratory for its final quality test and as it is approved the batch is

then transfer to the holding tanks using centrifugal pump. Before the transfer, the batch is allowed to settle for few minutes. This settles the slug at the

bottom of tank if present. Then the slug is removed and the product is transferred to the holding tanks. Cycle time of batch

is nearly 1 hour and 30 minutes.

4.5. Production of Soluble Concentrate, Emulsion Wet and Soluble Emulsion:

The raw material (emulsifier) is preheated in hot water bath. The technical being used for EW, SC and SE is mostly in form of fine powder. Solvent required here is same as which is to be used for the product formulation e.g.

(Xylene, Reverse osmosis water). Mostly reverse osmosis water is used. All the concerned valves are now checked before the charging of the solvent. Reverse osmosis water from storage tank is charged into the reacting tanks after weight

measurement. Technical is also weighted before charging. Then the technical is chareged carefully and

slowly into the reacting tank. Required emulsifier is charged from the charging section using the air-driven diaphragm

pump. After that, balance solvent (reverse osmosis water) is added. During the charging, the weight charged of the mixture is noticed in the control room.

Required residence time is provided to the mixture in the reacting tank. The circulation pipeline involves a shearing pump, which applies shearing force to the

technical and makes the size finer and does mixing. After an hour, the shearing pump is switched off and then the mixture is circulated in

another pipe line which involves bead mill. Bead mill contains small beads which help to reduce the size and do mixing. After the size approval, slurry from another reacting tank is charged to the main reacting

tank. Then again after charging slurry the shearing pump is turned on for half an hour. Here the product is not transferred to the holding tanks but direct filling of drum is done. Cycle time of batch is nearly 1 hour and 15 minutes.

4.6. Process Flow Diagrams:

28

Figure 4.1: PFD for EC and SL formulation

29

Figure 4.2: PFD for SC, EW and SE formulation

30

4.7. Utilities for liquid formulation plant:

Furnace Heat exchanger Five reaction vessels (12,000 liters each) Four product holding vessels (20,000 liters each) One reacting vessel (1,500 liters each) Four solvent storage vessels (120,000 liters each) Two solvent storage vessels (500,000 liters each) Diaphragm pumps Strainers Side mirrors Flux well joints Bead Mills and Sheering pump

Description of above mentioned utilities is given but with the exception of common utilities;

4.7.1. Diaphragm pumps:

Diaphragm pumps are used to charge the raw material to the reacting tank. Air pressure system drives air into the bottom of the air cylinder, raising the piston inside and

lifting the diaphragm. As the diaphragm is raised, the check valve ball on the intake side is lifted and liquid flows into

the pump. When the piston has risen to the top, the pump cavity is filled and the pump is ready for

discharge. (Figure 4.3a) Compressed air is then forced into the top of the diaphragm chamber, pushing the diaphragm

down and evacuating the pump cavity. The check-valve ball on the discharge side is lifted and the pump is ready for the next cycle.

(Figure 4.3b). The pump operates at four bars.

31

Figure 4.3aFigure 4.3b

4.7.2. Strainers:

Filter provided to remove any solid particle from the outlet of the reacting tank.

It contains mesh screen which pass the fluid and stops any suspended particle present.

4.7.3. Bead Mill:

The bead mill consists of several impellers mounted on the rotating shaft. Each impeller has vanes mounted on them. The bead mill consists of small size bead or balls. These balls help to reduce the particle size and

mixing. The powder is squeezed due to the collusion with

balls.

4.7.4. Site Glass: This helps to see either the raw material is being

transferred via diaphragm pump or not.

4.7.5. Flux Well Joints:

These joints are constructed by a plastic pipe surrounded by a spiral type material and at outer most stainless steel covering is present.

Due to the spiral material its helps to control the vibration created by the diaphragm pump.

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Figure 4.4: Strainer

Figure 4.5: Bead mill

Figure 4.6: Site glass

Figure 4.7: Flux well joint

Chaper 5

33

GRANULE FORMULATION PLANT

5.1. Introduction:In 2009, the plant was established with the aim of producing insecticides in granule form. The plant is equipped with all necessary machinery and latest control instrumentations. The plant mainly consists of mixers and dryers for producing the desired product.

