The present work shows that the introduction of 0.25-1.25 wt% lanthanum to the composition of aluminum hydroxide at the stage of its hydrothermal synthesis allows increasing the content of the pseudoboehmite phase in the product up to 95 wt% and, as a consequence, reduces the content of the "amorphous" component. Lanthanum uniformly distributes over the surface of aluminum hydroxide as isolated cations with a surface density of 10-15 cations per 10 nm(2). During plasticizing of lanthanum-modified pseudoboehmite followed by granulation and heat treatment, the formation of the oxide form of La is not observed, and the cations retain their isolated state. The specific surface area of La-modified alumina increases by 18-26 m(2)/g compared to the unmodified sample, while the pore volume remains the same and the average pore diameter slightly reduces. It was found that when the content of La in pseudoboehmite was 1 wt%, the temperature of reaching a residual sulfur content of 10 ppm in the hydrotreated diesel fuel was 5 degrees C lower comparing to the unmodified sample.

The effect of Si incorporation at the stage of alumina preparation on physico-chemical properties and catalytic performance of NiMo/Al2O3 catalysts for FCC feedstock pretreatment has been studied. Silicon was added to alumina support by kneading. Si/Al molar ratio was 0-0.16. Supports and catalysts were characterized by XRD, MAS NMR spectroscopy, Raman and IR spectroscopies, nitrogen adsorption-desorption, HRTEM, UV-Vis DRS, XPS. Introduction of Si changes textural characteristics of supports and leads to the decrease in acidity of parent alumina caused by blocking of a part of surface OH groups by deposits of silicon compounds. Silicon addition promotes the formation of small amount of strong LAS and strong BAS. Incorporation of Si facilitates segregation of Ni from the NiMoS phase. Testing of catalysts in VGO hydrotreating shows that addition of silicon to alumina support by kneading improves hydrodesulfurization activity of catalysts. However, an improvement in HDN activity was not achieved.

A process for the preparation active aluminum hydroxyoxide using flash calcination (no longer than 3 s) of gibbsite in a new energy-effective centrifugal drum-type reactor TSEFLAR is considered. The influence of the process parameters on properties of the target product is determined. The temperature and residence time of the particles on the rotating drum surface is established to produce the active aluminum hydroxyoxide of the composition Al2O3·(3-z)H2O (where z = 2.5–2.8) with high chemical activity (solubility in the sodium hydroxide solution) and the specific surface area larger than 200 m2/g is characteristic of the product. Models of particle motion along the reactor surface and of their heat states are suggested to establish the process parameters determining the product properties, such as the residence time of the particles on the surface, particle temperature, and residual water content. The energy consumption for the gibbsite activation in the drum-type reactor is as low as one third of that of the currently used industrial technology based on thermal treatment of gibbsite in flowing flue gases.

The influence of the order of catalysts and their ratio in the bed for FCC feedstock hydrotreatment was investigated. CoMo/Al2O3 and NiMo/Al2O3 catalysts were prepared in the laboratory and studied by nitrogen adsorption-desorption, XPS and HRTEM methods. The catalysts were tested in hydrotreatment of model feedstocks. It was found that NiMo/Al2O3 catalyst had the highest activity in conversion of the model feedstock containing sulfur and nitrogen compounds. The best results were obtained for the feedstock firstly treated by NiMo/Al2O3 and then by CoMo/Al2O3. Catalysts were tested separately and together in hydrotreatment of SRVGO. The order of catalysts and their ratio were varied. The best combination included NiMo/Al2O3 catalyst at the top of the reactor and CoMo/Al2O3 at the bottom of the reactor in the ratio of 40/60 vol%.

