dscl kota

A

REPORT

ON

INDUSTRIAL TRAINING

AT

SHRI RAM FERTILIZERS & CHEMICALS LIMITED, KOTA

IN

PVC PLANT

DURATION:- 22/06/2011 to 22/07/2011

SUBMITTED TO: - SUBMITTED BY:-

Mr. V.S. TATERH VED PRAKASH SAHU

HEAD OF PVC PLANT CHEMICAL ENGINEERING

2nd Year

IIT-GANDHINAGAR

PREFACE

Private sector is one of the fastest growing sectors in the country. After the Liberalization,

private sector started to spread and grow at much faster rate and dominated many sectors.

The Private industry holds vast opportunities for young and experienced professionals.

Industrial training is the best way to come in touch with the company. For a chemical

engineer it is important to get practical knowledge and understand process of plant that

helps in future.

While undergoing industrial training at DSCL KOTA in PVC plant I learned a lot of practical

aspect.

It was a great experience to know the working of the plant and to know the technology used

here. I visited the whole plant and got lot of guidance from experienced persons.

ACKNOWLEDGEMENT

For successful completion of any job one needs help and cooperation from person involved directly or indirectly to the organization.

It was great opportunity to get training at such esteemed organization. It is one of my memorable experiences being here for 30 days interacting with people of various fields.

I am thankful to Mr. Inder Kundnani for giving me permission and facilities to work at organization.

Further I am thankful to Mr. V. S. Taterh, who guided me and provided facilities in the plant.

I would like to thank Mr. SU Puranik, Mr. Ashok Adlakha, Mr. J. C. Chittora, and Mr. Ravindra Pipliwal for their support and guidance.

I will always remember guidance of Mr.Anuj Mehrotra in Vinyl chloride monomer plant.

INDEX

1. Company profile

1.1 Company Business

2. PVC

2.1 Introduction

2.2 Type of polymerisation used

2.3 Raw Materials

3. Process in Monomer section

3.1 Stripping of HCI

3.2 Acetylene dehumidification and drying.

3.3 Mixing Tank

3.4 Synthesis of VCM

3.5 Removal of HCI

3.6 VCM dehumidification

3.7 VCM rectification

3.8 Recovery of acetylene

4. Process in polymer section

4.1 Reactors

4.1.1 KF (Kanega Fuchi) reactor

4.1.2 CHISSO reactor

4.2 Reactor process

4.3 Recovery of VCM

5. Dry and Packing section

6. Products and their applications

7. PVC Laboratory

8. Suggestions

9. Project Problem

1. Company Profile

1.1COMPANY BUSINESSES

The main businesses units of DSCL now comprise of:

Agri Businesses Energy Intensive Businesses

Value Added Businesses

Other Businesses

Sugar Chemicals Fenesta Building Systems

Textiles

Urea PVC Resins PVC CompoundsAgri Inputs Cement Energy ServicesShriramBioseedsHariyaliKisaan Bazaar

1. Sugar Sugar is a key component of DSCL agri-business portfolio. Sugar operations

functioned as an independent company within our Group until March 2004 when they were merged in DSCL.

DSCL now have a combined installed capacity of 33,000 TCD (tonnes crushed daily) and a power generating capacity of 94.5 MW, with an exportable surplus of 51.5 MW for the grid. Sugar plants are self-sufficient and also export power to the UP state grid.

2. Farm Solutions DSCL’s Farm Solutions Business is engaged in providing comprehensive solutions to

the Indian farmer. The business makes a range of fertilizers, crop care chemicals, seeds and customized agronomy advisory services available to the farmer through a distribution

network comprising of over 1500 wholesalers and over 20000 retailers.

3. Urea DSCL is amongst the first “urea” manufacturers in the country starting way back in

the 1960's.Their fertiliser operations are characterized by highly optimized production process delivering high capacity utilization & proven abilities in erection, commissioning, operation& troubleshooting of Ammonia/Urea plant.

Meanwhile, the Company has started running the plant on gas from Sep ’07 onwards.This will further reduce cost of production.

4. Hybrid Seeds DSCL offers a range of hybrid seeds in the country via its brand ShriramBioseed .

The Company also operates its seeds business in Vietnam, Philippines and Thailand and proposes to expand to other locations in Asia Pacific region. At present, the Company deals in Corn, Bajra( Pearl Millet), Jowar, Paddy, BT Cotton, Vegetables and Sunflower seeds.