5.2. Capacity: Production capacity of granule formulation plant is 80,000 kg/day.

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5.3. Products: Mono mehypo hydrochloride 4% Cartap hydrochloride 4% Carbofeuron

5.4. Raw Materials:As three products are formed in this plant, so their raw materials are different.

For Mono mehypo hydrochloride 4%: Sugar Water Poly vinyl alcohol Dye Mono mehypo 5G

For Cartap hydrochloride 4%: Phosphoric acid Polyethylene glycol Cartap 4G

For Carbofeuron: Sugar Water Poly vinyl alcohol Dye Carbofeuron

5.5. Sticker solutions for Products:Sticker solution is a mixture of a different chemical compounds in proper proportion and that is used to stick the main *technical on the silica sand particles.

* Technical is a term used by most of the agri-chemical industries, particularly those industries that are directly concerned with formulation, for the main reactant involved in particular process. Here a technical means a pure compound that is needed to coat on silica sand in special proportion. e.g. carbofeuron, cartap 4 G etc.

5.5.1. Sticker Solution for Mono mehypo hydrochloride:

Poly venyl Alcohol 7%Sugar 25%Water 66.75%Dye 1.25%

5.5.2. Sticker Solution for Cartap hydrochloride:

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Polyethylene glycol 26.5%Phosphoric acid 73.5%

5.5.3. Sticker Solution for Carbofeuron:

Poly venyl Alcohol 7%Sugar 25%Water 67%Dye 1.20%

5.6. Process description:

Raw sand is introduced by the labor directly into the bucket elevator 1. Bucket elevator 1 moves the sand to the hopper 1. Hopper 1 moves sand to either rotor or dryer. Rotor (in case of monomehypo).As in the formation of monomehypo preheating of the sand is not

required. Dryer (in case of cartape).Pre heating of the sand is required. Sand is than moved to the vibrater 1 where screen used for the product size is 10-24 Mesh size.

Over size and under size product is removed and is wasted. Sand of desired size is than move to bucket elevator 2 which transports sand to the hopper 2.

Hopper 2 moves sand to the mixers connected in series. In mixers there is addition of sticker solutions for monomehypo 5G and cartape 4G respectively

along with the technical (a white colored powder of monomehypo).Sticker solutions and technical are sprayed in order to cover maximum area. Clay is also added in order to dry the material inside the mixer.

Sticker solutions are pre heated to 80 degree C and than they are used in mixers. In case of cartape 4G as preheating of the material was done so at this stage heat is not supplied

so rotor is used here. For monomehypo 5G as preheating of material was not done so heat is supplied at this stage in the dryer for 10 minutes at 100 degree C. Heat is supplied to the dryer by air which is heated by an heat exchange with steam coming from the boiler house. Steam condensate is removed from heat exchanger and is wasted.

Product is then transferred to vibrater 2 here screen used are of 10-24 Mesh size in order to remove the agglomerates which are removed and wasted.

Final product is than send to bucket elevator 3. Dust collectors are attached to all the three bucket elevators. The air used for collecting dust comes from the compressor. Bucket elevator 3 moves product to hopper 3. Hopper 3 is used as final storage Below hopper 3 there is granular filling section where granular product is filled in 7 kg bags. Bags are than send to the sealing section where seals are putted on the bags.

36

Sealed bags are than packed and sent to transportation.

5.7. Block Diagram:

Figure 5.1: Block diagram of Granule formulation plant

37

5.8. Equipment description:

Following is the list of equipments installed in granule formulation plant.

1 Type of Bucket elevator Centrifugal type2 Type of Hoppers Conical type3 Type of dryer Rotary type

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4 Type of mixers Rotary type5 Type of heat exchanger Shall and tube 6 Type of Pumps Gear pumps7 Dust collecting system Cyclone

Detailed description is given as:

Bucket elevator:

A bucket elevator or grain leg is a piece of equipment which is used to move silica sand from ground level to hoppers at some height.

A centrifugal discharge elevator may be vertical or inclined.

Vertical elevators depend entirely on the action of centrifugal force to get the material into the discharge chute and must be run at speeds relatively high.

Nearly all centrifugal discharge elevators have spaced buckets with rounded bottoms. They pick up their load from a boot, a pit, or a pile of material at the foot pulley.

The buckets can be also triangular in cross section and set close to on the belt with little or no clearance between them. This is a continuous bucket elevator. Its main use is to carry difficult materials at slow speed.

