Polymerization Reactions PDF
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The document discusses various chemical reactions and concepts related to polymer chemistry, including redox reactions, initiation, propagation, and termination steps in polymerization. It also covers thermal degradation and chelating agents. It contains tables and diagrams related to the different processes explored.
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# Prawdown - 3,000 in reactor before yous hoot vazo - 13,000 Full Reaction - Vazo Shoold spin min of 30 min - PH-700 neutral - Evaporative - Di Forsional Pryers - COOL DOUN - VE-FAN 13x PPM - VI. Screw - 5- Dryer - Mi-Motor - Gr-Granulator - Ecy Cyz-Rotaryvalve - -3500 ML, 30 min - MBA-Brancring age...
# Prawdown - 3,000 in reactor before yous hoot vazo - 13,000 Full Reaction - Vazo Shoold spin min of 30 min - PH-700 neutral - Evaporative - Di Forsional Pryers - COOL DOUN - VE-FAN 13x PPM - VI. Screw - 5- Dryer - Mi-Motor - Gr-Granulator - Ecy Cyz-Rotaryvalve - -3500 ML, 30 min - MBA-Brancring agent - Hypo - UL molecular weight controlled by hypo viscosity ## Catalyst MIX TIMES - va20~75° or below - AZDN-5 min - Hypo- 5 min - JA-044-5 min - Thermal Cataylorst - TBHP- 30 seconds - Sodium Persulfate- 5 min - Mohr's Salt-min- reducer - VAZO-Thermata catalyst ## Redox Reactions - Oxidizers - Sodium Persulfate - Tert-Butyl Peroxide CTBHP) - Potassium Bromate - Reducers - Sodium Metabisulfate (MBS) - Sodium Sulfite - Monr's Salt - Sodium Formaldenyde sulforiate CNAFS) ## Redox Reactions - Thedox reactions are used to initiate the polymerization. - We then measure the induction period to ensure that the reaction has actually started. Induction time is the time between when the reducer is trons ferced Until the reaction temperature enonges 0.2℃ on the torpature parel in the field to a 0.3°C. - This is usually less than 60 seconds but can be up to a few minutes. - Induction time is shorter for lower molecular Weight and longer for higher molecular weight products. - Increasing the redox catalyst will result in a faster Kinetic. - Decreasing the redox Catalyst will result ina Slower Kinetic. - We use Monr's Salt as our main reducer to kick off a reaction. - Cyclone Purpose-re Captures good product goes trough transitoned back to dryers. - Acrylamide-inhibited by copper and oxygen. - Copper inhibits polymerization by reacting with any free radicals before the free radicals con react with monones Molestes. ## Thermal Degradation - Thermal catalyst must be stored in cold storage to keep then Chemically Stable and to extad the shelf life up to or past 3 months. - Thermal catalyst not kept in cold storage begin to degrade and form free radicals. - byproduct of the degradation of vazo 64 is TMSN (Ctetramethyl succinonitrile) and is highly toxic - Thermal degradation accelerates the reaction to completion without thermal catalyst to accelerate the reaction the UL viscosity would build very Slowly, and too Large. - So large as to degrade solubility. - Diffrent thermal catalyst degrade at diffront tempatures and react for a different amount of time. ## Steps of Polymerization - Initiation - Initiation occurs when the reducer from redox is added to monomer Solution. - Propagation-Chain will contince, Thermal catalyst/chin tromstor agent drive propagation Step. - Termination 3 Causes) - Absence of monomer - Disproportionation when another free radical attach the end of the polymer crain - Combination when 2 Chains with free radicals Combine. ## Auto Initiation - Can happen if hot gen is left over from the last reaction. - If the Soloution is not at the set point in the dissolution tank during the transfer to the reactor. - If there is left over catalyst in the reactor during the drawdown ## Sparging-Polymerization - Sporging is a very critical factor in making in-spec polymer - Sporging is the injection of nitrogen