Methods to prevent self-polymerization in recycled monomer storage tanks
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The self-polymerization of vinyl chloride not only blocks pipes and affects product quality, but also poses serious safety hazards. It is said that there have been cases abroad of explosions caused by the self-polymerization of vinyl chloride inside gas holders. Methods to prevent the self-polymerization of recycled monomers: 1. Add ammonia water to the storage tank to adjust the pH of the monomer to 0.1PPm ； 2. Add the polymerization inhibitor hydroquinone (10PPm) at the water ring compressor. Using self-pressure recovery, it can be directly added to the storage tank. Both ammonia and hydroquinone are soluble in water, and they can be separated during wastewater discharge. (The above is Acoma’s method; those who wish to try it are invited to reply and discuss.)
We add alkali to the working water in the water ring compressor to make it alkaline, thereby destroying residual additives and eliminating decomposed HCL
“Could \"adding alkali\" cause electrochemical corrosion to the compressor rotor?
1. Add alkali to the storage tank to adjust the pH of the monomer. 2. Add the inhibitor hydroquinone to the storage tank. 3. Reduce the residence time of the monomer in the storage tank.
The water in water ring compressors should have its pH value adjusted with alkali to ensure the proper operation of the system and the quality of the monomers.
This post was last edited by wang*neng on 2009-6-8 10:04: add alkali and inhibitor. It’s all done after the fact; I believe the main reason for self-agglomeration is the presence of water in the monomer: 1. Remove as much water as possible from the monomer by using effective mist removers; 2. Modify the existing freeze-drying process. 3. The polymeric recycled vinyl chloride is stored in a separate gas tank.
Adding the anti-polymerization agent nonylphenol is the most effective method, but it should not be used in excessive amounts, as this can affect the polymerization process.
Add an alkali scrubber before the recycled monomer inlet cabinet.
Too much initiator cannot be added; use a separate gas tank for recovery!
In addition to the above measures, 1) it is necessary to prevent materials (mainly foam) from entering the monomer recovery system, as these materials contain large amounts of active substances; therefore, an antifoaming agent can be added after the polymerization reaction is completed to prevent foam formation during the discharge process； 2. In the recovery system, washing measures are taken for the vinyl chloride medium to wash away the active substances ； 3. The moisture content of the monomer should be reduced to the greatest extent possible. A pre-cooler can be installed to condense the moisture first. Then enhance the system’s drainage operation to remove water from the system promptly.