K.A. Nadeina

NiMo/USY-Alumina Catalysts with Different Zeolite Content for Vacuum Gas Oil Hydrocracking Over Stacked Beds

The stacked beds comprising hydrotreating catalyst as the top layer, hydrocracking catalyst based on amorphous silica-alumina as the interlayer and hydrocracking catalyst based on USY zeolite as the bottom layer were tested in hydrocracking of mixed feed containing straight-run VGO, heavy coker gas oil, aromatic extract and petrolatum. It is shown that stacked beds with developed catalysts can be successfully used both in the once-through hydrocracking to provide VGO conversion of 70–80% with middle distillates yields up to 50 wt% and in the first stage operation of two stages hydrocracker to provide 35–65% VGO conversion and produce high-quality middle distillates and feed for the second stage. The commercial partner of this work is Gazprom Neft PJSC (Gazprom Neft Omsk Refinery).

Hydrocracking of Vacuum Gasoil on NiMoW/AAS-Al 2 O 3 Trimetallic Catalysts: Effect of the W : Mo Ratio

The effect of the W: (W + Mo) atomic ratio in NiMoW trimetallic catalysts on their catalytic and physicochemical properties is studied. The catalysts are prepared by impregnating a carrier containing amorphous aluminosilicate (AAS) and aluminium oxide with an aqueous solution containing Ni, Mo, W compounds, and citric acid. They are studied via XRF, TEM, NH3 TPD, and low-temperature nitrogen adsorption and are tested in the hydrocracking of vacuum gasoil (VGO). The average length of a sulfide active component layer shrinks as the amount of Mo increases and the amount of W in the catalyst is reduced. XPS data indicate that the degree of sulfidation of tungsten in NiMoW trimetallic catalysts is lower than in NiW catalyst. Testing of the catalysts in hydrocracking of a straight-line VGO at 390–420°C, 16 MPa, a feedstock hourly space velocity (FHSV) of 0.71 h−1, and a H2: VGO ratio of 1200 L/L shows the activities of hydrodesulfurization, hydrodenitrogenation, hydrogenation, and hydrocracking grow along with the W: (W + Mo) ratio. When the process pressure is high and the amount of sulfur in the NiW feedstock is low, the catalysts have higher activity in the target reactions of VGO hydrocracking than NiMo catalyst.

Hydrocracking of Vacuum Gasoil on NiMo/AAS-Al 2 O 3 Catalysts Prepared from Citric Acid: Effect of the Catalyst Heat Treatment Temperature

Ni-Mo bimetallic catalysts are prepared by impregnating a carrier containing amorphous aluminosilicate (AAS) and aluminum oxide using a solution with Ni, Mo, and citric acid. The temperature of the catalysts ranges from 120 to 550°С. The physicochemical properties of the catalysts are studied via XPS, TEM, and HCNS analysis, and they are tested in hydrocracking of vacuum gasoil. The particles of the sulfide active component (NiMoS phase) are localized predominantly on surfaces of aluminum oxide, and only some are on surfaces of AAS. When the temperature of catalyst calcination is raised, the average number of the layers in particles of the NiMoS phase grows as well, due to the removal of citric acid. This indicates strengthening of the interaction between the sulfide active component and aluminum oxide. The content of Ni-Mo massive sulfide particles also grows along with the temperature of calcination. The morphological characteristics of the sulfide active component affect the activity of the catalysts in hydrodesulfurization and hydrodenitrogenation, but not in hydrocracking. The optimum heat treatment temperature for NiMo/AAS-Al2O3 catalysts prepared with citric acid is 120°C. Recommendations are given for the heat treatment of catalysts under industrial conditions.

Catalyst for selective hydrotreating of catalytic cracking gasoline without preliminary fractionation

A new CoMo catalyst for selective hydrotreating of FCC gasoline has been developed; the catalyst is intended for the production of hydrotreated gasoline with up to 10 ppm of sulfur and with a research octane number decreased by less than 1.0. The new catalyst allows hydrotreating of FCC gasoline without its preliminary separation into the light and heavy fractions. The hydrotreating conditions were as follows: hourly space velocity 2.2 h–1, temperature 270°C, pressure 2.5 MPa, H2/feed = 150 m3/m3. The high degree of hydrodesulfurization at minimum decrease in the octane number is achieved due to the high activity of the developed catalyst in hydrodesulfurization of the sulfur-containing components of the feedstock and conversion of reactive high-octane olefins of FCC gasoline into less reactive derivatives with high octane numbers. The catalyst is a CoMoS phase deposited on a support containing amorphous aluminosilicate and γ-Al2O3. The method for the preparation of the catalyst is adapted to the equipment of Russian plants and feedstocks. The parameters of hydrotreating using this catalyst ensure the hydrotreating of FCC gasoline to a residual sulfur content of less than 10 ppm with minimum redesign of the equipment currently available at Russian refineries.

Катализатор для селективной гидроочистки бензина каталитического крекинга без предварительного фракционирования

A new CoMo catalyst was developed for selective hydrotreatment of FCC gasoline to provide no more than 10 ppm of sulfur in the hydrotreated gasoline and no more than 1,0 point RON decrease against the initial RON. The new catalyst allows the FCC gasoline not to be prefractionated into light and heavy fractions before its hydrotreatment. The hydrotreatment conditions are as follows: feed flow rate 2,2 h–1, 270 °C, 2,5 MPa, H 2 /feed = 150 m 3 /m 3 . The high degree of hydrodesulfurization at a minimal decrease in RON is achieved owing to the high catalyst activity to hydrodesulfurization of the sulfur-containing components and to conversion of reactive high-octane olefins of the FCC gasoline to their less reactive derivatives with the high octane numbers. The catalyst is a CoMoS phase on the support containing amorphous aluminosilicate and γ-Al 2 O 3 . The method for the catalyst preparation is adapted to the Russian industrial facilities and to the feedstock available in Russia. Application of the hydrotreatment process based on this catalyst does not need considerable reconstruction of the facilities available at Russian refineries but provide residual sulfur content less than 10 ppm in the hydrotreated FCC gasoline.

Катализаторы и процессы селективной гидроочистки бензина каталитического крекинга

Content of catalytic cracking gasoline (GCC) in Russian blended gasoline is greater than 30 %. The most of sulfur in blended gasoline comes from GCC, while permitted sulfur content in commercial gasoline of Euro 5 standard is 10 ppm. High sulfur content of the GCC makes it impossible to use them without prior hydrotreating, inevitably reducing the octane number of gasoline. The nature of sulfur compounds that make the major contribution to the octane number was considered. An overview of modern technological processes and catalysts for hydrotreating of GCC was made. It was shown that modern gasoline desulfurization were based on pre-fractionation and separate purification of heavy and light fractions that made them technologically complicated and energy-intensive. Boreskov Institute of Catalysis together with AO “Gazpromneft-MNPZ” developed the catalyst and a single stage hydrotreating process of GCC. Developed catalyst provides selective hydrotreating of all GCC fractions without prefractionation to obtain gasoline with a sulfur content of no more than 10 ppm, and octane number loss not more than 1 point.