Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 95 === This work was to optimize the vinyl chloride monomer(VCM)stripping operation of the bulk polymerization process of Polyvinyl chloride (PVC) for the deduction of the residual VCM from PVC powders. Past operating records were first evaluated to find the critical parameters, jacket temperature, heating time and the amount of steam injected. A series of experiments were then conducted on the commercial production unit; and finally optimal results subject to constraints of process conditions were evaluated using multi-regression and response surface methodologies.
Experimental results showed that the residual VCM level could be maintained below 8 ppm, when the temperature of jacket was controlled 95 oC, the heating time between 80~110 minutes, and the steam injection between 90~110 kg /per ton PVC; however, the color became faintly reddish and the thermal stability became worse. Higher temperature over 100℃ could reduce VCM to a level below 5 ppm and also darkened the color. More stabilizers had to be added to overcome the problems. Future work will focus on improving the thermal stability and the color of PVC powders.
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