Influence of Polyethylene Terephthalate and Additive Effect of Converter Dust during Liquefaction of Waste Plastics

Abstract

Dechlorination of PVC is indispensable for liquefaction of chlorine-containing waste plastics (CCWP). Therefore, the following process was investigated: converter dust (CD) and the heavy oil bottom component of coal tar (HOB) were mixed with CCWP and melted at 250 °C to form iron chloride. A hot water process was performed at 250 °C to extract the iron chloride. Afterwards, the hydrocracking of the mixture of plastics and HOB was performed at 400-450 °C to generate the light oil. However, the amount of polyethylene terephthalate (PET) in waste plastics is increasing every year. Therefore, it is necessary to clarify additive effect of CD in the presence of PET. Moreover, a portion of CD added in excess during the melt process is expected to act as a catalyst for the hydrocracking. The results indicated that the formation of the iron chloride and the generation of chlorinated hydrocarbons occurred competing in the presence of PET. However, the hot water process was performed after the melt process so that the chlorine contained in the chlorinated hydrocarbons and the iron chloride can be removed. In addition, it was confirmed that CD exhibited catalytic activity for the hydrocracking of the mixture of plastics and HOB.