An advanced process removes residual vinyl chloride monomer (VCM) entrapped in aqueous polyvinyl chloride (PVC) slurries. Not only is the VCM recovered for recycle, but VCM emissions from PVC slurry processing and drying are drastically reduced. This process has exceeded expectations in terms of VCM removal efficiency, product quality and plant operability, while requiring lower than anticipated energy input.
While the concept of steam stripping VCM from PVC is not new, the advances made by the company's technology involve specialized compact equipment and operational know-how that prevent heat degradation of PVC. VCM content of homopolymers or copolymers of vinyl chloride can be reduced to less than 1 ppm levels. The process is continuous and can be totally automated, making it a very attractive addition to existing PVC plants.
Advantages of Chisso VCM Removal Process
High Efficiency
below 1 ppm of residual VCM without degradation of PVC.
Increase Productivity of Reactor
reduced polymerization cycle.
No Quality Problem
no significant change of PVC quality after stripping
Closed System
all VCM can be recovered and reused without any leakage.
Low Consumption of Energy
less than 130 kg steam per ton of PVC.
Maintenance Free
without opening of column
No Additional Manpower & Easy to Change Grade
automatic system
Compact Design
small area requirement and low investment.
This process has been adopted under license from Chisso by other PVC producers in Japan, Asia, Europe and North and South America. At present more than one hundred (100) commercial units with more than 6 million tpy of total capacity are in operation with satisfactory results. Currently, Chisso also offers the new VCM removal process for emulsion PVC process.