at the base of the reactors to displace oxygen in the reactor and dissolve in the polyacrylamide Solution - Oxygen is an oxider and will inhibit the redox reaction from occurring, Oxygen inhibits polymerization ## Sparging, Pressure and Flow-rate - Sporge pressure or flow-rate is too low not enough oxygen will be removed from the baten during set Sporge time and there will be inadequate mixing of catalyst. - Triscauses the reaction to be slow to start ressiting in on erratic reaction rate - If the sparge rate is to nign this can lead to poor Catalyst mixing and crractic curves resorting in off spec product. - High sparge rates can also cause foaming in the reactor whion can cause over monomer into the Venting System. - Leaks in the nitrogen line can result in air being Socued in to me nitrogen live causing inition and vinetic problems. - DCS is reading a low sparge rate the issue could be a Clog sporge cone are a closed Valve ## Chelating Agorts - when aq seous acrylamide is supplied from anywhere besides SNF Flopam it is inhibited with copper metar in Solution to prevent premonture initiation. - Then copper must be separeted from the acrylamide so that we can control the initiaton to when we want it to Start. - We using the che la fing agent versenex 80 to accomplish this. - - Vesenex 80 has the largest affinity for Copper. - - Also nas an affinity for I ron, whion we use to start a reaction. - To deep the Iron free and available for free rasion formation Must use the Corront amant of ver senex 80. ## Chelating Agents - Versenex 80 can also be used as a catalyst if a large amount is added to a reaction. - Excess Verzerex 80 will chelate all the copper and iron. - Chelated iron is muon more reactive than uncrelated icon and will accelerate the reaction, thus acting as a catalyst. ## Branening and crosslinking - Branening increases molecular weight without increasing the viscosity-MBA. - Certain applications can benefit from this Characteristic - Bramaned products Still have good solubilitty. - Cross linking is extreme broncring that decreases Solubility. - Cross linking is not desired and should try to be avoided. ## Product Solubility - Solobility is the measure of a polymers ability to dissolve in water. - Primary reason for poor solubility is excessive tempatures in the dryers and during polymerization in the reactors. ## Hydrolysis for Poor Solubility - In the i ther case the issue is caused by crosslinking the polymer. - Poor Solubility during polymerization can be due to. - UL too high. - Branching a gent concentration too high. - Residual acrylamide too high. - Hydrolysis occur more more in lower anionic product. - Cousing a blue/green tint. ## Hydrolysi s - Hydrolysis is a chemical reaction where the water with another substance to form two or more new substances. - In polyacrylamide production, nyorolysis occurs When the new tral amine group on the poly ner chain is converted to an anionic acrylic acid tail, giving the Chain a negative Charge. - The more hydrolysis that occurs, the higher the charge of the Polymer chain. - WE USE CAUSTIC FOR HYDROLYSIS IN OUR REACTIONS. - Tempature of the aqueous monomer during the addition of Caustic Shoots up so we must make sure to leave the heat exchanger running ant not allow the tempature to rise above 12°C. ## Kinetics - Time - is the rate of temperature us time. - is measured on a X-Y chort. - Temperature - Most reactions Start O°C, and heat up to 75-100°C. - Some products are initiated at nigner temperatures, but never above 20°C. - If the reaction does not reach a high enough temperature there will be lett over monomer in the form of a liquid. - Federal regulation will not allow us to sell polyacrylamide With a monomer content over 1000ppm. - A reaction that rises above look will cause the water in the reaction to Convert to steam and expand the gel in to the Vent line. This should