BACKGROUND: One-stage hydroconversion of fatty-acid based feedstocks is a promising way to obtain high-quality fuels. This process is based on hydrodeoxygenation, isomerization and hydrocracking reactions. In this work, Ni2P/Al2O3-zeolite catalysts were synthesized and tested in hydroconversion of a model compound - methyl palmitate. RESULTS: Ni2P catalysts were prepared by in situ phosphidation of metallic Ni/Al2O3-zeolite precursors by PPh3. Mixtures of zeolite (30 wt%) and boehmite were peptized and extruded to obtain the support granules. SAPO-11, ZSM-5, ZSM-22, ZSM-23 and ZSM-12 were used as a zeolite component. The catalysts and supports were characterized by a range of physicochemical methods: chemical analysis (ICP-AES), low-temperature N-2 adsorption, H-2-temperature programmed reduction, NH3-temperature programmed desorption, Fourier transform infrared spectroscopy of adsorbed CO, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and Al-27 and P-31 magic angle spinning nuclear magnetic resonance. The catalysts were studied in methyl palmitate hydroconversion (one-stage hydrodeoxygenation-isomerization-hydrocracking) in a continuous-flow fixed bed reactor at 290-340 degrees C, 2 MPa, H-2/feed = 600 Ncm(3)/cm(3) and LHSV = 5.3 h(-1). SAPO-11 containing sample showed high selectivity to C15 and C16 iso-alkanes (63%, at 340 degrees C), and all ZSM-containing samples showed high selectivity to cracked C5-C9 products (55-100%, at 340 degrees C) with varying amounts of iso-alkanes (31-57%, at 340 degrees C). CONCLUSION: The results show that by choosing the zeolite component of the catalyst it is possible to finely tune product quality in the range from low-temperature diesel fuel to jet fuel or gasoline. (c) 2024 Society of Chemical Industry (SCI).

A series of bifunctional catalysts, MoS2/Al2O3 (70 wt.%), zeolite (30 wt.%) (zeolite—ZSM-5, ZSM-12, and ZSM-22), and silica aluminophosphate SAPO-11, were synthesized for hydroconversion of methyl palmitate (10 wt.% in dodecane) in a trickle-bed reactor. Mo loading was about 7 wt.%. Catalysts and supports were characterized by different physical-chemical methods (HRTEM-EDX, SEM-EDX, XRD, N2 physisorption, and FTIR spectroscopy). Hydroprocessing was performed at a temperature of 250–350 °C, hydrogen pressure of 3.0–5.0 MPa, liquid hourly space velocity (LHSV) of 36 h−1, and an H2/feed ratio of 600 Nm3/m3. Complete conversion of oxygen-containing compounds was achieved at 310 °C in the presence of MoS2/Al2O3-zeolite catalysts; the selectivity for the conversion of methyl palmitate via the ‘direct’ hydrodeoxygenation (HDO) route was over 85%. The yield of iso-alkanes gradually increases in order: MoS2/Al2O3 < MoS2/Al2O3-ZSM-12 < MoS2/Al2O3-ZSM-5 < MoS2/Al2O3-SAPO-11 < MoS2/Al2O3-ZSM-22. The sample MoS2/Al2O3-ZSM-22 demonstrated the highest yield of iso-alkanes (40%). The hydroisomerization activity of the catalysts was in good correlation with the concentration of Brønsted acid sites in the synthesized supports.

Herein, we present a new approach to the design of the catalysts for aerobic oxidation of sulfur-containing compounds. Iron-containing zeolite-based (ZSM-5, ZSM-12) catalysts were synthesized and successfully tested in oxidation of model mixtures as well as real petroleum fractions. The catalysts were characterized by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV/Vis), temperature programmed desorption of ammonia (NH3-TPD), and low-temperature nitrogen adsorption-desorption. Among these catalysts Fe-ZSM-12 demonstrated the best activity: exhaustive oxidation of dibenzothiophene (DBT) in the presence of this catalyst was achieved in 2 h at 150°C. Influence of the reaction conditions (temperature, amount of catalyst, and time) on the conversion of the model substrate was studied. It was shown that in the presence of Fe-ZSM-12 catalyst activation of molecular oxygen proceeds via formation of superoxide radical. Fe-ZSM-12 exhibited an excellent stability and retained its activity after 10 cycles of oxidation. Under optimal reaction conditions sulfur content in straight-run gasoline fraction was reduced from 807 to 43 ppm, in diesel fraction – from 1898 to 150 ppm. Two-dimensional GC-MS analysis of diesel fraction before and after desulfurization indicates high selectivity of the process. Possibility of sulfur dioxide formation during the aerobic oxidative desulfurization process was studied for the first time. The use of zeolite-based catalysts containing transition metals for aerobic oxidation of sulfur-containing compounds is a promising approach for clean fuel production.

A bizeolite catalyst based on ZSM-5 and ZSM-12 was designed to maximize the yield of valuable aromatics from ethylbenzene (EB) rich feedstocks for the first time. The catalyst Pt/ZSM-5:ZSM-12/Al2O3 was characterized by X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed desorption of ammonia (TPD-NH3), transmission and scanning electron microscopy (TEM and SEM), X-ray fluorescence analysis (XRF), Fourier-transformed infrared spectroscopy (FTIR) and Al-27 magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The catalyst and its components were tested in isomerization of an industrial C-8 aromatic cut (C8-Ar) and feedstocks with high EB content. The catalyst demonstrated higher conversion of EB and m- xylene (MX) compared with an industrial catalyst and higher selectivity to dealkylation products.