Rotary Dryers:Two rotary dryers are installed in granule formulation plant, one for drying of silica sand and other for our final product. Length of the dryer is 20 ft and its diameter is 3ft. A latest temperature controlling instrumentation system is also installed in the dryers in order to maintain our required temperature.

Construction:

The dryer is made up of large, rotating cylindrical tube, steel beams. The dryer slopes slightly so that the discharge end is lower than the material feed end in order

to convey the material through the dryer under gravity.

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Figure 5.3

Figure 5.4

Working:

Material to be dried enters the dryer, and as the dryer rotates, the material is lifted up by a series of internal fins lining the inner wall of the dryer. When the material gets high enough to roll back off the fins, it falls back down to the bottom of the dryer, passing through the hot gas stream as it falls. This gas stream can either be moving toward the discharge end from the feed end (known as co-current flow), or toward the feed end from the discharge end (known as counter-current flow). The gas stream can be made up of a mixture of air and combustion gases from a burner, in which case the dryer is called a direct heated dryer.

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Chaper 6

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Figure 5.5a: Particles movement during drying in rotary dryer

Figure 5.5b: Internal fins of rotary dryer

REFRIGERATION SYSTEM

6.1. Introduction:

Well-designed refrigeration system with good escape routes not only in the machinery room, but also in the vicinity of air coolers, is installed in order to cool brine solution up to -40 oC. Four compressors are used for the refrigeration of brine, two are single stage and other two are double stage compressors.

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Temperature of -15oC (of brine solution) is achieved by following single stage refrigeration Temperature of -40oC (of brine solution) is achieved by following double stage refrigeration

cycle.

Ammonia is used as a refrigerant. Ammonia is inherently more efficient than halocarbon refrigerants because of its high latent heat, its high critical temperature and its low molecular weight.

6.2. Steps in Refrigeration Cycle:

The compressor in the refrigerator compresses the ammonia gas (the refrigerant). The compressed gas heats up as it undergoes pressurization.

The induced draft cooling tower let the hot ammonia gas dissipate its heat and thus the hot ammonia gas condenses into liquid ammonia at high pressure.

The high-pressure ammonia liquid flows through the expansion valve. The expansion valve is just like a small hole. One side of the hole contains high-pressure ammonia liquid and the other side is a low-pressure area because the compressor is sucking gas out of that side.

The liquid ammonia evaporates immediately in brine box as its temperature drops. In fact heat is transferred between brine and ammonia.

Saturated refrigerant vapor is usually superheated to ensure that liquid refrigerant does not flow into the compressor.

The compressor sucks up the cold ammonia gas and thus the cycle keeps on repeating itself, maintaining a constant cold temperature inside the brine box.

The following refrigeration processes occur during the operation of Ammonia gas expansion refrigeration system:

Compression. Air or gas is compressed to a higher pressure and temperature. Heat release. Heat is released to the surroundings at constant pressure in order to reduce the

temperature of the air or gas. Throttling and expansion. Air or gas is throttled and expanded so that its temperature is lowered. Heat absorption. Heat is absorbed from the surroundings because of the lower air or gas

temperature.

6.3. Block Diagrams:

1. Single Stage Refrigeration Cycle:

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2. Double Stage Refrigeration Cycle:

6.4. Process Flow Diagram:

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Figure 6.2: Double Stage Refrigeration Cycle

Figure 6.1: Single Stage Refrigeration Cycle

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Figure 6.3: PFD of Refrigeration Cycle

6.5. Equipment Description:

The main equipments used in refrigeration system are; Compressor Oil Separator Condenser High pressurized ammonia container (Receiver) Throttling Devices Evaporator Inter Cooler Air separator Accumulator for vapor/liquid ammonia separation

The detailed explanation of mall equipments is given bellow:

6.5.1. Compressor:

The refrigeration compressor is the heart of the refrigeration system. It removes the vapor from the evaporator and introduces vapor to the high-pressure side of the systems. It maintains the low-side pressure at which the refrigerant evaporates, and the high-side pressure at which it condenses. In brief, it supplies the pressure differences necessary to keep the system refrigerant flowing through the system

Two compressors are used here for compressing ammonia.6.5.1.1. Single acting Compressor :

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Figure 6.4: Piston type compressor

It has single suction and discharge. It consists of piston and cylinder assembly, which compresses the ammonia The water circulation is applied so as to make it cool during working. High power and compression unit. Oil lubrication is also present to make it work smooth.

