Influence of nickel-based catalysts on syngas production from carbon dioxide reforming of waste high density polyethylene

Abstract

Syngas production (H2 and CO) from carbon dioxide reforming of high density polyethylene (HDPE) over Ni–Al catalyst was evaluated in a two-stage fixed bed reactor. Syngas production was favoured by CO2 addition, with the highest production of 138.81mmolsyngasg−1HDPE, which was about six times higher than non-catalytic, non-CO2 addition. The catalytic performances of nickel-based catalysts with different promoter metals (Cu, Mg and Co) in the CO2 reforming of HDPE were also studied. It was found that Ni–Co–Al had an excellent anti-coking performance, with no detectable formation of coke on the catalyst surface. Moreover, the syngas production was significantly improved by the addition of Co compared to the Cu and Mg metal promoters. The CO2 conversion for Ni–Co–Al catalyst was also the highest at 57.62%. Further investigation of the effect of Co concentration on CO2 reforming of HDPE showed that the higher Co content, the higher the syngas production and CO2 conversion.