be avoided as much as possible, If this occurs check dissolution tank Charge and catalyst Package. - Reactions can take from 30 minutes to over 3 hours to run. The amount of time it talles will depend on the Molecular weight of the product. - Meactions that run too quich will lively have a low UL viscosity Coff-Spec?, - Reactions that ron too long will lively not reaan haugh tempature and have a nigh monomer Contort. ## Free Monomer -'Free Monomer' are the unreacted or un-polymerized monomer molecules used to mave Polyacrylamide gel. - Free monomer is the measure of the amount of acrylamide that has not been converter in to polyacrylamide. - Free monomer normally happens when the plants have a leaking drain Vavive. ## Reactor - Reactors are vessels where we charge the liquid Monomes and Change this mix into polymer gel. - Polymerization is the process of mouring gel. - Polymerization begins when the Polymerizer rovoves the oxygen and adds the Catalyst. - We sell products based on the length of the resulting Polymer chains and the charge of the Chains. - Longer the polymer chains harder it is to dry the polymer without Cowsing Solubility problems ## How does The Reactor work 22 - The polymerizer fills the reactor with a mix of monomers: - acrylamide - acrylic acid - Water - additives - anps - PH adjusters - Cat Monomer - Finis mix is polymerized by sparging with nitrogen and by the addition of Catalyst. - Heat is released astre monomers react to form polymer enains. This heat makes the gel not. The mixture Starts at the freezing part of water, O°C and can peak out near the boiling point of water, 100°C. - The primary characteristics of the product we more are Chorge and molecular weight (chain length). These are created in polymerization, The charge is created by adding acrylic acid or cat monomer. The Molecular weight is increased by decreasing the amount of Catalyst and enain trastiver agent. - tube reactors are dumped by pressurizing the reactor and forcing the gel through a discnage pipe. ## Reactor Trouble Shooting - The reactors are lined with a Teflon live coating or they are electro polished. If the gel will not dump and tre lubrication is good the liners may need to be changed. - If the reactors peak at too hot of tempature the cause Could be too much monaner and not enough water. - Or the reaction could have been started at too high tempature. - If the baten peaks above the boiling point of water the gel can be forces violently out of the reactor. - Diffrent temps between reactor tomp probe could be because of a beat or bad probe. ## What to Do When BAD I Show Meaction Detected - Get DTank Sample to Poly tean for analysis ## Why do we need them? - Gel Hoppers ## Weigh Cells - The gez Hopper is used to maintain a Consistent flow of product to the granulator. - The product is growity - fed to the dosing screw and is that pusned into the granulator through the action of the screw. ## How does the Hopper work? - The gel nopper is set to maintain al consistent weight fof product on the dosing screw. - This set Point determines when more product should be added so that the feed is not interrupted. - When bel Hopper dips below the set point the automatic Bequences within the DCS will begin the process of filling the gel hopper back up. ## Safety Concerns - Follow confined space procedures if you enter the gel hopper. ## Trouble Shooting Issues - If the load cells on the gel hopper are malfunctioning, the DCS will not have a corect weight binitiat Seane. ## Pre-Grinder - The primary purpose of pre grinding is to tear the gelin to Smaller pieces so that the feed will be consistent. - If the feed to me granulator is not consistent the flow through the dryer will not be consistent. - This will cause non- uniform drying. The pregrinder is also used to post - treat gel, blend dust, and rework product. ## Pregrinder - VIA, VI2, VI3, VI4, VI5 - The pre-grinder tears the gel through the use of screws. - The weight of the gel forces it against the moving Sarow Screws. - The screw works best when the gel is hot, colder the gel the more difficult it is to pre grind. - Broducts live 934SH and 923 SH grind very easily. - Low UL products like VLM and BPM are more difficut to grind. - Very High Cationic product can be difficult to griod gring due to stickiness of a product. ## Pre Grinder - If a product that is normally easy to pre-grind will not grind there maybe a problen with the get. - If the gel is hard to grind, the Un may be to o hign. - If the gel lays flat the UL may be too low. - Gelenters the pre-grinder through the reactors, Once tre gel nas Rinisned reacting and peaved out, it is held in the reactor to help reduce the un-reacted acrylamide monomer. - The gel is dumped by hydraulic Cylinders for cubic reactors or by pressure in the tube reactors. - When tre gel is dumped the screw shoud be turning forward. This helps to poll the gel out and reduces the Strain on the gear motors. ## Pre Grinder (cont.) - A grinding aid, Lubchopnos PK 455 is added to many products to make the gel easier to cot. - ine first half of the surfa cont is added directly to the Screws be fore the gel is dumped. - Once the screws nowe bean Coated the gel can now be Dum ped. - After the gel is dumped it is run forward for 20 min. - After grinding for 20 min the gel is reversed, when the gel has been pulled back, the second half of the Surfactant is added. - Some products do not require Surfacants because they pre grind easily. - Adding too much Surfacant can cause the gel to become too fine and willping the granulator and ten. - Surfacont helps to mave the gel less Sticky because the hydrophilic end of the surfacant is oriented out. - The lipophilic end reeps tre gel from sticking to Surfaces and to itserf. ## Pre Grinder(Cont.) - The first half of the treatment is added whent the gel is Pulled back. - The post treatment is MBS for Cationics and sodium Sulfite for anionics. ## Pre Grinder(Cont.) - We also use Sodium Sulfate in blending, This will not work as a post treatment additive. - the post treatment reacts with the monomer rencing in the gel. For post treatment to be effective, it must be evenly spread over the gel and then well mixed in to the gel. - The second Half of the post treatment is added once the gel is returned forward. The gel is then allowed to pre grind for another 10-15 min. - The better the post-treatment is mixed in to the gel the more effective it will be at lowering the monomer. - The amount of post-treatment will be listed on the conditions Sheet and written on the pregrinder board in the control room. - Some products are not post-treated because it coves too great of a loss of OL. ## Pre Grinder (Cont.) - Monosodium Phosphate is also added to the pre-grinder. - ine monosodium phosphate helps to reduce corrosion which Con lead to specks in the gel. - The mono sodium phosphate is sometimes placed directly on the screws if there a lot of specks. - monosodium Phosphate is added at Oil % based on the weight of the gel, Cokgs of Mono Phosphate Would be needed for a 6000 kg baten. - Dryer operator Should check to make sure the gel is grinding and moving evenly, bel can tomel out on some products When it is run forward, for too long: bel con also get hung up and not move uniformly, some products require more attention than others. ## Span 80 Tuelen 80 - Vazo Pot - PK 455- Added in Diffront concentrations to Process. - 5275- - LP3- LPA OIC - PPEOIL - GRZ ## Salt concentraion - Becher - Soo ML-Zero OUT- Salt tave Solution - Weigh it : 500 Specific Gravity ## LPLH-Steam Jacket - 1. 