Vinyl chloride andpolyvinyl chloride

Thys

senK

rupp

A companyof ThyssenKrupp

TechnologiesUhde

Table of contents2

1. Company profile 3

2. The Vinnolit VCM process 4

2.1 General process description 5

2.2 Direct chlorination 6

2.3 Oxychlorination 8

2.4 EDC distillation 10

2.5 EDC cracking 11

2.6 VCM distillation 12

2.7 Measures to recover by-products and 13to protect the environment

2.7.1 HCl recycling with waste gas heat recovery 132.7.2 Waste water treatment 132.7.3 Liquid and waste gas collection systems 13

2.8 Cumulated capacity of reference plants 14

3. The Vinnolit S-PVC process 16

3.1 Description of the S-PVC process 17

3.2 Advantages of the S-PVC process 18

3.3 The new Vinnolit High-Performance Reactorfor suspension PVC 19

3.4 The Vinnolit MST Cyclone Drier 20

3.5 Products and applications 21

4. References 22

Page

Polyvinyl chloride (PVC)PVC is one of the world’s most versatile

thermoplastics with a wider range of uses than anyother plastic material. Its widespread use and

acceptance is not surprising, because PVC is versatile,durable, hygienic, safe and cost-effective. As such, it

has significant advantages over other materials.

With its highly specialised workforce of more than 4,900 employees and its international network of subsidiaries and branch offices, Uhde, a Dortmund-basedengineering contractor, has, to date, successfully completed over 2,000 projectsthroughout the world.

Uhde’s international reputation has been built on the successful application of its motto Engineering with ideas to yield cost-effective high-tech solutions for itscustomers. The ever-increasing demands placed upon process and application technology in the fields of chemical processing, energy and environmental protectionare met through a combination of specialist know-how, comprehensive service packages, topquality engineering and impeccable punctuality.

Uhde and Vinnolit – your partners for vinyl chloride and polyvinyl chloride

Our licensor for the Ethylene Dichloride (EDC), Vinyl Chloride Monomer (VCM) and for the Polyvinyl Chloride (PVC) process is Vinnolit GmbH & Co. KG.

Vinnolit is one of Europe’s leading EDC, VCM and PVC producers with a capacity of 780,000 t/year of PVC, 665,000 t/year of VCM and upstream chlorine plants. They enhance and optimise their process technology on a permanent basis.

Vinnolit was founded in 1993 as a 50/50 joint venture between Hoechst AG andWacker Chemie GmbH. The new company drew on the experience of its two founders,both active in the vinyl sector for almost 60 years. In 2000 Advent International acquiredVinnolit. Advent is one of the world’s largest and most experienced private equityinvestment firms.

Since 1964 the licensor has granted licences for a capacity of more than 10 milliontonnes of EDC, approx. 5.5 million tonnes of VCM and about 2.8 million tonnes of S-PVC.

The cooperation between the licensor and Uhde has been successful for some 40 years. Uhde is the sole basic engineering partner for Vinnolit’s EDC, VCM and PVC process.

31. Company profile

Uhde’s head office in Dortmund, Germany

Vinyl chloride (VCM), which is made from ethylene and chlorine, is used as feedstock in theproduction of the standard plastic material PVC.

The market for PVC and hence VCM has continued to grow, thus dispelling the forecastsmade in the 80s, according to which PVC wouldbe substituted by other plastics.

The reasons for this were not only the manifoldapplications and properties of PVC, but also theprogress made in limiting emissions and by-products during production. PVC productionattained growth rates of 4 - 5% per year,accounting for approx. 41 million tonnes world-wide in 2007. For the next few years, growth ratesin the order of 4% per year are again expected.

As a chemical engineering contractor, Uhdeadded VCM to its range of processes some 40 years ago and has to date designed andconstructed plants with a total nominal capacityof approx. 5.5 million tonnes.

The VCM process applied by Uhde is licensedby Vinnolit. The current high technological stan-dard was reached through intensive develop-ment work on the part of Vinnolit in collabora-tion with Uhde. The process has been success-

fully applied at Vinnolit’s existing plants atGendorf (Bavaria) and at Knapsack (Cologne),which have a combined capacity of 665,000t/year, as well as at many other plants worldwi-de.

