Catalytic co-pyrolysis of waste vegetable oil and high density polyethylene for hydrocarbon fuel production

In this study, a ZrO2-based polycrystalline ceramic foam catalyst was prepared and used in catalytic co-pyrolysis of waste vegetable oil and high density polyethylene (HDPE) for hydrocarbon fuel production. The effects of pyrolysis temperature, catalyst dosage, and HDPE to waste vegetable oil ratio on the product distribution and hydrocarbon fuel composition were examined. Experimental results indicate that the maximum hydrocarbon fuel yield of 63.1 wt. % was obtained at 430 °C, and the oxygenates were rarely detected in the hydrocarbon fuel. The hydrocarbon fuel yield increased when the catalyst was used. At the catalyst dosage of 15 wt.%, the proportion of alkanes in the hydrocarbon fuel reached 97.85 wt.%, which greatly simplified the fuel composition and improved the fuel quality. With the augment of HDPE to waste vegetable oil ratio, the hydrocarbon fuel yield monotonously increased. At the HDPE to waste vegetable oil ratio of 1:1, the maximum proportion (97.85 wt.%) of alkanes was obtained. Moreover, the properties of hydrocarbon fuel were superior to biodiesel and 0# diesel due to higher calorific value, better low-temperature low fluidity, and lower density and viscosity.