6.5.1.2. Double acting Compressor: It has two suctions and discharges that allow it to perform double compressing action

using inter cooler. It consists of piston and cylinder assembly, which compresses the ammonia The water circulation is applied so as to make it cool during working High power and compression then single unit Oil lubrication is also present to make it work smooth

6.5.2. High pressurized ammonia container (Receiver): High pressurized ammonia containerserves as a buffer for liquid ammonia to be stored

for use by the system. The liquid ammonia is taken from the receiver to the evaporators as needed to satisfy the

load. A receiver is needed when the system refrigeration load varies greatly. It consists of pressure relief valve so as to overcome any accident.

6.5.3. Evaporator: Inside the evaporator heat from the cooled region or medium is absorbed into the

refrigerant, as a result, the refrigerant changes from a liquid to a vapor. In a given refrigeration system, Coil type heat exchangers are used to chill the brine solution.

6.5.4. Accumulator: It is used to store the ammonia vapors that are coming from the brine box or evaporator. The purpose of accumulator is to remove the ammonia liquid from the vapors if they

present. . If the gas is directly send to the compressor it may damage it because of presence of

liquid.

6.5.5. Condenser: The condenser transfers the heat from the refrigerant to a coolant medium, usually

ambient air.

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Inside the condenser the refrigerant changes from a vapor to a liquid. There are three basic types of condensers:

o Air-cooled

o Water-cooled

o Evaporative

The condenser installed in the given is evaporative type.

An evaporative condenser is a combination of an air-cooled and a water-cooled condenser. As the hot refrigerant vapor flows though the bank of tubes, water is sprayed over the tubes and evaporates. As the water evaporates, it absorbs heat from the refrigerant, which increases the efficiency of the condensation. Because of the increased efficiency, evaporative condensers can be smaller than air-cooled units.

6.5.6. Throttling Devices:

The throttling device separates the high-pressure and low-pressure sides of the system. It reduces the refrigerant pressure and controls the flow rate of refrigerant to the

evaporator in systems. The following are types of throttling devices:

o thermostatic expansion valve

o constant pressure expansion valve

o float valves

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Figure 6.5: Evaporating type Condenser

6.5.7. Oil Separator:

Oil has a very important effect on the efficiency of ammonia systems, especially when it gets into the evaporator. When the oil adheres to the tubes in the evaporatoror condenser, it forms film that reduces the rate of heat transfer.

Oil separator is used to separate the oil or lubricant from the refrigerant. It consists of plates on which the gas strikes and oil particles are removed The oil is then drained from the bottom Oil separators installed in a given refrigeration system can achieve high efficiencies with

carryover rates of less than 10 ppm.

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Figure 6.7: Oil Separator

Figure 6.6: Throttling Valves Assembly

6.5.8. Air Separator:

It consists of small grooves on which air strike and condenses The condense air is then form immiscible layer with liquid ammonia and thus is removed The whole of the assembly is compact in packing

6.5.9. Inter Cooler: Inter cooler is used when refrigeration is done by using two stage compressor.

Intercooling affects the overall efficiency of the machine. It is a heat exchanger that removes the heat of compression between the stages of

compression.

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Figure 6.9: Inter Cooler

Figure 6.8: Air Separator

Chaper 7

BOILER HOUSE

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7.1. Introduction:

There are two boilers installed in Pak China Chemicals Ltd. The main purpose of boilers is to produce steam. The generated steam is given to all running plants e.g. Formulation plant, Granule formulation plant, PCM Plant according to their requirement. The steam pressure for every plant is different according to their requirement as mentioned above.

7.2. Boiler Description:

Two firetube boilers are installed that consist of a series of straight tubes that are housed inside a water-filled outer shell. The tubes are arranged so that hot combustion gases flow through the tubes. As the hot gases flow through the tubes, they heat the water surrounding the tubes. The water is confined by the outer shell of boiler. These boilers have cylindrical outer shells with a small round combustion chamber located inside the bottom of the shell.

Further description is given in the following table.

Type of boiler Fire tube Boiler

Type of fuel Diesel

Inner sheet of boiler Stainless steel

Outer sheet of boiler Mild steel

Insulation of boiler Glass wool

Maximum pressure of steam 9 bar

Maximum temperature of steam 270oC

Number of tubes 42

Diameter of each tube 2.5 inch

Length of each tube 10 ft

Capacity of boiler 2ton of steam/hr

Flue gases temperature 100-110oCTable: 7.1

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Figure 7.1: Fire tube boiler at Pak China Chemicals ltd.

