POLY OLEFINSFeedstock : Naphtha / LNG / C2- C3 to light olefins to polymers 1 WHY POLYMERS ? Polymers ensued a new era to the society. Polymers are the materials of choice due to their versatility viz: Physical and Chemical strengths, Lightness in weight, Chemical and Corrosion resistance, Attractiveness, Easy processability, Durability in all whether conditions and finally Economic viability. . 2 Global Polymer Demand (2005-2020) . 2005 2013 2020 Polymer 170 220 270 PE PP PVC PS 60 50 30 10 80 70 30 20 90 80 40 30 MMT 3 Categarization of polymers Plastics: Formed by application of pressure and heat. Possess plasticity, rigidity, high mechanical strength, abrasive resistance, dimensional stability ,extensibility. Elastomers: High polymers with elastic properties, low modulus and molecular cohesion Fibres : Knitted or woven into dimensionally stable garments with high modulus and extensibility Coatings : polymers having low modulus and adhesion properties. high chemical inertness and impermeability towards water, solution and gases. 4 Plastics: PE, PVC, PS, PP, Polycarbonate, methyl methacrylate, Urea and Melamine formaldehyde, Polyurethene, Fluorocarbon. Poly Elastomers: SBR, PBR, Neoprene. Fibers: Nylons, Polyesters, Acrylic, Methacrylic poly olefins, Fluorocarbons, PP, Vinyls. Coatings: Epoxies, Silicones, Polyamide 5 Classification of polymer Stereo polymers are further sub-devided into Atactic, Isotactic and Syndiotactic polymers 6 Olefins Olefins serve as basic feed stock for many chemicals, intermediates etc. which are used in production of polymers, fibers, rubbers, pharmaceuticals, dyes, pesticides etc. Ethylene and Propylene are the most important light olefins. These are the building blocks for the chemical industry. 7 Naphtha Cracker Naphtha cracker remains the fundamental unit of the global petrochemical industry producing olefins namely ethylene, propylene, butadiene and pyrolysis gasoline. Various technologies for steam cracking across the world. 1 M W Kellog 2 Stone& Webster 3 ABB Lummus 4 Technil KTJ 5 Linde AG 8 Naphtha Cracker Unit Process technology : Cracker comprises of pyrolysis section, hot fractionation, compression, refrigeration, drying, cold separation and storage. 9 Details Pyrolysis heater : consists of convection zone and radiation zones where naphtha is pyrolytically cracked at 820⁰c to give a mixture of olefins.. Hot fractionation : Quenching and heavies separation. Compression section: cracked gases at 30⁰c are compressed in a 5 stage centrifugal compressor to a pressure of 40 kg/cm²g. Drying : the gas is then made free of moisture by means of molecular sieve 10 Cold separation: The gases are liquefied to sub zero temperatures -165 ⁰c by means of propylene and ethylene refrigeration systems. The cold liquid then is separated in various fractionation columns viz de-methanizer, deethanizer, ethylene fractionator, depropanizer, propylene fractionator and debutanizer. Storage : ethylene propylene and other separated liquids are stored either in refrigerated atmospheric tanks or Horton spheres under pressure 11 12 Offsite & storage Storage : ethylene, propylene and other products are stored either in refrigerated atmospheric tanks are in Horton spheres under pressure 13 Purity of c₂, c₃ & c₄ for polymers production Propylene: propylene 99.5 mole% propane 0.4 mole% MAPD 5 ppm Ethylene: ethylene 99.95 mole% ethane 300 ppm Butadiene: butadiene 1:3 99.6 % butadiene 1:2 20 ppm 14 PROPERTIES Mol. Wt. Melting Temp. MFI Particle size distribution Glass transition temp Amorphous density Crystalline density Softening point Izod impact Tensile strength 15 Polyethylene Discovered in 1935 by Mr.Gibson Demand of LLDPE: higher than LDPE & HDPE LLD : largest grade of commodity polymer in India LD+HD+LLD prodn in India in MTA RIL(IPCL) 4,20,000 RIL Hazira 4,00,000 Haldia petrochemicals; 3,20,000 IOC panipat : 3,00,000 16 Catalyst LDPE is prepared at high pres and high temp where as LLD. & HD at low pres and low temps. LD: peroxides HD: Ziegler Natta organometallic catalyst (a complex between al alkyl and transition metal halide such as titanium tetrachloride) LD: Copolymer of ethylene with olefins(c₄-c₁₀) 17 Production of LLDPE There are three major types of LOW PRESSURE processes for producing LLDPE / HDPE Slurry, Solution and Gas phase 1.Slurry process: using an inert diluents in which catalyst is affixed to an inert support. The polymer formed during production remains suspended in the liquid medium which is later separated. 2. Solution process: both catalyst & polymer remain dissolved in a solvent which is subsequently separated and recovered 3.Gas phase : monomer, co-monomer, H2, catalyst in pre-polymer form and inert gas N2 introduced in a fluidized bed type reactor. Gas phase processes have the widest application in terms of melt flow index and densities. 