В настоящее время постоянно ужесточаются экологические и химмотологические требования к дизельным топливам.Производство топлив, удовлетворяющих нормам Евро-5 и Евро-6 возможно только при использовании катализаторов гидроочистки последнего поколения.В России при разработке импортозамещающих катализаторов в условиях исследовательских институтов, для контроля химических, текстурных, структурномеханических и каталитических свойств, научным сотрудникам доступны самые разнообразные информативные методы анализа.Когда процесс оптимизации катализатора завершен, встает вопрос о наработке опытно-промышленных партий на промышленном оборудовании.Разовая загрузка типичного реактора гидроочистки низкого давления составляет не менее 30 тонн катализатора.Т.е.необходимо масштабировать процесс синтеза от лабораторного (десятки граммов) до промышленного (десятки тонн) уровня.Синтез катализатора гидроочистки -сложный процесс, состоящий из нескольких последовательных стадий.На первой из термоактивированного гидроксида алюминия получают псевдобемит с заданными текстурными характеристиками.Далее псевдобемит пептизируют и путем грануляции образовавшейся пасты получают носитель необходимой формы с заданными параметрами влагоемкости и прочности на раздавливание.Носитель пропитывают многокомпонентным раствором, содержащим металлы в определенных комплексных соединениях, а полученный катализатор сушат.Для получения качественного катализатора на каждой стадии необходимо контролировать до 10 различных характеристик полупродуктов.Таким образом, синтез опытно-промышленной партии катализатора -это серьезная задача не только с точки зрения соблюдения условий синтеза, но и объемная работа для аналитического контроля качества процесса приготовления катализатора.Особенно это актуально ввиду того, что на действующих российских катализаторных производствах нет готовой аналитической базы для характеризации катализаторов гидроочистки последнего поколения.Так, например, для контроля содержания нанесенных активных компонентов катализатора, в исследовательских лабораториях, зачастую используют многоэлементный информативный метод ИСП-АЭС, который практически не присутствует в парке аналитического оборудования большинства катализаторных предприятий.Проблемой встает отсутствие методик анализа основного компонента на всех стадиях синтеза катализатора: анализ сырья, анализ пропиточных растворов, анализ сливных вод, анализ катализатора.Для сопоставления результатов анализа ряда текстурных и структурно-механических методов, присутствующих на заводе, но по характеристикам отличных от используемых в исследовательском институте, необходимо получить матрицы результатов анализа образцов с различным значением характеристик и получить корреляции для оценки результатов, получаемых при наработке на производстве.В рамках аналитического сопровождения наработки опытно-промышленной партии катализатора гидроочистки дизельного топлива,

Influence of Si addition at the stage of boehmite preparation on properties of NiMo/Al2O3 catalysts for FCC feedstock pretreatment have been studied. The series of boehmites doped by PDMS at the stage of hydrothermal treatment was prepared. Si/Al molar ratio was 0, 0.01, 0.015 and 0.02. Boehmites were used for supports and catalysts preparation. Boehmites, supports and catalysts have been characterized by XRD, TGA, nitrogen adsorption-desorption, IR spectroscopy, UV-Vis, Si-29 MAS NMR, HRTEM, EDX, XPS. Catalysts were tested in hydrotreating of FCC feedstock. It is shown that there are changes in morphology of boehmite particles and textural characteristics of aluminas. Introduction of Si to alumina induces formation of wider mesopores and blocks part of the Lewis acid sites of alumina. Testing of catalysts in hydrotreating of FCC feedstock shows that the catalyst with Si/Al ratio of 0.01 in boehmite has the best combination of hydrodesulfurization and hydrodenitrogenation activities.

The influence of alumina precursors on catalytic activity CoMoP/Al2O3 hydrotreating catalysts has been studied. Alumina precursors were prepared by eco-friendly technology including hydrothermal treatment at different stabilization time of a flash calcined gibbsite. One sample was synthesized with the addition of boric acid. A reference sample of pseudoboehmite was obtained by precipitation from aluminum nitrate with aqueous ammonia. Alumina precursors, supports and catalysts were studied by XRD, nitrogen adsorption/desorption, XPS, HRTEM. CoMoP/Al2O3 catalysts were tested in hydrotreating of model feed and fuel mixture. It is shown that the samples obtained from the product of flash calcination of gibbsite, besides pseudoboehmite, also include the amorphous phase, while the reference sample, synthesized by precipitation, is a pure pseudoboehmite. The introduction of boron prevents the crystallization of pseudoboehmite. Textural properties of the catalysts depend of initial support: alumina samples prepared by hydrothermal treatment have a bimodal pore distribution with peaks at 60-70 angstrom and 150-200 angstrom, the support synthesized through reprecipitation has a unimodal distribution with a maximum at 80 angstrom. The initial alumina used as a catalyst support has a significant impact on the share of CoMoS phase of type II. The highest activities in the hydrotreating of model feed (dibenzothiophene, quinoline and naphthalene in undecane) and fuel mixture shown catalyst prepared using hydrothermal treatment of flash calcined gibbsite without addition boric acid and with short stabilization time.

