Study on catalytic pyrolysis and combustion characteristics of waste cable sheath with crosslinked polyethylene

With the progress of power grid system development, the coverage area of cable is more and more wide, and the problem of yearly increasing waste cable has gradually affected our daily life. Polyethylene (PE) is the main material source of cable sheath. Through the study of its pyrolysis behavior, it is not only beneficial to solve the accumulation of waste cable, but also can be used in the recycling of waste PE plastic. In this work, the percentage of PE and catalyst including H-Zeolite Standard Oil Corporation of New York (Socony) Mobil-Five (HZSM-5), H-ultra-stable Y zeolite (HUSY) or Mobil Composition of Matters-41 (MCM-41) blend was controlled at 70:30 wt:wt to make the composite, and the mixture samples were studied by using a self-developed tubular furnace reactor-mass spectrometer (MS) experimental platform at the temperature from 300 to 700 degrees C. It was found that HZSM-5 was the most suitable and efficient catalyst among the three types, and a new pyrolysis path was also obtained according to the experimental results to explain the unusual phenomena, and a new method for catalytic pyrolysis of PE was provided. In addition, considering that the cable sheath was prone to ignite during pyrolysis, this work also evaluated its thermal hazard by cone calorimeter. The addition of catalyst changed the ignition time and heating rate, but it did not affect the flame temperature. Meanwhile, PE with MCM-41 catalyst showed excellent fire safety performance. Through principal component analysis (PCA), catalyst type was the main influencing factor. This work is of guiding significance to PE pyrolysis and combustion experiments in the future and provides reference and basis for recycling process design of waste cable sheath and plastics.