Ethanol is one of the promising sources of hydrogen (synthesis gas), including in various energy applications. The production of synthesis gas from ethanol is possible in various ways, for example, such as steam and steam-air conversion, which are endothermic and thermoneutal reactions, respectively. Control and management of heat and mass transfer during the occurrence of these reactions is an important task, which can be solved through the use of catalysts on heat-conducting metal substrates. This paper presents the results of a study of the physicochemical properties of Pt, Rh, Pd, Ru, Ni, Co-containing structured catalysts deposited on a FeCrAl mesh support, studied in the processes of steam and steam-air conversion of ethanol. Among the tested samples, the ruthenium catalyst showed the greatest efficiency in the processes of steam and steam-air conversion of ethanol, providing an equilibrium composition of the products without visible signs of carbonization.

The article provides a comparative assessment of two design cases of heat input for a compact single-tube steam methane reformer operating at 10 bar and a feed flow rate of 1–3 Nm3/h, filled with a granulated nickel catalyst, and equipped with a 5–15 kW propane–butane burner. In the first design case, the catalyst-filled tube was heated with a flue gas as it was injected from the flame burner (at an excess air ratio of 2.3) through an annular channel that enclosed the tube. In the second design case, the heat was provided by a cylindrical IR burner panel (at an excess air ratio of 1.05) that enclosed the tube. Using mathematical modeling, the performance of both reformer cases was compared, with all other parameters being equal. The IR-burner-based reformer exceeded its flue-gas-heated counterpart in terms of methane conversion, heat recovery efficiency (about twofold for both parameters), the percentage of radiant heat transfer (by a factor of about 2.3), and fuel enthalpy increase (6–7

Ceria-supported copper catalysts exhibit high catalytic performance in the preferential oxidation of CO in excess H2 (CO PROX). Highly dispersed copper oxide species have been experimentally identified as active centers. However, structural diagnostics of highly dispersed CuOx species and CuOx/CeO2 interface areas remains a challenge. Here, we report a comprehensive structural study of a supported CuO/CeO2 catalyst (5 wt

The data obtained for the first time on the influence of the sequence of metal deposition and the conditions of formation of the Re-containing component on the properties of a series of catalysts 1.9 wt % Pt–1.8 wt % Re/Ce 0.75 Zr 0.25 O 2 in the water gas shift reaction are presented. It is shown that catalysts in which platinum is deposited first have a content of both metals close to the expected level and make it possible to achieve the maximum CO conversion at a lower temperature compared to a monometallic platinum catalyst. Based on the data on CO chemisorption and calculations of the reaction rate per platinum surface area, it is assumed that the role of the Re-containing phase is to a greater degree related to the stabilization of a highly dispersed platinum state, rather than to participation in the catalysis of the reaction.

Heterogeneous catalysts xRu/Ce0.75Zr0.25O2 (x = 1, 5 wt.

In the presented work, the process of heat and mass transfer inside an original design nozzle for a catalytic reformer of diesel fuel in a low-mass-flux mode is investigated by direct numerical simulation using Open FOAM open-source code. The main goal of a new nozzle design is to increase the rate and degree of fuel evaporation, as well as to improve the mixing characteristics of diesel fuel with superheated water vapor before the reaction mixture passes through the catalyst. Inside the nozzle, there are two regions where flows with opposite swirl directions are created; this leads to a strong velocity shear inside the nozzle, intensifying the mixing processes. Simulations were carried out in the Eulerian-Lagrangian formulation, taking into account the processes of evaporation of fuel droplets. The simulation results show that the flow at the outlet of the nozzle has a good uniformity of the mixture composition and provides a high degree of fuel evaporation at the early stages of flow development.

A fuel processor for autothermal reforming of diesel fuel into synthesis gas is developed and tested. The developed reactor is demonstrated to possess a fast start-up and high efficiency. During the tests, complete conversion of diesel fuel and the composition of reaction products close to equilibrium values were achieved. The thermal circuit of a power plant based on a solid oxide fuel cell (SOFC) with the electrical power of 1 kW was optimized. The results obtained are the basis for the further development of a real prototype of a power plant based on planar SOFC with an integrated diesel fuel processor, opening up the prospects in the area of making low- power electrochemical generators.

The problems concerning the insufficient level of associated petroleum gas (APG) processing are discussed. Various models are proposed for the chemical utilization of APG, including the production of synthesis gas, methanol, dimethyl ether, ammonia, as well as the processes of aromatization of hydrocarbons, etc. The possibility of using APG as a fuel for generating electricity is discussed. Attention is paid to the processes of APG purification from sulfur impurities. Difficulties and solutions to the problems of the energy sector of APG utilization are discussed.