5. HariyaliKisaan Bazaar "HariyaliKisaan Bazaar" - a rural business centre, is a pioneering micro level effort,

which is creating a far-reaching positive impact in bringing a qualitative change and revolutionizing the farming sector in India.

DCM Shriram Consolidated Ltd. (DSCL), capitalising its over 35 years of experience

in the agri-input markets & first-hand knowledge of Indian farmers, is setting up a chain

of centres aimed at providing end-to-end ground level support to the Indian farmer & thereby improving his "profitability" & "productivity".

6. Castic Soda Caustic Soda is a basic product very widely used in diverse industrial sectors, either

as a raw material or as an auxiliary chemical. As mentioned earlier, it is produced along with chlorine. It is mainly used in the manufacture of pulp and paper, newsprint, viscose yarn, staple fiber, Aluminum, cotton, textiles, toilet and laundry soaps, detergents, dyestuffs, drugs and pharmaceuticals, vanaspati, petroleum refining. Caustic soda is produced in two forms - lye and solids. Solids can be in the form of flakes or granules.

7. Chlorine Chlorine is co-produced with caustic soda in the electrolysis of brine. For every ton of

caustic soda produced, 0.886 tons of chlorine is also produced. Being a gas and also due to its hazardous nature it cannot be transported over long distances. Generally chlorine is liquefied and transferred into 0.9 metric ton cylinders (called tonners) which are then

transported over a limited geographical radius.

8. PVC Resins DSCL manufactures multiple grades of PVC resins covering a wide array of end-use

markets. The PVC resins produced by Company are renowned for their quality and reliability offering the distinct benefits of a low fish-eye count and uniform particle size. .

The Company has a 70,000 TPA (after the recent expansion), PVC resins facility at its integrated manufacturing complex at Kota, Rajasthan.

The Company utilises the calcium carbide route to produce PVC resins whereas all other manufacturers use the ethylene/EC/VCM route. Chlorine and calcium carbide, the two key inputs in the manufacture of PVC resins are produced by the Company at the integrated manufacturing complex itself. After catering to captive consumption, DSCL sells the calcium carbide to other companies in the chemicals and steel industry. Also, the Company further processes the waste sludge produced during the manufacture of calcium

carbide to make cement. Of the PVC resins made, the Company is able to consume between 20-25% through its PVC Compounding division, selling the rest to other manufacturers and compounders.

9. Calcium Carbide Calcium carbide (CaC2) is manufactured by mixture of lime and carbon in electric

furnace.

The company has enhanced its manufacturing capacity of Calcium carbide from 66,500 TPA to 1, 08,500 TPA by commissioning its state of the art 30 MVA electric furnace in July 2005. The company utilises its Calcium carbide captively for the

manufacture of PVC resins and also sells in the market to the various industrial users.

10. Cement DSCL’s cement business allows to create wealth from waste generated from its

calcium carbide plant. DSCL is the only manufacturer in the country that converts waste into consistent quality, premium grade cement.

11. PVC Compounds DSCL is one of the largest organized player for PVC compounds and has its

manufacturing facility based at Kota. The compounding facility sources its requirement from the PVC resin plant. The Company at present has a compounding facility of 23,400 MT. DSCL has also set up Innovative Polymer Application Center (i-PAC) to undertake research and development activities in various application areas and develop new and innovative high end value added products.

12. Textiles The textile group comprising of Swatantra Bharat Mills and DCM Silk Mills earlier

situated in 112 acres of prime land in the heart of Delhi has relocated to Tonk, Rajasthan. Pursuant to the relocation, the modern facility at Tonk is operating successfully.

The Company has sold the said prime land in August 2007.

2.PVC

2.1INTRODUCTION

Polyvinyl chloride, (IUPAC Poly (chloroethanediyl)) polymer of vinyl chloride is commonly abbreviated PVC, is the third most widely used thermoplastic polymer after polyethylene and polypropylene. In terms of revenue generated, it is one of the most valuable products of the chemical industry. Around the world, over 50% of PVC manufactured is used in construction. As a building material, PVC is cheap, durable, and easy to assemble. The PVC world market grew with an average rate of approximately 5% in the last years and will probably reach a volume of 40 million tons by the year 2016.

