2023 Volume 109 Issue 9 Pages 728-737
Used plastic waste flowing into ocean has become a worldwide problem. In recent years international trade in used waste plastics has been regulated. Therefore, a large amount of used plastic should be disposed domestically. On the other hand, used waste plastics with high calorific value could be used as an energy source. Then a gasification process of used plastics using fluidized bed has been newly developed. In this process, used plastics were decomposed in a fluidized bed reactor at around 600°C which was lower temperature than that used in current commercial processes. Higher calorific value gas could be attained by a gasification reaction control at the lower temperature. Hydrogen enriched gas generated from the water gas shift reaction of the basic oxygen furnace gas was used as fluidizing, or gasifying agent since hydrogen was considered to have an effect for promoting the decomposition reaction of hydrocarbon in used plastics. As fluid medium in the reactor, catalysts were used to improve gasification efficiency. In this study, the effect of gasification temperature and the type of the catalyst on a calorific value of produced gas and a gasification efficiency were investigated. High calorific value gas (LHV: 5000 kcal/Nm3) could be successfully produced from pyrolysis of used plastics by appropriate gasification temperature and catalyst.
