Processing real-world waste plastics by pyrolysis-reforming for hydrogen and high-value carbon nanotubes

Chunfei Wu, Mohamad A. Nahil, Norbert Miskolczi, Jun Huang, Paul T. Williams

Research output: Contribution to journalArticle

68 Citations (Scopus)

Abstract

Producing both hydrogen and high-value carbon nanotubes (CNTs) derived from waste plastics is reported here using a pyrolysis-reforming technology comprising a two-stage reaction system, in the presence of steam and a Ni-Mn-Al catalyst. The waste plastics consisted of plastics from a motor oil container (MOC), commercial waste high density polyethylene (HDPE) and regranulated HDPE waste containing polyvinyl chloride (PVC). The results show that hydrogen can be produced from the pyrolysis-reforming process, but also carbon nanotubes are formed on the catalyst. However, the content of 0.3 wt.% polyvinyl chloride in the waste HDPE (HDPE/PVC) has been shown to poison the catalyst and significantly reduce the quantity and purity of CNTs. The presence of sulfur has shown less influence on the production of CNTs in terms of quantity and CNT morphologies. Around 94.4 mmol H2 g-1 plastic was obtained for the pyrolysis-reforming of HDPE waste in the presence of the Ni-Mn-Al catalyst and steam at a reforming temperature of 800 C. The addition of steam in the process results in an increase of hydrogen production and reduction of carbon yield; in addition, the defects of CNTs, for example, edge dislocations were found to be increased with the introduction of steam (from Raman analysis).

Original languageEnglish
Pages (from-to)819-826
Number of pages8
JournalEnvironmental Science and Technology
Volume48
Issue number1
DOIs
Publication statusPublished - Jan 7 2014

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ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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