It can be made softer and more flexible by the addition of plasticizers, the most widely-used being phthalates. In this form, it is used in clothing and upholstery, and to make flexible hoses and tubing, flooring, to roofing membranes, and electrical cable insulation. It is also commonly used in figurines and in inflatable products such as waterbeds, pool toys, and Inflatable structures.

Properties:-

Density 1390 kg/m3

Young's modulus (E) 2900-3300 MPa

Tensile strength(σt) 50-80 MPa

Elongation at break 20-40%

Notch test 2-5 kJ/m²

Glass temperature 82 °C

Melting point 100–260 °C

Vicat B 85 °C

Heat transfer coefficient (λ) 0.16 W/(m·K)

Effective heat of combustion 17.95 MJ/kg

Linear expansion coefficient (α) 8 x10-5/K

Specific heat (c) 0.9 kJ/(kg·K)

Water absorption (ASTM) 0.04-0.4

Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer (VCM). Since about 57% of its mass is chlorine, creating a given mass of PVC requires less petroleum than many other polymers.

2.2 Type of polymerisation used

Here we use suspension polymerization techniques with suspending agent polyvinyl alcohol.

2.3 Raw Materials

1.HCl acid:-

Hydrochloric acid is the solution of hydrogen chloride (HCl) in water. It is a highly corrosive, strong mineral acid and has major industrial uses. A 30% HCL solution from caustic soda plant is used as raw material.

Chemical properties:-

1.Molecular formula- HCl in water (H2O)

2.Molar mass-36.46 g/mol (HCl)

3.Solubility in water-miscible

Hydrochloric acid as the binary (two-component) mixture of HCl and H2O has a constant-boiling azeotrope at 20.2% HCl and 108.6 °C (227 °F).

2.Acetylene :-

Acetylene (IUPAC name: ethyne) is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colourless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.

As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond. The carbon-carbon triple bond places all four atoms in the same straight line, with C-C and C-H bond angles of 180°.

3.HgCl2 (Mercury (II) chloride)

Mercury (II) chloride or mercuric chloride (formerly corrosive sublimate), is the chemical compound with the formula HgCl2. This white crystalline solid is a laboratory reagent. It was formerly used more widely however it is one of the most toxic forms of mercury because it is more soluble than most other forms in water.

Properties:-

Molecular formula HgCl2

Molar mass 271.52 g/mol

Appearance white solid

Density 5.43 g/cm3

Melting point 276 °C, 549 K, 529 °F

Boiling point 304 °C, 577 K, 579 °F

Solubility in water 7.4 g/100 ml (20 °C)

Solubility soluble in alcohol, ether, acetone, ethyl acetate slightly soluble in benzene, CS2

Acidity (pKa) 3.2 (0.2M solution)

Crystal structure Orthogonal

Dipole moment Zero

4.Brine Solution(CaCl2.6H2O solution)

Introduction of CaCl2:-

Calcium chloride, CaCl2, is a common salt. It behaves as a typical ionic halide, and is solid at room temperature. It has several common applications such as brine for refrigeration plants, ice and dust control on roads, and in concrete. It can be produced directly from limestone, but large amounts are also produced as a by-product of the Solvay process. Because of its hygroscopic nature, it must be kept in tightly-sealed containers. Aqueous calcium chloride (in solution with water) lowers the freezing point as low as -52°C (-62°F), making it ideal for cooling .Here we use solution of CaCl2.6H2O with specific gravity of 1.2.

5. Sodium Hydroxide (NaOH)

Sodium hydroxide(Na OH ), also known as lye and caustic soda, is a caustic metallic base. Sodium hydroxide forms a strong alkaline solution when dissolved in a solvent such as water, however, only the hydroxide ion is basic. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around 45 million tonnes. Sodium hydroxide is a common base in chemical laboratories.

6.Toluene

Toluene, also known as methylbenzene, phenylmethane, and Toluol, is a clear water-insoluble liquid with the typical smell of paint thinners, redolent of the sweet smell of the related compound benzene. It is an aromatic hydrocarbon that is widely used as an industrial feedstock and as a solvent. Like other solvents, toluene is also used as an inhalant drug for its intoxicating properties; however this causes severe neurological harm.