The modern Vinnolit process for the productionof VCM has the following major distinctive features:

High operational reliability:

• Reliable reaction control

• Time-proven materials and equipment

• State-of-the-art process control system

High economic efficiency:

• High yields

• Optimised reaction conditions and reaction control

• Low energy consumption due to the utilisation of reaction and waste gas heat

• Utilisation of by-products containing Cl2 along with the recycling of HCl gas

• High on-stream factor

• Low personnel requirement

• Low maintenance costs

Extremely low pollution levels:

• 01 ppm VCM (annual average) in working areas

• Extremely low VCM emissions

• Small waste water quantities with EDC/VCM contents 1 ppm

• In-plant disposal of low-boiling and high-boiling constituents in conjunction with HCl gas recycling and steam generation

• Special facilities for preventing emissions when the plant is shut down

• Thermal waste gas treatment

Expected consumption figures for raw materials and utilities per 1,000 kg VCM product

Ethylene (100 %) 460 kg

Chlorine (100 %) 585 kg

Oxygen (100 %) 139 kg

Steam 125 kg

Electricity 120 kWh

Cooling water 150 m3

Fuel gas 2,720,000 kJ

2. The Vinnolit VCM process4

Qatar Vinyl Company (QVC),Mesaieed, Qatar

Capacities of the complex:360,000 t/year of EDC 175,000 t/year of EDC230,000 t/year of VCM

2.1 General process description

The process for the production of vinyl chloridemonomer (VCM) from ethylene proceeds in severalprocess sections.

In the first process section, ethylene dichloride(EDC; 1,2 dichloroethane) is produced by directchlorination, in the second section by oxychlori-nation. Both reactions are exothermal.

The EDC produced by direct chlorination is fed straight into the cracking section without any further purification.

The EDC formed by oxychlorination passesthrough a purification stage (EDC distillation).

In the third process section, the EDC is cracked,and the VCM formed there, as well as thehydrogen chloride and unconverted EDC, areseparated in a VCM distillation unit. The VCM istemporarily stored in a tank, while the HCl isreturned to the oxychlorination unit and theunconverted EDC to the cracking section.

Any process water obtained undergoes treat-ment. Waste gases containing pollutants as wellas liquid by–products are fed to the HCl recoveryunit and converted to HCl, CO2 and water.

The recovered HCl is reused in the oxychlorinationprocess, which leads to a complete conversion ofthe input chlorine.

The diagram shows the individual sections ofthe overall process which are described on thefollowing pages.

1st section:C2H4 + Cl2 C2H4Cl2 + 218 kJ/mole

2nd section:C2H4 + 2HCl + ½O2C2H4Cl2 + H2O + 238 kJ/mole

3rd section:C2H4Cl2 C2H3Cl + HCl - 71 kJ/mole

Schematic diagram of a VCM plant

ChlorineCl2

liquid + gaseousby-products

Directchlorination

EDCcracking

VCMdistillation

Vinyl chlorideVCMEDC

EthyleneC2H4

recycle EDCchlorination

EDCdistillation

OxychlorinationOxygen

O2HCl

by-productrecovery

HCl

VCM synthesis: 2 C2H4 + Cl2 + 1⁄2 O2 2 C2H3Cl + H2O

C2H4 + Cl2 Cat

C2H4Cl2 + 218 k J/mole

C2H4Cl2 ΔH

C2H3Cl + HCl – 71 k J/mole

C2H4 + 2 HCl + 1⁄2 O2 Cat C2H4Cl2 + H2O + 238 k J/mole

Biggest VCM plant in ChinaSINOPEC Qilu Petrochemical Corp.Linzi, Zibo, Shandong Prov., China400,000 t/year of VCM (balanced)

5

2.2 Direct chlorination6

In the direct chlorination process, EDC is pro-duced by means of a highly exothermal reactionof ethylene and chlorine.

The main feature of the Vinnolit Direct Chlorinationprocess is an innovative boiling reactor with nat-ural convection flow in an external reactor loop.

The Vinnolit Direct Chlorination process operatesat boiling conditions with a temperature of 120°C.The heat of reaction is removed by boiling off EDCfrom the boiling reactor. A big portion of this heatis then recovered by condensing the EDC vapoursin appropriate consumers, e.g. the EDC columnreboiler. This cuts energy use within the VCMplant by 300kWh per tonne of EDC produced.

The reaction is carried out in the riser part of the U-shaped loop. In contrast to other processes,gaseous ethylene is first completely pre-dissolvedin the lower part of the riser section.

Gaseous chlorine is added via an injector nozzle to a relatively small circulating EDC side streamwithdrawn in the downcomer section of therecycle loop and cooled to allow the chlorine tobe better pre-dissolved. This cooling providesanother opportunity to recover the heat of reac-tion, thus cutting energy consumption by up to100kWh per tonne of EDC.

The ethylene solution and the completely pre-dissolved chlorine are mixed in the reaction zoneof the riser and react to EDC in a fast liquid-phasereaction which significantly lowers by-productformation.

Due to the reduced static pressure head in thetop section of the riser, the EDC starts boiling.The product amount and some excess EDC arewithdrawn from the evaporation drum and passedon to the product vessel and a flash drum toachieve 'Sales EDC' quality, if required. Theexcess EDC is recycled to the main reactor loop.

