Effect of reducing catalyst coke by La loading in hydrocracking of Jatropha oil

Abstract

In order to assess the La effect on reducing carbonaceous deposition (coke) on catalysts for the hydrocracking of Jatropha oil, NiW/nHA, NiW/Al₂O₃ and NiW/HY catalysts modified with loaded La were synthesized and studied. The catalysts were characterized by N₂ adsorption–desorption, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of ammonia (NH₃-TPD), temperature programmed desorption of hydrogen (TPD-H_ads), and temperature-programmed desorption of carbon dioxide (CO₂-TPD). The species and the amount of coke on the hydrocracking catalyst were measured by Fourier transform infrared (FT-IR) spectroscopy, solid state ¹³C nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA), demonstrating that the coke was constituted of polyaromatic hydrocarbons and that the La catalyst loading had a very positive effect on coke reduction. The amount of coke on NiW/nHA, NiW/Al₂O₃ and NiW/HY catalysts decreased respectively by 0.94%, 1.19%, 1.91% after 8 h and 1.66%, 1.89%, 3.78% after 180 h. The catalytic stability and the catalyst lifetime were also improved by La loading.