Properties:-

Molecular formula C7H8 (C6H5CH3)

Molar mass 92.14 g/mol

Appearance colorless liquid

Density 0.8669 g/mL

Melting point −93 °C

Boiling point 110.6 °C

Solubility in water 0.47 g/l (20–25°C)

Viscosity 0.590 at 20°C

7.Water (H2O)

Water is the chemical substance with chemical formula H2O: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom.Water is a tasteless, odourless liquid at standard temperature and pressure.

8.Ammonia gas

Ammonia is a compound of nitrogen and hydrogen with the formula NH3. It is normally encountered as a gas with a characteristic pungent odour.

3. Process in Monomer section

The process starts with two raw materials 30% (w/w)HCl acid coming from caustic soda plant and Acetylene gas coming from carbide plant. Acetylene gas also has some inerts. For the reaction between HCl gas and Acetylene gas we need dry gases because moisture acts as a poison to the catalyst (HgCl2).

3.1 STRIPPING OF HCL

Here we strip HCl from 30% HCL solution by using a stripping section. It starts from HCl storage tank.

HCl storage tank:-

Hydrochloric acid is a corrosive product. In contact with some metals, hydrochloric acid releases hydrogen (flammable). It is normally stored in lined steel or certain types of plastic materials.In this plant, the storage tanks are horizontal cylindrical tank. They are made of mild steel and rubber coating inside because HCl is very corrosive. In these tanks, 20% and 30% HCL is stored of which 30% HCL is used in vinyl chloride monomer plant and 20% HCL is sent to chlor alkali plant.

HCl stripping section:-

HCl acid (30%) is supplied from caustic soda plant act as a raw material for this section. HCl is fed to preheater from the bottom and then it gets heated. It is then sent to the stripper column.

HCl stripper column consists of carbon rasching ring, which are randomly distributed. The stripper is made of graphite because HCl is highly corrosive .We cannot use mild steel. In this we shower the HCl acid from the top on carbon rings.

Reboiler is a shell and tube heat exchanger. In reboiler, steam flows in shell side and HCl acid flows inside the tube and is heated by the steam to vaporise.

HCl acid is fed to the stripping columns from the top. As it comes down it comes in contact with the HCl gas coming from reboiler from the middle of stripper and gets heated. Due to heating it gets separated into two fractions i.e. HCl gas and 20% HCl solution. As this HCl gas moves upwards it strips 30% HCl which is being fed from the top of the column. Separation finally gives 20% HCl and 30% HCl.

Steam is used to evaporate the HCl solution coming in reboiler. Temperature at the top of the stripper is maintained to about 95⁰C.

The level regulator present ensures that the 20% HCl does not exceed a particular level in the stripper. So it removes the liquid above level. This 20% HCl is at a high temperature so it is again sent to the preheater where it is used to heat the 30% HCl by passing it in the jacket of preheater. 20% HCl coming out of the preheater is then again cooled and is sent to the 20% HCl tank. The pure HCl is the top product and is passed through two water coolers and two brine coolers and mist separator to remove the left over moisture in the gas. The gas coming out of the stripper is at about 92⁰C. After this gas is sent to the buffer tank out let of which is about 18⁰C.Then the two gases i.e. hydrogen chloride and acetylene is fed to the mixing tank.

3.2Acetylene dehumidification and drying

ACETYLENE DEHUMIDIFIER

Acetylene used for VCM synthesis is supplied from carbide plant, at 55 ⁰C .It is saturated with water vapours at this temperature. For VCM synthesis acetylene needs to be completely dry and therefore it needs to be dehumidified.

For dehumidification acetylene is fed to the bottom of the dehumidifier and chilled brine solution is sprayed from top. On coming in contact with acetylene, brine solution condenses moisture from acetylene. Dehumidifier consists of ceramic saddles and along the height of this column trays are present to equalize the distribution of brine coming from top varies from -4⁰C to 0⁰C.

Dehumidified acetylene is removed from the top of tower and the brine solution removed from the bottom is sent to the brine cooling where it gets cooled again and can be again fed to the dehumidifier. The brine which is used in the cooler to cool this brine is coming about -13.3⁰C and going at-8.6⁰C.