The influence of alumina precursors on NiMo/gamma-Al2O3 catalysts for silicon removal from gas oil have been studied. Alumina precursors were prepared by hydrothermal treatment of gibbsite, precipitation of aluminum nitrate by ammonia and precipitation of aluminum nitrate in autoclave. Alumina precursors, supports and catalysts were studied by XRD, nitrogen adsorption-desorption, IR spectroscopy, UV-vis, XPS, SEM, HRTEM. Series of NiMo/gamma-Al2O3 catalysts differed in preparation method of alumina precursors was tested in hydrotreating of diesel fraction contaminated with decamethylcyclopentasiloxane as a model silicon compound. It was shown that prepared alumina precursors were boehmites and dawsonite, which had different particle size. The supports prepared from these alumina precursors were gamma-Al2O3 with different particles size. It was shown that there was a dependence of the surface area of the support on the size of primary particles measured by XRD. The higher surface area results in the higher content of OH groups and silicon sorption capacity. Morphology of the sulfide active component also depends on the size of primary particles. The higher length of the particles, the higher slab length of NiMoS phase. The catalyst with the lowest particle size of alumina and highest length of active component had the highest HDS activity.

The problem of optimizing the textural characteristics and chemical composition of the alumina support of a vacuum gasoil hydrotreating catalyst is considered. The catalyst is synthesized using the state-of-the-art environmentally friendly technology of flash calcination of gibbsite. Ways of increasing its specific surface area by introducing inorganic additives containing boron or sulfur at the stage of synthesizing boehmite with needle-shaped particles are developed. It is established that introducing such modifiers raises S BET by 50–100 m 2 /g, relative to the maximum values that can be attained by varying the standard parameters of hydrothermal treatment. It is shown that introducing boron at the stage of boehmite synthesis improves the catalytic activity of CoNiMoP catalyst in the hydrodesulfurization and hydrodenitrogenation of vacuum gasoil by two or more times, relative to a similar catalyst doped with boron from an impregnating solution.

Under discussion is optimization of texture and chemical composition of alumina as the support for the catalyst for hydrotreatment of vacuum gasoil synthesized using the environmentally friendly modern technology of flash thermal treatment of gibbsite. Approaches to increasing the specific surface area by introducing inorganic admixtures (including boron or sulfur) at the stage of synthesis of pseudoboehmite were developed. The introduction of these modifiers was established to increase SBET by 50–100 m2/g comparing to the maximal areas attaineddue to variation in the standard process parameters of the hydrothermal treatment. It was shown that the introduction of boron at the stage of pseudoboehmite synthesis resulted in no less than two times increase in the catalytic activity of CoNiMoP to hydrodesulfurization and hydrodenitrogenation against the activity of a similar catalyst with boron introduced with the impregnating solution.

New results of endothermic dehydration of undiluted ethanol on alumina catalyst in pilot wall-heated tubular reactor are presented. Activity and physicochemical characteristics of the proprietary acid-modified alumina (AMA) prepared by gibbsite flash calcination in TSEFLAR (TM) reactor were compared to the properties of commercially available alumina samples prepared by precipitation (CS1) or flash calcination of gibbsite in a flue gas (CS2). The samples differed in phase composition, which corresponds to gamma-Al2O3 in CS1, mixed gamma- and chi-Al2O3 in AMA and CS2; sodium content and concentration of Lewis acid sites (LAS) were different as well. Acid modification resulted in AMA catalyst with improved acidic properties and catalytic activity higher than that of CS2, despite the lower sodium content in the latter. Ethanol-to-ethylene dehydration in the wall-heated tubular reactor proceeded at the catalyst bed temperatures mainly below 385 degrees C, where AMA catalyst is the most active due to the highest content of strong LAS. The heat-agent temperature favors yield of ethylene rather than that of by-products. Higher linear velocity and porosity contribute to a flatter axial temperature profile in the bed; a higher average integral temperature gives a quantitative estimate. This ensures higher ethylene yield with a lower ethanol consumption even at a reduced heat-agent temperature. On the ring-shaped AMA catalyst, the greater ethylene yield, catalyst productivity and sharply reduced hydraulic resistance are reached compared to CS2 cylinders. For the first time we showed that use of AMA ring-shaped catalyst in wall-heated tubular reactor in contrast to the SynDol alumina based catalyst in adiabatic reactor can improve the catalyst productivity by 5-8 times and WHSV by 5-12 times.

