Efect of pellet size on the steam reforming of phenol-pet waste to hydrogen producton over Ni/La-promoted Al2O3 catalyst

Abstract

The different loading of nickel oxide, the effect of the addition of Lanthanum (La) with Al2O3 support on the catalytic performance of Ni-based catalysts for selective hydrogen production from polyethylene terephthalate (PET) plastic waste via steam reforming process have been investigated. The catalysts were prepared by impregnation method and were characterized using BET, SEM, EDX, TPR-H2, TGA and DTA. The results showed that Ni-Laco- impregnated Al2O3 catalyst has excellent activity for the production of hydrogen with a prolong stability. The feed conversion of 88.53% was achieved over 10% Ni/Al2O3 catalyst which increased to 94.4% in the case of 10% Ni-5% La/Al2O3 catalysts with a H2 yield of 76.6%. The catalyst performance in term of gas production and feed conversion was investigated under various operating parameters, e.g., feed flow-rate, catalyst pellet size, and catalytic stability. It was found that the feed flow rate has negative effects on H2 yield and conversion, yet different pellet sizes has the adverse effects. The Ni particles, which are the noble-based active species are more effective, thus offered good hydrogen production in the PET steam reforming process. Incorporation of La as a promoter (or second metal) to the Ni/Al2O3 catalyst significantly increased catalyst reusability. The Ni-La/Al2O3 catalyst with bigger size showed remarkable activity even after 24 h along with the production of carbon nanotubes, while H2 yield and feed conversion was only slightly decreased.