In contrast to competitive direct chlorination pro-cesses, the Vinnolit Direct Chlorination processdoes not use FeCl3, but a complex inorganiccompound as catalyst. The catalyst suppressesthe formation of by-products and ensures higherselectivity to EDC.

Thus the Vinnolit Direct Chlorination processcombines the energy efficiency of a high-tem-perature chlorination (HTC) process with the EDCpurity of a low-temperature chlorination (LTC)process. The catalyst is fed to the reactor loopbefore start-up and does not have to be toppedup in normal operation.

The process is particularly environment-friendly, because:

• The formation of high-boiling constituents is significantly reduced

• Extremely small quantities of low-boiling constituents are formed (only a few ppm)

• No scrubbing water is required and

• No catalyst is discharged with the product.

The catalyst has no corrosive properties becauseof its complex structure, and therefore the pro-cess equipment can be made mainly of ordinarycarbon steel. Existing plants can be convertedwithout any difficulty.

The advantages of the process can be summarised as follows:

• Nearly no consumption of catalyst

• High EDC yield

• High raw EDC purity: 99.9%

• Utilisation of reaction heat, e.g. for heatingdistillation columns, thereby reducing thesteam consumption by 0.6t steam/t EDC

• Low investment costs

Utilising the reaction heat saves energy andreduces emissions of CO2 by an amount equiva-lent to the energy savings. Thus, carbon certifi-cate trading has a positive effect on productioncosts.

Refrigerant

CW

Ethylene

Chlorine

Boiling reactor

Reactorloop

Productvessel

Flash drum

Heatrecovery

Sales - EDC

Waste gas

to incineration

N2Heatrecovery

Furnace feed EDC

7

Direct chlorination unit LVM

Direct chlorination process using a boiling reactor

2.3 Oxychlorination8

In the oxychlorination process, EDC is formed bya highly exothermal catalytic reaction of ethylenewith hydrogen chloride and oxygen.

The reaction takes place in a fluidised-bed reactor, and the reaction heat is used for steamgeneration. In the downstream quench column,a major portion of the reaction water is removedby condensation. To remove small quantities ofchlorinated hydrocarbons from the reaction water,it is transferred to the effluent treatment facilities.

By cooling the reaction gases further by meansof cooling water (CW) and refrigerant (R), the rawEDC is removed by condensation and fed to theEDC distillation unit, where it is purified toobtain “feed EDC quality”.

The Vinnolit oxychlorination process can useoxygen from air separation units as well as oxygenfrom pressure swing adsorption units (PSA oxy-gen). In the reactor the catalyst is fluidised withcirculation gas. Just enough oxygen is added to the reactor to keep the concentration of thecirculation gas outside the flammable range(oxygen lean operation). The very small off-gasstream of inerts and carbon oxides which is formed in the process is fed to the HCl recycleunit without further treatment. The reaction mixture, consisting of C2H4, HCl and O2, is catalytically converted in the fluidised-bed reactor to EDC in a highly exothermal reaction at a temperature of > 200°C. The heat is dissi-pated via internal cooling coils and recovered togenerate steam. Independent of load the generated steam has a constant pressure level.

The excellent distribution in the fluidised-bedmakes it possible to maintain a constant tem-perature, to ensure low by-product formationand to achieve optimum process control. The reaction gas passes a filter unit in which the catalyst fines are separated from the gas. To remove the reaction water, the hot reaction

CW

Quenchcolumn Crude EDC

Waste gas to

incineration

Effluent to waste

water treatment

Circulating-gascompressor

Refrigerant

Hydrogen chloride

Oxygen

Ethylene

Hydrogen

Hydrogenationreactor

Oxychlorinationreactor

Boilerfeedwater

Steam

HCl from TDI / MDI possible

Catalystfiltration

9

gases are quenched and the EDC is condensedwith the aid of chilled water in a multi-stage condensation unit. The crude EDC is purified inan EDC distillation unit to obtain “feed EDC quality”.

The reaction water obtained is passed to thewaste water treatment facilities to remove thesmall quantities of chlorinated hydrocarbons it contains.

The modern oxychlorination process of Vinnolithas the following distinctive features:

• Fluidised-bed reactor with good reaction heat distribution: no hot spots

• Simple equipment

• Reactor and cooling coils made of carbon steel

• Crude EDC purity: 99.6%

• EDC purity after light-ends distillation: 99.8%

• High conversion of C2H4 to EDC: 99.0%

• Off-gas quantity: 1% of off-gas product viaair route

• Low catalyst consumption

• Removal of catalyst fines either by simplewaste water treatment or by catalyst filtration

• High flexibility of the plant

• Production of 10 bar steam for distillationunits possible

• High safety standard, O2 content < 1%

Oxychlorination reactor Erection of oxychlorination reactor BorsodChem Rt., Hungary

2.4 EDC distillation10

Waste gas to incineration

CW CW CWR R R

Crude EDC

fromoxychlorination

Recycle EDC

from VCM distillation

Headscolumn

High-boilcolumn

Vacuumcolumn

from cracking

High-boilingcomponents toincineration

Cracking EDC

Low-boiling components to incineration

Effluent to waste water treatment

EDC from direct chlorination

Steam

Cond.

