高濃度塩化ビニル脱塩素技術の開発

Abstract

To utilize waste polyvinyl chloride (PVC), the removal of chlorine in PVC has been studied by newly designed rotary kiln. Coarse coke was simultaneously supplied to prevent an agglomeration of PVC particle and sticking to an inner wall of kiln during PVC dechlorination reaction. The heat for dechlorination was supplied from the outer tube of the rotary kiln so as to minimize the amount of processed gas containing HCl. Basically, it was verified that this rotary kiln could be smoothly operated due to the presence of coke particle. It was observed that dechlorinated residue was a porous materials formed along with the removal of HCl and was coated with coke particle. Dechlorination efficiency of PVC increased with an increase in the processing temperature and retention time in kiln. Dechlorination reaction of soft PVC was a little different from that of rigid PVC because of containing plasticizer in soft PVC. It was considered that plasticizer in soft PVC was inhibited dechlorination reaction. From the above results, it was concluded that an optimum reaction conditions to give 95% of dechlorination efficiency were the processing temperature of 350°C, the retention time of over 15min and the PVC/Coke weight ratio of 1.0. Yield of the dechlorinated residue for the use of blast furnace was 40% for rigid PVC and 20 to 40% for soft PVC. It was estimated that the application of this process enable to utilize effectively industrial and municipal waste plastics containing PVC in the blast furnace.