In this study, supported 5 wt% Ru/Ce0.75Zr0.25O2 catalysts were prepared by sorption-hydrolytic deposition technique, followed by calcination under different conditions, namely in reductive H2/N2 (Ru/CeZr_red) and oxidative air (Ru/CeZr_ox) atmospheres. A thorough characterization of the catalysts was carried out by XRD, CO chemisorption, HRTEM, Raman spectroscopy, XPS, and in situ DRIFTS. The findings showed that the choice of the calcination atmosphere has a great impact on the structural organization of the catalyst. Calcination in air results in the formation of the larger crystalline RuO2 particles, which tend to enlarge upon reduction under CO2 methanation conditions. The reductive treatment results in a much higher dispersion of supported Ru species and a more pronounced metal-support interaction (MSI). In the Ru/CeZr_red catalyst, a large amount of atomic scale Ru species was detected along with metallic Ru nanoparticles and clusters. However, it was found that the superiority of the Ru/CeZr_red catalyst in the Ru dispersion did not result in the significant advantage in the CO2 methanation activity. In situ DRIFTS results suggested that the MSI affects the ability of Ru species to adsorb and activate reagent molecules, in particular, enhances the adsorption strength of the intermediate CO species.

The paper presents the results of a study of Pt and Pd catalysts deposited on porous aluminum oxide in the reaction of hydrogen oxidation reaction for use the process of helium concentrate purification. The properties of the prepared catalysts were compared with the properties of a foreign reference catalyst. In a laboratory reactor using a mixture simulating helium concentrate, we studied the “ignition” and deactivation of catalysts at room temperature, which simulates the conditions at the inlet section of an industrial adiabatic reactor. The properties of catalysts were also studied at temperatures of 200, 250 and 300 °C under conditions simulating the middle part and the outlet of an industrial reactor. The secondary process of hydrogen formation at 250-300 °C was studied, which is explained by methane and ethane steam reforming which present in the model mixture simulating helium concentrate. The results of the work can be used in the development of domestic catalysts for the purification of helium obtained from natural gas.

Pt/Ce1-xZrxO2 catalysts have shown high activity in water gas shift (WGS) reaction, but their structural organization has been studied insufficiently. This work represents a detailed structural study on the supported Pt species and the metal/support interface in a 5 wt% Pt/Ce0.75Zr0.25O2 catalyst in the initial state, after reductive activation, and after WGS reaction in H2-enriched reformate-simulating mixture. A wide range of methods was used: ex situ and in situ X-ray diffraction (XRD) studies, high resolution transmission electron microscopy (HRTEM), X-ray atomic pair distribution function (PDF) method, pseudo in situ X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR). The Ce0.75Zr0.25O2 mixed oxide was shown to provide a highly dispersed state of Pt species. XPS revealed that the initial catalyst contains Pt2+species. PDF analysis allowed us to propose the structure of ultrafine PtO particles and to elucidate the metal-support interaction with fixation of Pt ions on the support surface. In situ XRD, pseudo in situ XPS, and H2-TPR studies revealed the reduction of ultrafine PtO particles in H2 atmosphere at low temperatures (20-90 degrees & Scy;) with the formation of metallic Pt0 particles and simultaneous partial reduction of the support surface due to the hydrogen spillover. Catalytic tests of the as-prepared and poisoned with chlorine 5wt% Pt/Ce0.75Zr0.25O2 catalysts in the WGS reaction showed an important role of the oxygen vacancies in the oxide support as active sites. These findings contribute to the understanding catalytic performance of Pt/Ce1-xZrxO2 systems.

Heteronuclear coordination compounds of d-metals are effective precursors for the production of bimetallic nanoalloys (Plyusnin et al., 2022) [1], which, in turn, are widely used in catalysis. Catalysts based on Rh and Cu, as well as Rh and Zn, are highly active in the process of steam reforming of hydrocarbons. Double oxalates of Rh with Cu and Rh with Zn with the general formula [(C2O4)(H2O)2Rh- (mu-C2O4)-M(H2O)2-(mu-C2O4)-Rh (H2O)2(C2O4)]& sdot;6H2O (M = Cu, Zn) are synthesized and structurally characterized. According to thermogravimetric analysis, the complexes completely decompose in He and H2 atmospheres already at 300 degrees C with the formation of the corresponding nanoalloys in the Cu-Rh and Zn-Rh systems. Calcination in an O2 atmosphere leads to the formation of a mixed oxide with a spinel structure. The Cu-Rh/Ce0.75Zr0.25O2 and Zn-Rh/ Ce0.75Zr0.25O2 catalysts were prepared by impregnation by moisture capacity on a porous support followed by calcination in a hydrogen atmosphere. The obtained catalysts were tested in propane steam reforming for hydrogen production at 300-480 degrees C and WHSV = 10 000-40 000 cm3 h- 1 center dot gcat- 1. At these conditions the Cu-Rh/ Ce0.75Zr0.25O2 and Zn-Rh/Ce0.75Zr0.25O2 catalysts demonstrated high selectivity for hydrogen (more than 70 %) compared to the monometallic catalyst Rh/Ce0.75Zr0.25O2 (less than 60%). Bimetallic catalysts make it possible to increase hydrogen productivity by reducing the reaction rate of methanation of carbon oxides, which is achieved due to the presence of Cu and Zn in the catalyst structure.

