Catalytic fast pyrolysis of high-density polyethylene waste [in Ukrainian]

Given the rapid increase in polymer waste volumes and the limited availability of traditional energy resources, the search for efficient polymer disposal technologies capable of generating valuable products has become highly relevant. One such method is catalytic pyrolysis—a thermochemical decomposition process of organic materials in the absence of oxygen, which enables the conversion of plastic waste into liquid and gaseous fuel products. The use of catalysts in the pyrolysis process allows for the optimization of reaction temperature conditions and influences the composition of the resulting products. High-density polyethylene (HDPE), widely used in packaging and household applications, is one of the primary components of polymer waste and holds significant potential for recycling through this method. The article demonstrates and substantiates the feasibility of processing HDPE via catalytic pyrolysis to produce alternative energy sources, such as synthetic oil, pyrolysis gases, and pyrocarbon. The thermodestruction of HDPE waste was studied in a batch reactor under oxygen-free conditions using various catalysts (Ni/MgO, Fe₂O₃, Ni/CaO, Fe₃O₄, ascarite, and HY) and without them. It was found that fast catalytic pyrolysis in the temperature range up to 450 °C promotes an increased yield of liquid hydrocarbons, particularly synthetic oil, as well as an improved composition of the resulting gases. Gas chromatography analysis of the pyrolysis products revealed a significant proportion of saturated hydrocarbons. The use of catalysts was also found to reduce the amount of solid residue and increase the yield of the gas mixture.