The influence of textural characteristics of NiMo/Al2O3 on silicon capacity and hydrotreating activity has been investigated so as to develop guard-bed catalyst for silicon removal from middle distillates. Series of NiMo/Al2O3 catalysts with a specific surface area from 150 to 210 m(2)/g and an average pore diameter from 21.1 to 10.5 nm have been synthesized. The difference in textural characteristics has been achieved by variation of aging time and temperature of hydrothermal treatment of boehmites. The boehmites, supports and catalysts were studied by various physico-chemical methods: XRD, nitrogen adsorption-desorption, IR spectroscopy, UV-vis, H-1 NMR, Al-27 NMR, XPS, SEM, HRTEM. Catalysts were tested in hydrotreating of diesel fuel contaminated with decamethylcyclopentasiloxane as a model silicon compound. It is shown that the increase in aging time and temperature of hydrothermal treatment of initial boehmites results in the decrease of OH groups concentration per 1 g of an alumina support. The increase of the OH groups content leads to higher silicon capacity, while HDS activity of catalysts decreases. The study of catalysts surface after reaction showed that Si located on a support surface and did not cover directly active component particles. However, its location on the support near edges of active component particles could result in the decrease of HDS activity due to limited accessibility of the active sites.

Novel eco-friendly method for preparation of mesoporous alumina from the product of rapid thermal treatment of gibbsite (CTA product) without "reprecipitation" stage is described. Compared with the nitrate-ammonia technology of "reprecipitation" of gibbsite to boehmite and its further calcination to gamma-Al2O3, the new method consumed less amount of HNO3 per 1 kg of Al2O3 (by 30 times), while the amount of effluents is twice lower. Effluents do not contain ammonium nitrate, since the preparation of boehmite does not include ammonia. It is shown that the method makes it possible to obtain boehmite with needle-shaped particle morphology. The particle size of boehmite and the textural characteristics of alumina are easily adjusted over a wide range by changing the temperature, aging time or peptizing agent. Thus, the pore volume of alumina may be 0.45-0.95 cm(3)/g with an average pore diameter of 81-256 angstrom and S-BET = 140-240 m(2)/g.

NiMo/γ-Al2O3 protective-layer catalysts for removing silicon from diesel fractions were examined. The catalysts differ in the way in which boron is introduced into the support. The supports and catalysts were examined by X-ray diffraction analysis, transmission electron microscopy, IR spectroscopy, and adsorption–desorption of nitrogen. The catalysts were tested in hydropurification of the diesel fraction to which decamethylcyclopentanesiloxane was added as a model silicon compound. It was shown that introduction of boron into the support results in that the surface area of the supports and catalysts increases. If boron is introduced into pseudoboehmite, massive particles of the Ni–Mo–S phase are formed. It was found that the highest capacity for silicon is observed for the catalyst into which boron is introduced in the stage of pseudoboehmite preparation.

The influence of impregnation of aluminum oxide desiccants prepared by centrifugal thermal activation of hydrargillite with alkali (KОН and NaOH) and carbonate (Na2CO3 and K2СО3) solutions on the physicochemical properties of the products was studied. Impregnation with alkali solutions increases the dynamic capacity of the desiccants by a factor of 2 and more, whereas impregnation with carbonate solutions decreases the sorption characteristics of the desiccants at similar texture characteristics. Introduction of alkaline modifiers leads to a considerable decrease in the concentration of Lewis acid sites on the surface and to an increase in the concentration of strong base sites. Linear correlation was revealed between the concentration of strong base sites on the surface of the desiccants and their dynamic capacity in drying of humid air. The desiccants modified by impregnation exhibit not only high static and dynamic capacity, allowing improvement of the drying efficiency, but also considerably enhanced mechanical strength.

