S. V. Lysenko

Mesoporous aluminosilicates as components of gas oil cracking and higher-alkane hydroisomerization catalysts

Mesoporous aluminosilicates with a Si/Al ratio of 5 to 20, a pore diameter of 30 to 84 Å, and a specific surface area up to 1030 cm3/g have been prepared using hexadecylamine and Pluronic P123 as templates. These materials exhibit high activity in the cracking of hydrotreated vacuum gas oil. Bifunctional catalysts derived on their basis have high selectivity in the hydroisomerization of hexadecane.

Hydrogenation of aromatic compounds in the presence of dibenzothiophene over bimetallic catalysts containing mesoporous aluminosilicates

The hydrogenation of a mixture of naphthalene, tetralin, and toluene (a solution in n-heptane) in the presence of dibenzothiophene (150 and 400 ppm on a sulfur basis) over Pt-Pd catalysts containing Al-HMS mesoporous aluminosilicates has been studied. The catalyst supports contained 35 wt % Al-HMS and 65 wt % γ-Al2O3. The Pt and Pd loadings in the catalysts were 0.2 and 0.8 wt %, respectively. The process was carried out at 200–240°C, a pressure of 30 atm, and a weight hourly space velocity of 1.7 h−1. It has been found that the catalyst based on Al-HMS with Si/Al = 10 exhibits the highest activity. Thus, in the hydrogenation of a model mixture containing 150 and 400 ppm of sulfur, the conversion of toluene at 240°C was 22.2 and 10.9 wt %, respectively. In the presence of this catalyst, the concentration of aromatic hydrocarbons in the hydrotreated diesel fraction decreased from 28.4 to 6.8 wt %, and the sulfur content decreased from 45 to 5 ppm.

Hydrogenation of aromatic hydrocarbons over nickel–tungsten sulfide catalysts containing mesoporous aluminosilicates of different nature

The hydrogenation of naphthalene, toluene, and 2-methylnaphthalene used as model compounds; the hydrodearomatization of the methylnaphthalene fraction; and the hydrocracking of oil sludge over Ni–W sulfide catalysts supported on BEA/TUD, BEA/SBA-15, and ZSM-5/SBA-15 composites containing SBA-15 and TUD mesoporous silicates have been studied. Catalytic tests have been conducted in an autoclave at 300–400°C and an initial hydrogen pressure of 50–90 atm. It has been found that the highest activity is exhibited by the catalyst based on the ZSM-5/SBA-15 (1) composite prepared by the double-templating synthesis and characterized by a specific surface area of 400 m2/g and an acidity of 409 μmol/g. Thus, in the case of dearomatization of the methylnaphthalene fraction at 300°C and an H2 pressure of 50 atm, the content of diaromatic compounds has decreased from 99.0 to 53.4%, while the amount of sulfur compounds has decreased almost 15-fold. The hydrocracking of oil sludge over NiW/ZSM-5/SBA-15 (2) at 400°C and an H2 pressure of 90 atm has led to an increase in the content of light fractions to 52%.

Conversion of C19–C38 n-paraffins into components of kerosene and diesel fuels on Pt-containing amorphous aluminosilicate

The behavior of Pt-containing catalysts based on mesoporous amorphous aluminosilicate in the process of hydroconversion of C19–C38n-paraffins with the goal to produce diesel and kerosene fractions with improved cold flow properties was investigated. These systems were characterized by high efficiency and selectivity in the process of producing diesel and kerosene fractions. A 91% degree of conversion was achieved with a yield of liquid hydrocarbons of 76% (320°C, volume feed rate 0.5 h–1, molar ratio hydrogen: feed = 600: 1, pressure 50 atm). The initial freezing point of the isolated kerosene fraction was below minus 50°C, and the cold filter plugging point of the diesel fraction was minus 34°C.

Catalytic Cracking of Petroleum Feedstock in the Presence of Additives Derived from Cross–Linked Mesoporous Oxides for Reduction of the Sulfur Content in Liquid Products

Sulfurreducing La/MCM–41/γ–Al2O3 additives to a commercial zeolitecontaining cracking catalyst derived from MCM–41/γ–Al2O3 support with different ratios of the MCM–41 and γ–Al2O3 components were evaluated. Vacuum gas oil cracking at 500°C in the presence of these additives (10 wt. % additive in the catalyst) reduces sulfur in the liquid products by 20–31%.

Hydroisomerization of n-dodecane on bifunctional catalysts containing mesoporous aluminosilicates

The hydroisomerization of n-dodecane on bifunctional catalysts with mesostructured aluminosilicates as an active component has been studied. Aluminosilicates with an Si/Al atomic ratio of 5 to 48 have been prepared using hexadecylamine as a template. Catalyst supports contained 35 wt % mesoporous material and 65 wt % γ-Al2O3. The platinum loading of the catalysts was 0.5% of the support mass. It has been found that the catalysts based on mesoporous aluminosilicates with an Si/Al ratio of 10 and 22 exhibit the highest selectivity. In their presence, the conversion reaches 43–46 wt % with the selectivity for iso-C12H26 of more than 90%.

Hydroconversion of rosin acids in the presence of Pt-containing Al–HMS mesoporous aluminosilicate

The hydroconversion of a mixture of rosin acids over a Pt-containing mesoporous aluminosilicate catalyst has been studied. It has been shown that in a temperature range of 300–350°C at pressures of 30–50 atm and a feedstock/catalyst weight ratio of 20/1, rosin acids undergo complete decarboxylation to form naphthenic and naphthene-aromatic hydrocarbons. Under optimum process conditions, the yield of diesel fuel hydrocarbons is more than 85%. The resulting fraction can be used as a fuel component.

Properties of mesoporous aluminosilicates prepared with nonionic surfactants

Mesoporous aluminosilicates with specific surface area up to 1030 m2/g and pore diameters from 33 to 43 Å were obtained using hexadecylamine and block copolymers of polyethylene and polypropylene oxides as structural directing agents. The synthesized materials were tested in catalytic cracking of hydrotreated vacuum gas oil at 500°C.

Study of processes of deactivation of cracking catalysts by heavy metals and the mechanism of their passivation: 2. XPES study of the state of nickel and antimony and their distribution in cracking catalysts

Conclusions1.The degree of reduction of nickel on RSG-6Ts cracking catalyst is significantly lower than on SiO2, and the dispersion of the metal on RSG-6Ts is significantly higher, due to the reaction of nickel with the aluminosilicate matrix.2.The antimony is more uniformly distributed on the surface than the nickel, forming a monomolecular layer or small islets of Sb2O5. No reduction of antimony was detected on brief treatment in H2 at 550°C.3.The increase in the “metal stability” of the catalysts in the presence of antimony is due to a decrease in the dispersion of Ni0 and perhaps by modification if its properties caused by the presence of a monolayer of antimony oxide on the Ni/SiO2-Al2O3 interface.

Bimetallic Sulfur-Reducing Additives Based on Al–MCM-41 Structured Aluminosilicate for Cracking Catalysts

An ordered mesoporous aluminosilicate of the Al–MCM-41 type has been studied as a component of additives for of petroleum feedstock cracking catalysts. The influence of the nature of the modifying material and its concentration on the activity of the additive has been investigated. It has been shown that the use of bimetallic additives on the basis of ordered mesoporous aluminosilicate makes it possible to reduce the sulfur content in liquid cracking products of vacuum gas oil by 37% more effectively in comparison with that for an additive-free industrial catalyst.