Comparison of activity and stability of supported Ni₂P and Pt catalysts in the hydroprocessing of palm oil into normal paraffins

초록

The hydroprocessing of vegetable oils into normal paraffins is a very promising method for producing green diesel and bio-jet fuels. However, detailed variations in the product distribution and catalyst deactivation have been rarely reported. In this study, the conversion of commercial palm oil over supported Pt and Ni2P catalysts is investigated. Activity tests conducted at 380 degrees C and 400 degrees C indicate that 10 wt.% Ni2P/SiO2 and 1 wt.% Pt/Al2O3 are more active and stable among the tested catalysts. An additional test at 360 degrees C revealed the superior hydroprocessing activity of the former catalyst. The major contributors to the activity variation of 1 wt.% Pt/Al2O3 are Pt sintering and a carbon deposit, resulting in a decrease in the Pt sites favoring decarbonylation and decarboxylation pathways. In contrast, the catalytic performance of 10 wt.% Ni2P/SiO2 is associated with an extremely low formation of carbon deposits and the Bronsted acidity responsible for the hydrodeoxygenation pathway, despite the transformation of Ni2P particles. Consequently, Ni2P/SiO2 turns out to be the most excellent among the tested catalysts for the hydroprocessing of palm oil.

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