EDC to direct chlorination

To produce pure feed EDC, both the EDC obtainedin the oxychlorination process and the EDC notconverted in the cracking process (recycle EDC)are treated in the EDC distillation unit in order toremove water as well as low-boiling and high-boiling constituents.

The wet raw EDC from the oxychlorination unit isfed to the heads column in order to remove thewater and low-boiling substances by distillation.The water phase of the head product containingsmall quantities of chlorinated hydrocarbonsand sodium chloride is transferred to the wastewater treatment unit. The organic phase and theoff-gas are fed to the incineration unit.

The dry bottom product from the heads columntogether with the unconverted EDC from thecracking process are separated from the high-boiling compounds in the high-boil and vacuumcolumns. These high-boiling compounds arewithdrawn from the bottom of the vacuumcolumn and sent to the incineration unit.

EDC evaporator and cracking furnace

2.5 EDC cracking 11

Cracking product

to VCM distillation

to VCM distillation

Recyle EDC

to EDC distillation

Cracking EDC

Fuel Fuel

SteamCond.

BFW

Steam

CW HCl

Cracking furnace EDC evaporator Quench

The cracking of 1,2 dichloroethane takes placein a cracking furnace heated by fuel. VCM andHCl are formed at temperatures of 480°C, thereaction being endothermic and incomplete. Inaddition to VCM and HCl, by-products of variouschemical structures and coke are formed.

The external EDC pre-evaporation facility reducesthe formation of coke in the cracking furnace con-siderably. The operating periods between twodecoking intervals are very long (up to 2 years).

The advantages of Vinnolit’s modern EDC cracking process can be summarised as fol-lows:

• High reliability due to low coking

• High cracking rate of up to 60%

• High savings in primary and secondary energy, due to:- External EDC pre-evaporation using

cracking gas heat- Utilisation of flue gas and cracking gas

heat to generate steam or to preheat combustion air

• Low maintenance costs

3D model of one of the world's largest PVC complexesARVAND Petrochemical Co., Bandar Imam, IranOn the left: The EDC cracking furnaces

Capacities of the complex:570,000 t/year of chlorine329,000 t/year of sales EDC343,000 t/year of VCM340,000 t/year of PVC

HCl column

Cracking

unit product

VCM column HCl stripper

Product

VCM

Recycle EDC

to EDC distillation

EDC chlorination unit

Heatrecovery

Steam

Cond.

Steam

Cond.

Steam

Cond.

CW

H2O removalHCl to oxychlorination

Cl2

from Cracking

quench

Refrigerant

CW

2.6 VCM distillation12

The product from the cracking unit consists ofVCM, HCl, unconverted EDC and by-products ofvarious chemical structures.

Hydrogen chloride is recovered in the HCl columnand fed to the oxychlorination unit. Vinyl chlorideis obtained at the top of the VCM column.

Any traces of HCl are removed from the VCM inthe HCl stripper. The overhead product of theHCl stripper is recycled to the HCl column via aH2O removal unit which removes moisture fromthe distillation process and protects against moisture build-up.

The bottom product of the VCM column, i.e. un-converted EDC, is returned to the EDC distillationprocess after the low-boiling compounds havebeen converted by chlorination to high-boilingcompounds. Thus the difficult separation of recycleEDC from other low-boiling compounds is avoided.

The Vinnolit EDC distillation unit can do withouta low-boil column for recycle EDC with all itsrelated problems.

Advantages of the VCM column:

• HCl content in VCM < 1 ppm without usingcaustic

• Long on-stream time of VCM distillation unit

• Vapour feed of HCl stripper overhead productto the HCl column, no condensation system necessary

Advantages of the recycle EDC chlorination:

• No separation of low-boiling compoundsnecessary

• Low investment cost in comparison to a low-boil column

• Easy operation

• No steam consumption

• Low maintenance cost

2.7 Measures to recover by-products and to protect the environment

13

The heat of the hot combustion gases is exploitedto generate medium-pressure steam, and thehydrogen chloride is recovered as a valuablefeedstock which is returned in gaseous form tothe oxychlorination process.

Alternatively, aqueous HCl of 25 to 30% can beproduced.

