Verification of PVC dechlorination process based on 1,000 t/y semi-commercial plant operation

摘要

A dechlorination process to utilize poly(vinyk chloride) (PVC) in ironmaking has been developed in a 1,000 t/y semi-commercial facility with a newly designed indirect heating rotary kiln. In this process, coarse coke was suppliedto prevent agglomeration of PVC particles and adhesion to the inner wall of the kiln during PVC dechlorination. A dechlorination efficiency of over 95% was attained at a processing temperature of 325 deg C and a retention time of 30 min. In addition to HCl, C_1-C_4 hydrocarbons, benzene and tar were generated by PVC pyrolysis. The content of these by-products was less then 3% under the conditions of 95% dechlorination efficiency, although it increased slightly with an increase in processing temperature and retention time of PVC. The supply of coarse coke with PVC was also fund to be effective in promoting heat transfer to the PVC layer in the kiln. The results obtained in the 1,000 t/y semi-commercial plants, it was verified that this dechlorination process could be smoothly operated due to the coke particles. It can be concluded that this process contributes to the favorable recycling of waste PVC.