Polyol Unit
Polyol production = 16,000 MT/PA
Products: Nine polyols and Ten premix formulations.
Polymer Inrermediates:
St...
Chemistry:
Initiation: Addition of KOH to glycerine
C3H8O3 + KOH  C3H5(OH)2OK+ + H2O
Removal of water for efficient polyo...
Raw material specification:
1) Propylene Oxide
2) Ethylene Oxide
3) Starters: Glycerine/Triethanolamine
4) Potassium Hydro...
Prepolymer thus formed is allowed to soak for a certain time in the
reactor and then send to storage tank.
Prepolymer Stor...
Dimineralised water and antioxidants are also added to the treater. By
using filter aid, the polyols is then separated fro...
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Polyol Unit

Published on: Mar 4, 2016
Source: www.slideshare.net


Transcripts - Polyol Unit

  • 1. Polyol Unit Polyol production = 16,000 MT/PA Products: Nine polyols and Ten premix formulations. Polymer Inrermediates: Starter: Glycerine, dipropylene glycol, sucrose Initiator: Dried KOH Prepolymer or Base: Low Molecular weight Polymer, Intermediates from Initiators & various EO/PO mixtures. HMW prepolymer: For manufacturing polyols above 4200 MW Crude polyol: Polyol before potassium removal and stripping.
  • 2. Chemistry: Initiation: Addition of KOH to glycerine C3H8O3 + KOH  C3H5(OH)2OK+ + H2O Removal of water for efficient polyol was preferred. Impurity of polyols were removed as unsaturates. C3H6O(propylene oxide) Allyl Alcohol Allyl Alcohol+m(PO)  Monol Factors Affecting production: Ethylene oxide, Propylene Oxide, Activated Glycerine & Unsaturated level of final product polyols. Polyol molecular weight is inversely proportional to polyol product hydroxyl number. Low functionality leads to unsaturation due to isomerisation of Propylene Oxide. Crude containing Alkoxide (ROK+H2O  ROH+KOH) were removed by hydrolysing were sodium pyrophosphate were used to remove potassium.
  • 3. Raw material specification: 1) Propylene Oxide 2) Ethylene Oxide 3) Starters: Glycerine/Triethanolamine 4) Potassium Hydroxide Process Theory: Glycerine is saponified with KOH and the initiator formed is treated with propylene oxide to form prepolymer. The prepolymer thus formed is treated with propylene oxide and/or ethylene oxide to form polyols mixture which is then separated from impurities by filtration to obtain the desired polyol product. Mix Drum: Glycerine is mixed with potassium hydroxide to form initiator in the mix drum which is provided with a vent. Reactor (Prepolymer Step): Then the initiator from mix drum is treated with propylene oxide in the reactor. This step is called as Prepolymer step.
  • 4. Prepolymer thus formed is allowed to soak for a certain time in the reactor and then send to storage tank. Prepolymer Storage: The prepolymer stored in storage tank is sent to the second reactor. A part of the prepolymer is sent to the mix drum for recatalysation. Reactor (Polymer Step): This reactor is also provided with a vent where propylene oxide and/or ethylene oxide is added for noncapped products. For capped products, an additional step is required where ethylene oxide is added after stripping unreacted propylene oxide in the reactor. Treater: Treater is used to remove KOH and unreacted oxides. It is also provided with a vent. The polyols mixture formed in the reactor is sent to the treater where the KOH present in the mixture is neutralized by adding a neutralizer. Sodium phrophospate powder is used as neutralizer.
  • 5. Dimineralised water and antioxidants are also added to the treater. By using filter aid, the polyols is then separated from other components and sent to day tanks for storage. Leaf type filtration is employed. Water washing is done to prevent cross contamination of the products. Vacuum System: Vacuum system is used for product types drying, stripping of PO and evacuating. Premix Formulations: Blend drums are used for agitation of polyol products. Internal and external agitation additive pots are used as the medium of agitation.

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