The treated waste gas complies with all applicable German statutory regulations in forcesince 3.5.2000, including those concerning the concentration of dioxins and furanes (< 0.1 ng TE/m3).

The advantages of the HCl recycling processare:

• Recovery of hydrogen chloride from the by-products

• Optimum utilisation of the input chlorine toproduce VCM

• Utilisation of the energy content of the by-products in the form of medium-pressure steam

• Use of proven technology and materials

• Environment-friendly process

2.7.2 Waste water treatment

The process effluent from the VCM plant and anysplash water are sent to a waste water treatmentunit. Chlorinated hydrocarbons are removed bydistillation, hydrogen chloride by neutralisationwith caustic soda solution. A copper content ofless than 1 ppm is ensured either by dry catalystfiltration in the oxychlorination or by treatment ofthe waste water using flocculation, sedimenta-tion and filtration.

The treated effluent, which meets the statutorypurity requirements, is subsequently fed to abiological treatment unit.

The sludge obtained as a waste product is dumped.

2.7.3 Liquid and waste gas collection systems

Liquid EDC and VCM from drains, cleaning of filters, reboilers etc. are collected in closedsystems and returned to the process loop toprotect the environment.

Sources of continuous waste gas streams areconnected to waste gas headers and the gas issent to the HCl recovery unit.

2.7.1 HCl recycling with waste gas heat recovery

In the production of VCM, not only 1,2 dichloro-ethane is produced as a desirable intermediateproduct, but also further by-products, consistingof a mixture of high-boiling and low-boilingcompounds, are obtained in liquid or gaseousform.

In a new modified Vinnolit process, these by-products are completely converted in an oxidationprocess to form CO2, water and hydrogen chloride.This process operates with an excess of air atapprox. 1,150°C.

HCl recovery unit

2.8 Cumulated capacity of reference plants14

1970

1

2

3

4

5

6

7

8

9

10

EDC

VCM

1980 1990 2000 2010Year of commissioning

mill

ion

tonn

es p

er a

nnum

Cumulated Capacity of EDC & VCM Plants Designed by Uhde

Uhde is one of the world’s leading engineering companies in the fields of EDC and VCM, having built plants with a total capacity of more than 8 milliontonnes per year of EDC and approx. 5 million tonnes per year of VCM (see diagram).

15

The view of Europe's biggest and most modern VCM plant at Vinnolit in Knapsack near Cologne.

Capacity: 190,000 t/year of EDC370,000 t/year of VCM

3. The Vinnolit S-PVC process16

The suspension polymerisation process formanufacturing polyvinyl chloride is the mostimportant way to produce a variety of general-purpose and highly sophisticated grades ofPVC. This process was invented in 1935 andfirst patented by Wacker Chemie GmbH, one of the former parent companies of Vinnolit.Continuous developments had been made inrecipes, product quality and technology. Due tothis long experience and continuous improve-ments, Vinnolit can offer a modern and highlyeconomic process for the production of S-PVCworldwide. A Vinnolit team of specialists is avail-able to tailor plant design according to licensee’srequirements.

Vinnolit technology is characterised by:

• Vinnolit‘s proprietary technology for all units

• Clean and closed reactor technology

• High productivity of up to 600 t/m3/year

• Low raw materials consumption

• Low energy consumption

• Low investment cost

• Low maintenance cost

• High safety level

• Leading in environmental protection – DIN ISO 14001 certified

• High product quality – DIN ISO 9001 certified

3D model of one of the world's largest PVC complexes ARVAND Petrochemical Co., Bandar Imam, Iran

Capacities of the complex:570,000 t/year of chlorine329,000 t/year of sales EDC343,000 t/year of VCM340,000 t/year of PVC

3.1 Description of the S-PVC process 17

Slurry

VCM

Activator

Demin. water

Dispersing agent

Recovered VCM

CW

CW Steam

Air

to waste water treatment unit

PVC powder to silo

Steam

Centrifuge

Cyclone dryingsystem

off-air

High-performance-reactor

Blowdownvessel

Pre-degassingvessel

Degassingcolumn

DryingPolymerisation Degassing

Vinyl chloride and hot water are fed to theVinnolit High-Performance Reactor by means ofa special charging program.

Once the polymerisation has been completedthe content of the reactor is discharged into ablowdown vessel and from here continuouslyfed to the Intensive Degassing System.

The nonconverted monomer is stripped out,condensed and fed back into the process.

After degassing and recovery of the latent heat,the water is separated by centrifuge and the wetPVC leaving the centrifuge is fed into the dryingsection.

The wet PVC is dried by means of heated air inthe Vinnolit MST Cyclone Drier.

After drying, the PVC powder is conveyed pneumatically to the silo and bagging unit.

