Inhibitor to stop polymerization of Chloroprene in EDC-VCM Colum

[muddassir.saleem]

Hi there,

We are currently looking for inhibitor to stop free radical polymerization of Chloroprene in our EDC-VCM systems.
The following is the problem:

1. during the shutdown, we found severe chloroprene choking in the light end's column, the overhead line, the reflux, line and in reflux drum.
2. As the chloroprene exits the top of the column in the overhead line, it condenses in the cool spots and begins to polymerize. This polymerization will continue through the length of the overhead line and into the condenser. As the chloroprene condenses and flows as line, and tha liquid from the condenser to the accumulator, reflux pump, and eventually back into the top of the column, it may continue to polymerize.

Does someone know potential inhibitors (Toluene-free) that can stop such polymerization to avoid fouling and contamination in the systems?

 

[georgeverghese]

Think you need to reduce your VCM cracker radiant section exit temp < 500degC to minimise chloroprene formation.
This company claims to have polymerisation inhibitors for your EDC purification light ends column overheads - see page 4

https://cdn.nufarm.com/wp-content/uploads/sites/26/2018/08/20074233/Nufarm-Inhibitors-for-the-Ethylene-Train.pdf

 

[muddassir.saleem]

Thanks for suggestion. Could you please elaborate related to radiant section exit temp ? I'd love to know all details.
Regarding inhibitors, we are already in talks with them.

I'm a fresh Engineer graduate and currently not part of EDC-VCM Column. I primarily see procurement and likely would be in process sometimes later.

Thanks

 

[georgeverghese]

As with many chemical reactions, rates for undesirable side reactions also increase with increasing temperature, ie selectivity for the desired product decreases with increasing temperature, even as conversion % for desired product increases. From what I can gather, conversion % for EDC is to be limited to <50% at 500degC in order to keep rates and composition of undesirable components such as chloroprene low.

See if this suffices as a brief introduction to this problem:

Coke formation in EDC cracker. Vinyl Chloride Monomer Process

COKE FORMATION INTO EDC CRACKER IN VINYL CHLORIDE PLANTS VCM (Vinyl Chloride) is produced in furnace crackers where EDC (Ethylene Dichloride) is fed to break the molecule to generate vinyl monomer and hydrogen chloride. Diagram 1 Balanced VCM Process The chemical reaction occurs as follows: ClCH2 -C

www.linkedin.com

See if BASF or Hoechst or Bayer have these polymerisation inhibitors also