Brine which is being sprayed from the top is at about -4⁰C and the brine outlet from the dehumidifier is at 0⁰C.

Acetylene coming from dehumidifier is fed to the dryers filled with solid lumps of CaCl₂.6H₂O, the moisture is removed and then dried gas is passed to the mixing tank. The gas coming out of the dryer is at about 20⁰C.

3.3Mixing Tank

HCl from the buffer tank and the acetylene coming from the dryer are fed into the mixing tank in the molar ratio 1.1:1. A 10% excess of HCl is used to enable complete conversion of acetylene as it is very costly. The gases should be in perfectly dry state as presence of moisture leads to corrosion in presence of acid. The mixing tank consists of horizontal plates and the gaseous mixture of HCl and acetylene is fed from the bottom. Thus as the mixture moves upwards it is much more uniform and thus helps in increasing the effectiveness of the reaction in the reactor.

3.4 Synthesis of VCM

The mixture of gases is then fed to tubular reactors which are basically heat exchangers. These reactors consist of a vessel having an inverted cone like bottom. It has 944 tubes in

which the catalyst HgCl2 impregnated on activated carbon is fed. The cone shaped design at the bottom ensures uniform flow of reacting gases in the mixture thus leading to an efficient reaction.

C₂H₂+ HCl CH₂=CH-Cl+95.5 KJ/mole

The reaction is highly exothermic and temperature has to be maintained between 90-100⁰C since the catalyst has the tendency to sublimate at higher temperature. To maintain the temperature of the reaction at about 90-100⁰C, a solution of NaOH is passed in shell side of the reactor, shell side is made of MS. Here we don’t use water because water boils earlier as compared to NaOH and thus it will form steam which may result in the shaking of the reactor. The NaOH coming out of the reactor is cooled and again circulated in the shell side of the reactor. The temperature of NaOH is maintained by passing it through another shell and tube heat exchanger in which water is flowing in the tube side. About 80-85% conversion takes place in the reactor. The gas coming out of the reactor is at about 90⁰C.The gas coming out of the reactor is VCM with some amount of HCl and acetylene and side product, dust of carbon. Then the gas is sent to the dust separator which is a cyclone separator.

Dust separators are used to remove carbon particles that may come along with the product stream.

3.5 Removal of HCl

After synthesis in the reactors, VCM consists of impurities like unreacted HCl, acetylene and inert materials. Thus it is necessary to purify VCM. VCM is passed through scrubber for removal of unreacted HCl. VCM enters from bottom and water is sprayed from the top. Since HCl is soluble in water, as VCM moves up HCl gets dissolved in water. This water is drained at the bottom of the scrubber. This drained water is a 1-2% HCl solution. This 2% HCl is sent back to carbide plant. Temperature of the scrubber is maintained at about 35⁰C. After passing through scrubber it is passed through VCM deacidifier. Here the gas comes in contact with NaOH solution which neutralizes remaining HCl. This ensures complete removal of HCl. VCM is then stored in gas holder.

GAS HOLDER:This gas holder is floating head gas holder here the pressure of VCM is stablized to 330 mm H₂O.

The three main reasons of doing this:-

1. Increases the compressor life

2. To prevent pressure from increasing very high

3. To maintain lowest pressure in the whole plant so as to help in recovery of gas back to gas holder.

3.6VCM DEHUMIDIFICATIONSince the gas passes through water in the gas holder thus gas in the holder consists of some amount of moisture in it. Then it is sent to the dehumidifier to remove this little amount of moisture. In this dehumidifier chilled caustic solution is sprayed from the top while the gas enters from bottom.

The NaOH solution is fed to the column at about 3⁰C .When NaOH comes in contact with the water, it absorbs moisture and dehumidified VCM can be removed from the top. Now the gas is fed to the VC dryers where the gas is passed through lumps of NaOH which absorbs the left over moisture in the gas. Now after removal of moisture, the gas is sent to the compressor. The temperature of caustic is lowered by chilled brine which is obtained from the utility section where its cooling is carried out.

3.7 VCM RECTIFICATIONAfter removal of HCl gas and moisture, VCM still has unreacted acetylene and some other inert as impurities, these are removed by rectification. First of all VC is compressed in compressor and then passed through oil separator to remove the oil which may come along with compressed VC .