Consumption figures for raw materials and energy

Low consumption of monomers, chemicals andauxiliary materials, low energy consumption dueto extensive heat recovery, and energy-savingdrying technology result in reasonable produc-tion costs.

Consumption per 1,000kg of PVC powder at the production plant including VCM recovery:

Vinyl chloride 1,001 kg

Demineralised water 2.3 m3

Chemicals 2.5 kg

Steam 0.8 t

Electrical energy 170 kWh

This data is based on average values. The consumption values depend on K values,on product type and location.

*)

*) waste water recovery not included

3.2 Advantages of the S-PVC process18

Clean reactor technology

Scale-free operation is achieved through the useof reliable lining inhibitors, optimum operatingconditions during polymerisation and a reactordesigned to suit the requirements specified.

This means:• High-Performance Reactor• Clean and closed reactor technology• Downtimes e.g. for the opening and cleaning

of the reactor are eliminated• Heat dissipation remains constant

It is therefore not necessary to frequently openthe reactor for cleaning purposes.

Process control system

The whole plant is controlled with the aid of a digital process control system.

This results in:• Precise metering of the individual compo-

nents during reactor charging• High constancy of the present process

parameters• Excellent reproducibility of the process giving

extremely consistent product quality• High level of plant safety and reliability• Low personnel requirement

Intensive Degassing System

Our own work on the development of an intensivecolumn degassing technology has resulted inperfect, continuously operating processes withthe following conditions:• Extremely low residual VCM content in the PVC• Gentle degassing conditions• Grade change without opening the column• Extremely low VCM emissions and low

VCM consumption of the S-PVC process

Drying

In the Vinnolit MST Cyclone Drier the drying process is adapted optimally to the dryingmechanisms taking place during the drying of the PVC.

This leads to gentle drying conditions, highlyeconomic operation and minimum maintenancerequirements.

The cyclone drying process is particularly characterised by the following:• Low investment costs• Low energy consumption• Gentle drying process due to low drying

temperature• Selective drying i.e. varied drying time

according to size of particle, thus avoidingoverdrying or thermal degradation

• No wall incrustation, therefore avoiding anyproduct contamination

• Short period of time required for grade change

The safety concept

The whole safety concept, including its computerprocess control system, permits a particularly highlevel of operational safety.

In addition, the polymerisation system is completely safeguarded and can stop the reactionunder extreme conditions e.g. simultaneous failureof coolant and power supply.

Emissions

According to Vinnolit’s commitment with regardto environmental protection, the offered S-PVCprocess sets a new standard.

Clean and closed reactor technology, processautomation and effective degassing of productmeans that VCM emissions are kept at an extremely low level and under normal operatingconditions are far lower than the figures requiredat present:• Less than 1 mg/m3 in drier off-air• Less than 1 mg/m3 in waste water• Less than 1 vol. ppm (shift average value

in the air at the workplace).

Effective measures keep PVC emissions in thedrier off-air to less than 10 mg/m3.

Polymerisation Reactors

PVC High-Performance Reactor (inside view)

3.3 The new Vinnolit High-Performance Reactor for suspension PVC

19

A B C D E

Suspension

Step by step Vinnolit has realised all requirementsfor a high-performance polymerisation reactor.The inner cooler reactor was developed as a lastlink in the optimisation. This completely newreactor design has been created and improvedby Vinnolit engineers. The inner cooler reactorhas demonstrated its outstanding suitability forthe production of suspension PVC on an industrialscale for many years and is therefore a provendesign.

In view of Vinnolit’s inner cooler reactor, thechoice was made for a combination of:• Increased heat transfer area due to the

half-pipe coil on the inner reactor wall and• Improved heat-transition coefficient due to

the reduced thickness of the half-pipe coil• Increased heat transfer due to higher

turbulences at the wall.

This design combines high heat transfer ratewith safe operation in a closed mode. Of coursethe other internal components of the inner coolerreactor like the agitator, baffles and nozzles areoptimised as well to apply the clean reactortechnology in the same way as in Vinnolit’s conventional reactors.