18 Limitations of various processes Slurry: Limited to densities > 0.937gm/ cm3and MI up to 10. Bimodal slurry processes have grown due to great demand for pipe and film production. Solution: Wider window in terms of densities and MI Best suited for higher value added products with Octane-1 Gas phase: Widest operating window for densities and MI. But encounters difficulties in resins with very low densities due to stickiness and agglomerate formation 19 Slurry type (a) Chevron Phillips 15% hexene, ethylene and supported catalyst are introduced in the reactor & isobutene as diluent. press 37 kg/cm²g, temp 100 ⁰ c (b) Solvay loop reactor 2% press 30 kg/cm²g, temp 80⁰ c 20 Phillips slurry loop process 21 Solution type : (a) SABIC-Compact hexane as diluent, Ziegler catalyst, ethylene, H2, butene-1 as co-monomer, press 2- 5 kg/cm²g, temp 150-200⁰ c MI range 0.1 -100,density 0.9- 0.967, (b) BASELL Hostalene 3% hexane as diluent, H2, monomer, comonomer and catalyst press 7-10 kg/cm²g , temp 75-85⁰ c (c) Dow 7% ethylene, octane-1, catalyst press 27 kg/cm²g temp 160⁰ c (d) Mitsui 9% uses hexane as diluent, comonomer butane-1 press 7-8 kg/cm²g, temp 85⁰ c (e) Dupont (now with Scaliartech) [NOVA] 5% cyclohexane. reaction time 2 mts 22 23 24 Gas phase process 1. Union Carbide UNIPOL 29 % 2. BP Amaco (Innovene) 10 % 3. Basell (Technimont) spherilene 2% Low capital & operating costs. Grade change over with minimum off grade production. Wide range of MI . Significant reduction in reactor purges. Easy reactor operation, grade changes on mathematical model and Interchangeability of production lines of LLDPE/ HDPE Low inventory in the process. Low pressure & low temperature process than conventional high pressure . 25 Gas phase fluidized bed reactor The reactor is a vertical type one. operating pressure 20 kg/cm²g and 70⁰c. N₂, ethylene, butene and H₂ are circulated in loop using a cycle gas compressor. Catalyst is made in-situ and grown to a bigger particle size by ethylene in a pre-poly reactor separately to reduce the activity of Ti, improve particle-size distribution and introduced into the reactor. Polymer powder is continuously withdrawn from the reactor and separated in a degasser. The gas is recycled back to reactor and polymer extruded out in pellet form for storage into silos 26 LLDPE Reactor Fluidised bed 27 Development in catalyst for ldpe/hdpe/lldpe 1.oxygen & peroxide 2 chromium 3. ziegler 4.supported catalyst for gas phase 5.metallocene 6.transition metal single site 28 Extrusion/ blending& transportation - powder silos - extrusion - sieving - transportation - storage and blending - off grade silos & recycling - packing 29 colouring & compounding - master batch preparation - extrusion to colour pelleting - packaging 30 Safety criteria in design -site & layout :- fire protection: -OSBL , -ISBL, -building & structures -process equipment and piping flare system drainage emergency shut down systems misc: safety showers, hot surfaces, noise levels ,escape provision 31 -Polymerisation: fire hydrant, sprinkler, flare, s/v, rov, co system, TEAL area, Plant emergency shut down system: cw ,power I.air, steam failure, external fire, -sensors and alarms. Pelletising section: dust explosion relief, -Bagging area: fork lifts, trucks movement -Monomer storage area: drainage, dykes, ROV, -Chemical storage and handling area 32 LLDPE / HDPE share by capacity & process 33 Capabilities of different processes per Density & Melt Index 34 Additives used in polymers Broad classification: (1) processing: stabilizers, slip agents, lubricants, accelerators, nucleating agents, impact modifiers, heat stabilizers. (2) functional: fillers, colorants, flame retardants, antistatic agents, antioxidants, antimicrobials. Market is dominated by plasticizers and flame retardants 35 Additive- commercial name Manufacturing stage (u/s & d/s of extrusion) 1. Anti oxidants- Irgonox 2. Lubricants: - Calcium stearate, zinc stearate 3.UV stabilizers 4. Antiblock agents: (silicons) - Gasil 5. Slip agents: (olemides) - Erucylamide 6. To prevent discoloration( thioesters) - DSTDP 36 Polymer properties / Applications Injection moulding: Mw/Mn <5 Toughness : lower MI Stress cracking resistance: lower density Easy processability : higher MFI Roto moulding: narrow mol.wt distibution High impact strength -doLow warpage -doLow shrinkage -do- 37 Plastics & uses PE LDPE Free radical initiate HDPE Ziegler natta LLDPE Ziegler natta HMWHDPE PP Homo Random PVC film sheet, house ware, pipe, toys, containers Ziegler natta Ziegler natta Fibre products, automobile parts, tyres, appliance parts, Ziegler natta toys house ware Free radical initiation wires cables, insulation, ,sheets adhesives, automobile parts, coatings, pipe fittings Free radical emulsion, paints, adhesives PVA PS film sheet, house ware, pipe, toys GP HI Expanded Free radical packing, disposable containers, appliance parts packing 38 plastics & uses- contd Poly isobutylene cationic chain lubricating oils, poly acrylonitrile (AF) free radical fibres in apperal, house ware Polyamide (Nylon 6) bulk Poly urethene poly conden oriented fibre, heavy cast parts, fabrics ,fishing line, furniture rubber, foam, coatings ABS free radical Styrene acrylonitrile (SAN ) free radical automobile aplliances, camera bodies, telephone parts electric equipment, house ware PMM free radical fixtures, aircraft windshield, cock pit cover , lenses poly carbonate poly conden trans esterifi step conden aircraft parts, CD, helmets, beverage dispencers dinnerware, table top poly conden particle wood binder, paper, textile Melamine formaldehyde urea formaldehyde 39 Many other polymers viz. epoxy resins, PBR, SBR, PET, polyester, PTFE, acrylic fibres, fluoro plastics etc. are yet to be covered There is no failure except in no longer trying Thank you 40