The temperature of VC after coming out of oil separator is about 48⁰C.The compressed VC is then passed through condensers. In these condensers almost 90% VC is condensed because of the difference in boiling point of two liquids.VC has BP of 259 K and acetylene has BP of 119 K.The uncondensed part is sent to the purge gas condenser. The condensed part of VC is sent to first tower.

The top product of the first distillation tower is rich in acetylene. It is then passed through partial condenser which condenses the VC present in it and this condensed VC is sent back as reflux to the first tower and the uncondensed part is sent to the purge gas condenser.

The bottom product of first tower consists mainly of VC and high boilers which are sent to the bottom tank 1.The pressure of first distillation tower equals that of the bottom tank. The liquid VC flows into the second tower where the pressure is kept low as compared to the bottom tank or the first tower. Thus no extra pump is required to pump liquid VC to the second tower.

The design of tower is such that it contains plates having bubble caps. The feed from condenser is given to intermediate plate. The vapours of VC rise up and as soon as they come in contact with the bubble cap they condense to form liquid VC. Thus only liquid VC is collected at the bottom.

The second tower is used for the purification of VC. The design of the second tower is same as that of the first tower. The feed to the second distillation tower comes from the bottom tank 1 and also comes from V-666 storage tanks (Recovered from PVC reactor) where VC is recovered.

Tower 1 Tower 2

Here after distillation the top product is VC which is sent to the total condensers where it gets condensed. Some portion of condensed VC is sent to the tower as reflux and remaining to the storage tanks. Temperature of the liquid VC in the storage tank is about 33⁰C.

3.8 RECOVERY OF ACETYLENE

The uncondensed portion from the purge gas condenser consists mainly of acetylene and some inert. It is fed to the recovery tower in which chilled toluene is sprayed from the top. This toluene is at a temperature of about -3⁰C.The chilled toluene absorbs acetylene and is removed from the bottom. This liquid is used to precool the toluene coming from the solvent tank. Here the conditions which favour the absorption are low temperature and high pressure. It is then sent to the solvent tank. Solvent tank is jacketed with hot water being circulated in the jacket. Here the conditions which support desorption are high temperature and low pressure. On heating to about 30⁰C toluene liberates acetylene and the liberated toluene is sent to the precooler where it is cooled by the chilled mixture of toluene and acetylene coming from the recovery tank and flowing in the shell side. It is then sent to the brine cooler and is again used for showering in the recovery tank. The acetylene is then sent to the mixing tank. The top products of recovery which are inert are exhausted.

4. Process in Polymer Section

4.1 REACTORS

VCM formed in monomer section is used to produce PVC of varied types in reactors by suspension polymerization technique. Polymer has two different type of reactors namely KF and CHISSO. There are two KF reactors and one CHISSO reactor, both are commissioned by Japanese.

4.1.1 KF(Kaunga Fuchi) Reactor

Each reactor has a capacity of 80 m3. Reactor is a agitated jacket vessel, with agitator kept vertically sealed at top and

fixed at bottom of the vessel with a bearing. Cycle time is about 12.5 hrs and reaction time is about 9 hrs. Percadox is used as catalyst (initiator) in powdered form. 80-85% conversion takes place.

4.1.2 CHISSO Reactor

Each reactor has a capacity of 100 m3. It is also a agitated jacket vessel, with agitator sealed with vessel from bottom and

other end free. The top of the reactor has a condenser known as Reflux condenser to condense VC that gets vaporised.

Cycle time is about 9 hrs and reaction time is about 6 hrs. Tregnox in liquid form is used as the catalyst. Due to less half life it increases reaction

rate. Conversion is 90- 95%.

4.2 REACTOR PROCESS

Hot water is circulated in the jacket of the reactor then applies Noxol coating on the interior of the vessel. Noxol is an anti-coating agent. Raw materials are then charged into the reaction vessel.

The raw materials are VCM liquid, hot pure water, polyvinyl alcohol as suspending agent and catalyst as reaction initiator. Additive chemicals are used for heat stability and other for quality maintenance.

It is a free radical reaction with three steps, namely initiation, propagation and termination.