7.3. Process Flow Diagram for Boiler House:

Figure 7.2: PFD for boiler house

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7.4. Water Softener:

It consists of zeolite bed, which removes salt contents from the water Up to 6ppm of the salt content is reduced here The resulting water is known as soft water This water minimizes scaling in the boiler With passage of time, they are also regenerated

7.5. Boiler Maintenance:Corrosion avoiding: In order to avoid corrosion in boiler, oxygen in feed is reduced by sodium sulphite.

Acid cleaning: For washing boilers, acid cleaning is done. In Pak China Chemicals, acid cleaning is done by using dilute sulfuric acid.

Silicate removal from walls: For removing silicates, 5-10% soda ash is introduced and water is boiled. It removes silicates from boiler wall and also neutralizes the effect of acid.

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Figure 7.3: Water softener

Chaper 8

PLANT SAFTEY AT PAK CHINA CHEMICALS

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8.1. Introduction:

The significance of Safety & Health in chemical industries has been a vital issue in achieving productivity and an edge in the competitive world. As Pak China Chemicals formulates most of the organic compounds for the production of pesticides and insecticides. Being organic, these compounds are highly explosives and flammable. They can cause severe action when inhaled for even more then 2 minutes. So, in order to avoid any danger, necessary safety system is installed.

8.2. Facts of safety & health in a chemical industry:

Risk of accident: Areas of Concern:

Dangerous Materials Hazards of Pressure Vessels Hazardous Chemical Reactions Hazardous of Unit Operations Flammable Gases, Vapors And Dust Hazards Sampling and Gauging Hazards due to Instrument Failures.

Dangerous Materials:

Explosives Gases Inflammable Liquids Inflammable Solids Oxidizing substances Toxic and Infectious substances

Hazards of Pressure Vessels:

Leakage or Bursting of Pressure Vessels Design defects Failure of Relief Systems Lack of Proper Instrumentation or Instrumentation Failure Lack of routine inspections

8.3. Protection zones (explosion protection, separation distances):

Premises are strictly maintained as a “No Smoking” area. For electrical installations and instrumentation, the entire plant area has been sub-divided into hazardous and non hazardous zones. The hazardous zones have been lassified appropriately as per the National Fire Protection Association (NFPA) code 70, better known as the National Electric Code. The NFPA classifies Hazardous Areas by three different factors known as classes, groups and divisions. These factors each identify different elements of concern and combine to define the type of hazardous

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substance (Class), and explosive rating of the substance (Group) and the degree of hazard created (Division).

The plant layout has been designed as per established engineering practices in conformity with the provisions of required safety separation distances have been maintained. The layout of plants, under the purview of the various statutory regulations has been granted and these regulations are being renewed regularly.

In addition to the fulfillment of statutory requirements, compliance of recommendations of various other national and international standards and Code of Practices has been kept in view for the layout of the plant facilities. Separation distance maintained in protection zones as per rules. The equipments, pipings and instruments action are provided for explosion protection. Explosion proof motors and fittings are used for hazardous areas.

Explosive meters are also provided to plant in-charges for checking gas leak, if any. Proper fire prevention and protection equipments installed, checked and kept ready.

8.4. Setup of fire and safety at Pak China Chemical Plant:

All staff of Fire & Safety, Health and Environment sections is well qualified Engineers, Fire& safety officers and Doctors.

Equipments for Fire Fighting:

Pak China Chemical plant is well equipped with all Fire & Safety appliances like Fire Tenders-3 with a pick up van, all types of extinguishers like DCP, CO2, WATER CO2 Foam types in adequate number.

Fire Alarm System for Plant Control Rooms, Administrative building, Cable Galleries, Transformers are also provided. These are of Ionization, Optical & Heat sensing type.

Fixed Installations: All Xylene tanks are protected by installation of automatic fixed foam pouring system at their top

which is checked periodically and record is maintained. Smoke detection system is provided at all the important buildings and control rooms. Well Laid underground Fire Hydrant System, underground fire hydrant pipes has been laid

throughout the premises.

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References:

1. J.f Rechardson, J.H Herker, J.R Backhurst, Chemical Engineering, Ed. 2002. P.919-9252. Electronic source: http://www.aliakbargroup.com

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