7- Post Hydro Blender-Cyclone - Sprayerd with caustic coming from Gr/ ## R9 Tenportive - 95° Before Boiling Point ## Keep Ra AT 2 ## CHARGES - Charges - All ne neutral, Anionic. - LPI, LPZ-Cover Acrylic Acid bives anorge. - Acrylamide-Neutral. - Cuostic- LP3 Gives charge. - Acetic - Keep anideity tow. ## REDOX 2 - Versenex - Ro water? - TB HP / Pursatele purification process, contains no minerais therefore catalyst will not be able to react. - Moltrs SALT ## SALT concentrarion - 1. Obtain 500 mL Beaver from Lab, place on scale zero out. - 2. Tave Beaver to storage tank Flush line for 5 seconds. - 3. Get sample of 500mL exactly. - 4. Weigh on Scale the ! by 500 to get specific Gravity use onart to determine Soloution. ## LP1/LP2 - Process water - Acrylamide (3) - Urea - ATN - Acrylicacid - Caustic - D-Tonk -2°C - SAIT - ATN - Sparges (4) - HS - TRX - ARX - GH - GRI - 28-30% cyclones - 13 - Evaparative - PADDIE - 10-12010 - 52 - Diffusional - Paddle 2soas - 9-1090 - 53 is - Cooling - Pa dole - OS - TS - AK - 30min.MBA-Branching agert - Bomin-Verzo - Thermocatan, It - atomizer 3min-versres - CIEX Chelating agent - HGR) - Transfer - Fons 2 - BR - 5min-Hypo - chevinTranspar - agent - cmolecular weight) - 5mi-VA044 - Thermo Catanut - CBridge redox - Catalyst to - vazo7 - 5min-Persu fak - 30sec-TBHP - oxidier - imin monrs - Salt - Initiater ## LP3 - WATer - acrylamide - urea - aceticacid - D-Tank - glyou! (4) - ghycol - OUT - Caustic - -2°C - SAIT - ATN - VE- Fan - NI-Screw - 5- Dryer - M-MOTO - GR-Granulator - - Cyclone - Cyclone - - Centrifugal - Pump - SI Evoperate - Padole - FM - 42,516 - C4D - 3,4,7,8 - RX - 040 - Sparges 01-0 - osorges - PG - 12-15010 - diffusional - 52 - Fluidized - T - V1-5 - 1-5 - SU - Connection - Screw VI - 11010 - Cooling - 53 - Fluidized - శరీరధర - VS VI7 - GRI - atomizer ClEx - GAI - Trans for - -Fons 2 - Vecoustic - 2/2 - hars - Ra - 25,000m - KG - 3335 - added - 32 - 00 - 4screwsTronster srow - GRZ - Nomizer - CBEX - BRI - BR2 - GRZ - Transfer - Fon 2 ## Reaction curve Polymerization Steps - Initiation - occurs when the reducer from the redox pacмаде is added to monomer Sulontien - Propagation - Absence of monomer - Thermal catalyst and chain transfer agent drive the propagation Step - Termination - Last Freeradion is d or out of monomer ## Hydrometer - is used to measure the oil concentration (8). - Screen for GRI in LP3 thpal is 10 microns /6 microns for LPIHILPZ. ## Crystalization Unit - PSM- Sign in Sheet any contractar wonikor not normar work area. - Clipboard on Table -Fon Suckingrapers to scrubber. - Scrubber- captures ammonia from M1, R9, GRZ, Dryer I vent goes in to Sarvar. - ammonia- High Pit ,volutie gas low Pit Soloution captures / ammonia recirculates, through demister screate ran Showers. - ammonia Sulfate Soloution - Water droplets captures amoniori a vapors knockdow to Bottam of Scrubber & Suitric acid. - Density in Scrubber Soloution reacres 1.19-1.21 transters to Slurry, after outside operator creces PH Tank ## 2 Slurry Tanks - 60 Tronsters Slurry to Mother licuer Tonv - 85010 33,000 KGS - Manual PH Slurry and mother licuer Tent - Catena Sompte, Chek PH, Add ammonium Hydroxide as needed to achieve PH of G6.0-7.0 - Every addithion to mother livrer Tenu do a water Purge. - On Slurry tank Page, flusnes slury tank to mother I our term Runs process water will push any additional ammoniom Hydroxide / slurry into Mother vicwer. - Check P ## After Motherlicher tem, it Crystalizing - Send to crystalior, it not send to frace tarn to load into trouch. ## OIL - 6010-LPA - 25.90 - 52.75 - 1090-12010-PK 455 - CIEX-Granulator OIL Tank ↓ - C2-Screw Lubrication on Tank 60,30,10 - C3 Ex- Post Hydro Oil Tank ## Hypo - 20 mililiters in vazo pot of Span 80/ tueen - Slower reaction Corve indicate higher mypo weight - Faster reaction curve indicate lower mypo wight - Higher Hypo rower Molecular weight - Lower Hypo Higher molecular weight - Viscosity-measurement of the thickness of a Solution whion correlates to a pongmer molecular weight ## Why doritt we want reaction to take off too fast? ==End of OCR for page 24==