Agitator is used to mix the contents of the vessel uniformly. Since the reaction is exothermic, the reaction temperature is maintained by circulating cold water in the jacket of reactor. Baffles are used for turbulence and heat transfer.

The seal of the reactors is specially made to prevent any leakage of VC , since it a hazardous gas and can explode, leading to catastrophic damages. The seal used is also called oil seal because it mechanism is such that oil starts to pour inside the reactor if the seal fails and thus preventing any damage that can be caused.

Most of the conversion takes place during the reaction time, after that the reaction is too slow and to increase efficiency and save power, on fix ΔP we transfer to stripping tank to recover rest of VCM and material in form of slurry.

4.3 RECOVERY OF VCM

After completion of reaction, the product contains PVC slurry (PVC Resin and water) and VCM liquid.

Recovery of VCM

After stripping tank, the products are sent to DMT, which is a storage tank from which some VC gets vaporised. From DMT, the products are pumped into RVCM tower from top and steam is passed from bottom of the tower. The tower is in the shape of stripping column in which steam provides heat for vaporisation of VC, which moves out from top of the tower.

Slurry (PVC and water) is recovered from bottom of the tower and is pumped to Wet PVC tank.

5.DRYING AND PACKING SECTION

Slurry from wet PVC tank is sent to dryers to remove water and moisture to get PVC resin, which is then packed for sale.

There are two dryers for KF called F/F (Flash and Fluid) dryers and CHISSO dryer for CHISSO.

6. PRODUCTS AND THEIR APPLICATIONS

SR-07 SR-08 SR-10A SR-10AA SR-13ARigid transparent films

Injection moulded articles

Footwear False Roofing Medical grade sheathing

Bottles Sheets Wire and Cables High rating cables

Fittings

Floor Tiles Antistic floor tiles

Blood Bags Electrical duct Insulation

Pipe Fitting Rigid flexible films

Moulding Windows frame Wire and cable sheathing

7. PVC Laboratory

1. Impurities in PVC resin is checked at packing site by visual inspection.

2. Size distribution of PVC resin formed is checked by passing the resin through net of different sizes.

3. K value test: is done to check the degree of polymerization and hence the type of PVC resin formed and whether it matches the theoretical product expected.

K value is the measure of relative volatility of given PVC resin solution in cyclohexane w.r.t. pure cyclohexane.

4. VCM reactor Conversion Test: it is done to find the % conversion of HCL and Acetylene into VCM in different reactors. Sample of product is taken from every reactor. A given sample is passed through 10% KOH solution, which absorbs HCL present in the sample. Now

100ml of sample is filled into the apparatus and is passed through ammonical cupreous chloride solution, which leads to precipitation of acetylene.

The VC left is measured across a marked tube filled with phenolphthalein solution. The reading in the tube tells the % conversion of reactants.

8. SUGGESTION

N2 used in PVC is filtered out of atmospheric air in utility section and the remaining gases, which is rich in oxygen(more than 95%) is disposed off to the atmosphere. We can refilter this gas to obtain pure oxygen and can even install oxygen filling station.

9. PROJECT PROBLEM

Q. Calculate the flow rate of water in the given process. The process is post stripping process in which HCl vapours coming from the stripper are passed through 2 water coolers and 20% HCl is also cooled before sending it to the storage tank.

SOLUTION:

HCl vapours at 92-95 C

38⁰C

45⁰C

20% HCl (liq.) 75⁰C 18 m3/hr 45⁰C

CW 32⁰C

HCl Vapour

T⁰C

3

1 2

GIVEN:-

Density of 20% HCl solution = 1079 kg/m3

Specific heat capacity of 20% HCl solution = 2.99 KJ/kg.K

Specific heat capacity HCl vapour = 0.8 KJ/kg.K

Specific heat capacity of water = 4.18 KJ/kg.k

TO CALCULATE:

m = mass flow rate of CW

T=temperature of water exiting from 3.

By applying energy balance on 1 and 2

0.8 x 2500 x (92.5-45) = m x 4.18 x (T-38)

By applying energy balance on 3

2.99 x 18 x 1079 x (75-45) = m x 4.18 x (32-T)

By solving above two equations, we get

m = 73508.224 kg/hr

T = 37.698⁰C

m