Acid-modified phonolite and foamed zeolite as supports for NiW catalysts for deoxygenation of waste rendering fat

Abstract

Acid-modified phonolite material, Al2O3/foam zeolite and foam zeolite were used as supports for NiW catalysts. The zeolite type materials were prepared by a novel procedure from natural clinoptilolite. Phonolite materials were loaded with 5, 7.5 and 10 wt% of Ni containing 10, 7.5 and 5 wt% of W. Al2O3/foam zeolite contained 4 and 13 wt% of Ni and W and pure foamed zeolite was effectively loaded with 5 and 16 wt% of Ni and W. NiW/Al2O3 catalyst (3 wt% Ni and 11 wt% of W) was used for comparison of catalytic properties of synthesized materials. Catalytic tests were carried out in an autoclave pressurized at 7 MPa (H2) at room temperature and then heated to 365 °C for 1 h. Catalysts were characterized by N2 physisorption, XRD, XRF, NH3-TPD, CO2-TPD and H2-TPR. Catalyst properties were compared for the HDO of rendering fat into hydrocarbons. The liquid products were analyzed by simulated distillation, C, H, N, S elemental analysis, ATR and density (15 °C). Gaseous products were characterized by RGA-GC. Used catalysts were also analyzed by N2-TGA and O2-TGA. Novel phonolite modified solids and NiW/foam zeolite type materials were tested for the first time as catalysts being in some cases more active than NiW/Al2O3 material. Ni(5%)W(10%)/Acid phonolite and NiW/Foamed Zeolite resulted to be the most active materials for the HDO and hydrocracking reactions. The lowest amount of carbonaceous species on the surface of tested catalyst was found for the Ni(5%)W(10%)/Acid phonolite solid.