Alumina desiccants obtained by extrusion molding of plastic pastes based on pseudoboehmite or bayerite-containing hydroxides including those modified by sodium and potassium ions were studied. The hydroxides were synthesized by hydration of the product of centrifugal thermal activation of gibbsite under mild conditions. The physicochemical and structural-mechanical properties of the desiccants (fresh and after nine adsorption–regeneration cycles) were studied. The dynamic capacity was determined at a pressure of 3MPa under conditions designed to model the industrial conditions. The sample obtained from bayeritecontaining hydroxide had a higher dynamic capacity than the sample obtained from pseudoboehmite-containing hydroxide at close texture and strength characteristics of adsorbents. Modification of the samples obtained from pseudoboehmite-containing hydroxide with potassium and sodium ions leads to decreased granule stability and increased volume, average pore size, and dynamic capacity. The potassium-modified sample of the desiccant had dynamic capacity as high as that of the sample obtained from bayerite-containing hydroxide at low load. After the cyclic tests, the phase composition, alkaline impurity contents, specific surface area, and crushing strength of the samples did not change within the error of determination. It was found that the prepared desiccants were highly stable in many adsorption–desorption cycles and the minimum dew point of –80°C could be reached during the drying.

Moulding compositions for extrusive granulation were synthesized based on a mixture of aluminum hydroxides prepared by hydration of thermo activated products of hydrargillite – flush and CTA (centrifugal thermal activated) – in electrolyte solutions (NaOH, H2O, HNO3). The molding compositions were obtained by peptization of the hydroxides with nitric acid free of surfactants. Structural and mechanical properties of the compositions such as elasticity (λ), plasticity (Ps), relaxation period (Θ), etc. were determined using an instrument with a plane-parallel gap, the principle of its operation being based on measuring the time tangential shift. The plastic strength (Pm) and optimal moisture content (ϕ) was measured using the penetrometric method by immersing the working body (cone) into the composition under study. The 1 or 2 structuralmechanical type with predominant propagation of slow elastic deformations was shown to be characteristic of the compositions under study. Ranges of elasticity (λ = 0,39÷0,42), plasticity (Ps = (2÷5,6)·10–6 s–1) and relaxation period (Θ =1700÷3350) were determined. The plastic strength (Pm) and optimal masses moisture (φ) were determined to depend on the preparation conditions of the hydroxides and to range as follows: ϕ = 25,98÷30,83 wt.% and Pm = 11,71÷71,44·104 Pa.

Activated alumina desiccants modified with NaOH and KOH were synthesized from the product of a centrifugal thermal activation of gibbsite, with the subsequent hydration in an acid or alkaline medium, and their properties were studied. It was shown that the modification makes it possible to raise the dynamic capacity of desiccants produced from pseudoboehmite by up to a factor of 2 via formation of new super-strong basic centers the concentration of which grows with increasing content of an alkaline oxide. A correlation was found between the total concentration of basic centers on the surface of the desiccants and their dynamic capacity in drying of both dry and humid air. Use of the modified desiccants with high static and dynamic capacity will make it possible to improve the drying efficiency.

Main stages of development of a pilot centrifugal drum-type reactor for manufacturing an X-ray amorphous product (50 kg/h) of hydrargillite activation are reported. Characteristics features of the product are a high reactivity and the specific surface area as large as two orders of magnitude of the initial area. The new reactor is shown to consume as low energy as a half of that consumed by the industrial thermal activation of hydrargillite in flowing flue gases. A mathematical model is suggested for the process of centrifugal thermal activation of hydrargillite to consider the evolution of the heat state of a particle in the course of its heating, dehydration, and cooling. The model allows the energy consumption to be estimated at all the process stages; it will be useful for developing standard series of the reactors.