The effect of plastic addition on coal caking properties

Abstract

The process of recycling waste plastics using coke oven was studied. The effect of plastic addition on coal caking properties was investigated. Thermal decomposition products of plastics interacted with coal during carbonization and the effect of plastic addition on coal caking property varied for various kinds of plastics. The addition of polyethylene, polypropylene, and PVC had little effect on coal caking property and coke strength, while the addition of polystyrene, polyethylene terephthalate (PET), and terephthalic acid decreased the maximum fluidity and total dilatation and deteriorated the coke strength. These differences were explained by the interaction between thermally decomposed products from plastics and coal. It is suggested that the radical formed as a result of polystyrene or PET thermal decomposition may remove hydrogen from coal, resulting in the decrease of coal caking property.