The essential advantages of the Vinnolit High-Performance Reactor are:• High output of up to 600 mt/m3/year

- Very short non-reaction time- Very short reaction time

• High quality of product grades- Use of the Vinnolit recipes- Wide range of licensed grades- Heat dissipation only in the liquid phase

as in a conventional reactor• Large reactor volumes of up to 175m3 ensuring

- Low investment costs- Low maintenance costs

• Large heat transfer area and high heat-transition coefficient, providing a coolingcapacity twice that of a conventional reactor;therefore no additional cooling area(such as a reflux condenser) is required

• Very simple and safe operation- Closed and clean reactor technology:

using the Vinnolit anti-fouling technology-dispenses with high-pressure cleaning or reactor opening

- Automatic catalyst charging- Simultaneous charging of hot water and VCM- No heating up by means of a heating jacket

• Low operating costs because of- Adapted recipes- Use of cooling water instead of chilled water

The requirements of a modern high-performancepolymerisation reactor with a high productivity:• Short non-reaction time to be reached by

- Closed and clean reactor technology- Efficient anti-fouling technology- No reactor opening - No high-pressure cleaning- No heating up of the batch- Optimised charging procedure,

i.e. simultaneous hot water/VCM charging- Automatic catalyst charging

• Minimal reaction time to be reached by- Fast reaction-heat dissipation- Large reactor technology - Volumes up to 150 m3

- Adapted recipes

To achieve a minimal reaction time, the reactionheat has to be dissipated out of the reactor quickly.• by increasing the heat transfer area by

arrangement of half pipe coils inside• by increasing the differential temperature

between inside reactor and jacket, e.g. usingchilled water

• by improving the heat-transition coefficient,e.g. using a thinner wall between inside reactor and cooling water

• by adding an external condenser

A Cooling channel

B Cladded steel wall

C PVC-suspension

D Half-pipe wall

E Cooling coil

Heat transfer graph (typical)of conventional reactor cooling

Heat transfer graph (typical) of Vinnolit’s High-Performance Reactor

3.4 The Vinnolit MST Cyclone Drier20

Description

The MST Cyclone Drier, a development ofVinnolit, is a convection-type drier with all thetypical advantages of such a system (gentledrying in co-current), but without the disadvan-tage of an extremely short residence time of theproduct in the drier. By subdividing the cycloneby means of horizontal annular baffle plates ofconical shape into a plurality of chambers intowhich gas and solid particles are fed via anhelix, residence times of up to 30 minutes areachieved. As a result of the rotational flow incombination with the annular baffle plates, thegas and the solids continually separate andredisperse at a high differential velocity and correspondingly intensive heat and massexchange. In this process, the residence time ofthe particles varies with their size: the larger thesize and the higher the moisture content, thelonger the residence time of the particles. Thisselective effect is the main characteristic featureof the MST Cyclone Drier and results in all particles leaving the cyclone with roughly the same moisture content, irrespective of their size.

Application

The MST Cyclone Drier can be used for dryingpourable and fluidisable particulate matter, thelargest particle size being limited to about 1 mm.It is especially suitable for drying hygroscopicmaterial (after predrying to below the criticalmoisture content). A particularly economicalsolution is the combination of a MST CycloneDrier with a flash drier or any other type of drierwith short residence times in which the surfacemoisture is removed while recycling the off-air.

Cyclone driers are in use for:S-PVC, polymethyl metacrylate, various plantprotection products, pulp, sesame seeds, andvarious inorganic chemicals.

Advantages of Vinnolit´s MST Cyclone Drier

• Gentle drying in co-current at a low tempera-ture level

• Intensive heat and mass exchange as a resultof high relative velocity of gas and solids

• Uniform final moisture of all particles, nodamage due to overheating or overdrying ofthe fines

• Easy to clean, no moving parts• Short shut-down periods and low material

losses during grade change• Low investment costs

top:View into the Vinnolit MST Cyclone Drier

below:MST Cyclone Drier, Georgia Gulf Corp.,Aberdeen, MS, USA

MST Cyclone Drier, Georgia Gulf Corp.,Plaquemine, LA, USA

3.5 Products and applications 21

Application K value Viscosity Bulk Screen analysis Plasticisernumber density absorption

Test method g/l < 63μm > 250μm > 315μm ISO 1628/2 ISO 1628/2 DIN 53468 DIN 53734 DIN 53417

Injection-moulded articles, 57 80 570 2 % < 1 % < 0.1 % lowrigid film, hollow articles

Rigid film, injection-moulded 60 89 560 2 % < 1 % < 0.1 % mediumarticles, plates, bristles

Rigid and semi-rigid 65 105 580 1 % < 5 % < 0.1 % mediumsections

Rigid pipes and sections 67 112 570 1 % < 5 % < 0.1 % medium

Rigid pipes and sections 68 116 570 1 % < 5 % < 0.1 % medium

Plasticised film, sections 65 124 490 5 % < 1 % highand flexible tubing

Plasticised film, sections, 70 124 470 5 % < 1 % highinjection-moulded articles,cable

Platicised film and profiles, 75 145 470 5 % < 1 % < 0.1 % highmedical articles

For further product information please refer to Vinnolit’s internet hompage: www.vinnolit.com

S-PVC, in particular, can be produced in both a crystal clear, hard and a very soft flexible finished form, with good electrical and dielectricproperties. Only the major applications of thedifferent basic types are listed as follows:

• Coarse-grained, porous, free-flowing S-typeswith a high bulk density for rigid and semi-rigid extrusion (pipes, sections, plates), bubble extrusion (hollow items) and injectionmoulding, low-fish-eye S-types for the calendering of rigid and semi-rigid film, theproduction of PVC bristles and deep-drawablerigid film.

