Jet fuel production from waste plastics via catalytic pyrolysis with activated carbons

Abstract

With the increasing amount of waste plastics being used domestically and industrially, the disposition of those being not reusable is a challenging task. Herein, the catalytic pyrolysis of waste plastics over seven types of commercial and home-made activated carbons was studied in a facile tube reactor. A central composite experimental design was further adapted to optimize the reaction conditions and up to 100 area% of the obtained liquid components belonged to jet fuel-ranged hydrocarbons, in which alkanes and aromatics accounted for 71.8% and 28.2%, respectively. Experiment results revealed that these activated carbons although generated via various physical and chemical activation processes could all exhibited excellent catalytic performance in converting low-density polyethylene into jet fuel and H2-enriched gases. Properties of activated carbons were also characterized by scanning electron microscope, Fourier transform infrared spectrometer, nitrogen gas adsorption, and chemical adsorption. It can be concluded that the acidity was a critical factor in determining the catalyst activity, where jet fuel-ranged alkanes and aromatics were favored by using activated carbons of weak and relevant strong acidity, respectively. Rising catalytic reaction temperature could enhance the aromatization of alkanes to increase the percentage of aromatics and release more hydrogen molecules. In addition, the production of jet fuel was also achieved from daily waste plastics, which was also confirmed by nuclear magnetic resonance analysis. The present work offers a novel route of converting waste plastics directly into transportation jet fuel.