Sustainable production of hydrogen and carbon nanotubes/nanofibers from plastic waste through microwave degradation

Abstract

Plastic waste pyrolysis to clean energy (H2) and valuable carbon nanotubes or nanofibers (CNTs/CNFs) is the most promising waste management and energy regeneration process. In this study, microwave-mediated single-step pyrolysis is used to produce COx-free hydrogen and CNTs/CNFs from real-world plastic films. Nickel, iron, and cobalt-based catalysts were prepared by the incipient wet-impregnation method and tested for real-world polyethylene plastic film degradation. In addition, the quality of CNTs produced and hydrogen yield were also compared for these catalysts. Various characterization tools were used to characterize the calcined catalysts, spent catalysts, and CNTs. Further, the effect of temperature ramp rate on hydrogen yield and CNTs properties was also analyzed. The results show that the iron-based catalyst produces a high yield of hydrogen and low-diameter and uniform-quality CNTs compared to other catalysts.