Carbon nanotubes production from real-world waste plastics and the pyrolysis behaviour

[Display omitted] •RWWP-1,2,5,6 achieved a greater pyrolysis performance than RWWP-3,4.•The activation energy for RWWP ranged from 131.04 kJ mol−1 to 171.04 kJ mol−1.•RWWP samples could be identified by Py-TG/MS: PS, PE, PET, PP.•High-value CNTs can be obtained from RWWP-1,2,5,6 by catalytic pyrolysis process.•The carbon yield and CNTs purity top at 32.21 wt% (RWWP-1) and 93.04 % (RWWP-2). The investigation of the pyrolysis behaviour of real-world waste plastics (RWWP) and using them as the feedstock to produce carbon nanotubes (CNTs) could serve as an effective solution to address the global waste plastics catastrophe. This research aimed to characterize the pyrolysis behaviour of RWWP via thermogravimetric analysis (TG) and fast pyrolysis-TG/mass spectrometry (Py-TG/MS) analyses. Activation energies (131.04 kJ mol−1 –171.04 kJ mol−1) for RWWP pyrolysis were calculated by three methods: Flynn-Wall-Ozawa (FWO) method, Kissinger-Akahira-Sunose (KAS) method, and Starink method. Py-TG/MS results indicated that the RWWP could be identified as polystyrene (RWWP-1), polyethylene (RWWP-2), polyethylene terephthalate (RWWP-3, 4), and polypropylene (RWWP-5, 6). In addition, RWWP-1, 2, 5, 6 outperform RWWP-3 and 4 as sources of carbon for producing CNTs. The results showed a high carbon yield of 32.21 wt% and a high degree of CNT purity at 93.04%.