Реферат: The search for new active hydrotreating catalysts is one of the stratergies of R&D branches in modern companies. Ni2P containing catalysts were shown to have higher activity in hydrodesulphurization, hydrodenitrogenation and hydrogenation. But most of the works are made using model compounds and powder catalysts. There is no study of Ni-phosphide catlaysts supported on granulated Al2O3. The aim of this work is to study preparation of granulated Ni-phosphide catalysts and their catalytic activity in hydrotreating of straight run gas oil. The catalysts were prepared by incipient wetness impregnation of granulated Al2O3 (SBET = 215 m2/g, Dp = 103 Å, Vp = 0.56 cm3/g). Two different methods were used to prepare the catalysts – temperature-programmed reduction (TPR) and temperature-programmed phosphidation (TPP). For TPR phosphite (Ni(OH)2 and H3PO3 – I) or hypophosphite (Ni(NO3)2 and H3PO2 – H) were used as precursors. After impregnation the samples were dried and reduced in situ in catalytic reactor at 400–600 °C. For TPP Al2O3 was impregnated by aqueous solution of Ni(NO3)2 dried and calcined at 400 °C, reduced to Ni/Al2O3 at 400 °C in hydrogen flow and phosphidized by PPh3 in hydrogenated gas oil at 380 °C. Straight run gas oil (sulfur content = 7740 ppm, nitrogen content = 116 ppm) hydroprocessing was carried out in continious flow fixed bed reactor at 340 °C, 4 MPa, LHSV = 1,5 h–1. According to XRD results TPR method allowed us to obtain Ni12P5 phase after reduction at 600 °C (DXRD<3 nm). Catalysts prepared by TPP method contained Ni2P phase (DXRD=7.5 nm). TEM analysis showed broad distribution for TPR samples (5–20 nm) and narrower distribution for TPP samples (DTEM=3.4 nm). The beneficial effect of decreasing reduction temperature and using TPR method was found. Nevertheless, all samples showed relatively low activity in hydrodesulfurization – sulfur content after reaction was 2400–4500 ppm (Figure 1, for NiMoS catalysts it is about 50–60 ppm). In hydrodenitrogenation the activity was quite high – 3–7 ppm of nitrogen after reaction.

Библиографическая ссылка: Shamanaev I.V. , Suvorova A.O. , Gerasimov E.Y. , Pakharukova V.P. , Bukhtiyarova G.A.
Comparative Study of Ni-Phosphide Catalysts Supported on Granulated Al2O3 in Hydrotreating of Straight Run Gas Oil
IV Scientific-Technological Symposium "Catalytic Hydroprocessing in Oil Refining" 26-30 Apr 2021