Probably no other plastic can match the wide variety of possible uses offered by PVC.

• Coarse-grained, highly porous, free-flowingplasticiser S-types for dry blend production,free-flowing plasticised PVC mix for low-fish-eye extrudates and film, for cable sheathsand hoses.

• Fine-grained special types for special applications.

4. References22

Recent references of EDC and VCM plants

Completion Customer Plant Site Product, Plant Capacitymtpy

2010 S.N.E.P. Morocco EDC Direct chlorination, 115,000EDC, Oxychlorination 112,000

2010 Sayanskchimplast Russia VCM, EDC Cracking 200,000

2009 ARVAND Petrochemical Co. Bandar Imam, Iran EDC, Direct chlorination 551,000EDC, Oxychlorination 332,000(Sales EDC) 329,000VCM, EDC Cracking 343,000

2008 Formosa Plastics Corp. USA EDC Cracking 240,000

2007 Sahara Petrochemical Co. KSA EDC Direct chlorination 300,000(Basic engineering implementation pending)

2008 Tokuyama Corp. Japan EDC, Direct chlorination 200,000(Basic engineering for feasibility study)

2007 Liwa Petrochemical Sohar, Oman EDC, Direct chlorination 307,000Company LLC

2006 Limburgse Vinyl Tessenderlo, Belgium EDC, Direct chlorination 250,000Maatschappij (LVM)

2005 Sasol Polymers Sasolburg, South Africa EDC, Direct chlorination 168,000EDC, Oxychlorination 160,000VCM, EDC Cracking 205,000(Expansion)

2005 VESTOLIT GmbH Marl Germany VCM, EDC Cracking 190,000(Revamp)

2004 Sinopec International / Zibo, Shandong, China EDC, Direct chlorination 330,000Qilu Petrochemical Co. EDC, Oxychlorination 315,000

VCM, EDC Cracking 400,000

2004 BorsodChem Rt. Kazincbarcika, Hungary EDC, Oxychlorination 225,000(Expansion)

2004 Shanghai Chlor Shanghai, China VCM, EDC Cracking 130,000Alkali Chemical Co. (Expansion)

2003 Petkim Petrokimya Aliaga/Izmir, Turkey EDC, Direct chlorination 136,000Holding VCM, EDC Cracking 152,000

2002 Vinnolit GmbH & Co. KG Knapsack, Germany EDC, Oxychlorination 170,000VCM, EDC Cracking 330,000

2001 Qatar Vinyl Co. (QVC) Mesaieed, Qatar EDC, Direct chlorination 360,000EDC, Oxychlorination 175,000(Sales EDC) 175,000VCM, EDC Cracking 230,000

2000 Vinnolit GmbH & Co. KG Gendorf, Germany VCM, EDC Cracking 310,000(Expansion)

1999 Panjin VCM Co. Ltd. Huludao, China EDC, Direct chlorination 70,000

1999 Sinopec International Qilu, China EDC, Oxychlorination 80,000

1999 Petkim Petrokimya Aliaga/Izmir, Turkey EDC, Oxychlorination 125,000Holding

23

Recent references of PVC plants

Completion Customer Plant Site Product, Plant Capacitymtpy

2010 Lukoil Neftochim JSC Kalush, Ukraine S-PVC, Polymerisation 300,000S-PVC, DegasingS-PVC, Cyclone drier

2009 S.N.E.P. Morocco S-PVC, Cyclone drier 85,000

2009 Ercros Spain S-PVC, Polymerisation 120,000

2008 Spolana A.S. Czech Republic S-PVC, Cyclone drier 2 x 100,000

2007 Braskem Brasil S-PVC, Polymerisation 130,000

2007 Undisclosed USA S-PVC, Polymerisation 250,000

2006 ARVAND Petrochemical Co. Bandar Imam, Iran S-PVC 300,000PVC-E 40,000

2002 Zaklady Azotowe w Tarnow, Poland S-PVC 100,000Tarnowie-Moscicach

2001 Royal Polymer Ltd. Sarnia, Canada S-PVC, Cyclone drier 80,000

1997 S.N.E.P. Morocco S-PVC, Cyclone drier 52,000

1996 Hydro Polymers Ltd. Newton Aycliffe, UK S-PVC, Cyclone drier 92,000

1996 Georgia Gulf Corp. Aberdeen, MS, USA S-PVC, Cyclone drier 110,000(former Vista Chemical Corporation)

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