The influence of platinum additives on the properties of rhodium catalysts in the processes of steam reforming and autothermal reforming of diesel fuel was investigated. It was found that Rh/CZF was more active compared to the bimetallic sample Rh–Pt/CZF: the degree of fuel conversion in its presence was higher, and the concentration of reaction by-products was lower. The proposed two-zone Pt/CZF + Rh/CZF structured honeycomb catalyst demonstrated stable performance and high activity in the autothermal reforming of commercial diesel fuel. However, the presence of platinum in the frontal zone of the catalyst reduced its resistance to coking compared to the rhodium-containing sample. The results obtained are of practical significance in the development of efficient systems for the conversion of heavy hydrocarbons into synthesis gas.

Методом сорбционно-гидролитического осаждения приготовлены гетерогенные катализаторы состава хRu/Ce0.75Zr0.25O2 (x=1, 5 масс. %). Показано, что катализаторы активны в реакции метанирования диоксида углерода. Проведена комплексная диагностика состава и структурных особенностей катализаторов с использованием методов порошковой рентгеновской дифракции, электронной микроскопии высокого разрешения, хемосорбции, а также рентгеновской фотоэлектронной спектроскопии (РФЭС). Показано, что метод сорбционно-гидролитического осаждения позволяет получать катализаторы с высокодисперсным состоянием активного компонента. Катализатор с 1 масс. % Ru содержит соединения рутения в виде атомарных кластеров, в катализаторе с 5 масс. % наряду с ультрадисперсными формами образуются окристаллизованные рутенийсодержащие частицы. Установлено, что исходные катализаторы содержат оксидные соединения рутения, которые в условиях реакции метанирования претерпевают восстановление до металлического состояния. Результаты in situ диагностики методами порошковой дифракции и РФЭС, а также термопрограммируемого восстановления водородом (H2-ТПВ) показали, что в процессе активационной обработки катализаторов нагревом в обогащённой водородом газовой среде образующиеся кластеры или частицы металлического рутения промотируют процесс частичного восстановления оксидного носителя за счет спилловер эффекта.

The work proposed a macrokinetic model of first-order CO2 sorption on a 10 mol.% NaNO3/MgO sorbent. Based on the analysis of experimental gravimetric data, the maximum sorption capacity of the sorbent 10 mol.% NaNO3/MgO was determined, which does not depend on the partial pressure of CO2 and at 320 °C is 159% (based on the initial mass of the sample), or 13.4 mmol CO2/ gsorb. The calculated value of the sorption constant kads at temperatures of 280-320 °C and a partial pressure of CO2 of 0.50-0.75 atm is 0.017 min-1 atm-1. Based on the obtained kinetics, a simulation of an adiabatic and isothermal CO2 adsorber was made within the framework of a technological scheme for producing hydrogen 10 kg/h from natural gas at an operating pressure of 12 atm. During the calculations, it was shown that for the effective functioning of the adsorber, intensive removal of the heat released during the sorption process is necessary. This allows CO2 sorption to be carried out for 30 minutes at a temperature of 300 °C and a volumetric flow rate GHSV = 1170 h-1, while the concentration of CO2 at the outlet in dry gas does not exceed 1.5 mol.%.

In this work, sorbents based on magnesium oxide MgO modified with NaNO3 taken in a concentration of 5–50 mol

The influence of platinum additives on the properties of rhodium catalysts in steam and autothermal reforming processes of diesel fuel was investigated. It was found that the Rh/CZF catalyst exhibited higher activity, with a higher degree of fuel conversion and lower production of side reaction products compared to the bimetallic Rh–Pt/CZF catalyst. The proposed two-zone catalytic Pt/CZF+Rh/CZF structured honeycomb catalyst demonstrated stable performance and high activity in autothermal reforming of commercial diesel fuel. However, the presence of platinum in the frontal zone of the catalyst reduced its resistance to coking compared to the rhodium-containing sample. The obtained results are of practical significance in the development of efficient systems for the conversion of heavy hydrocarbons into synthesis gas.

The previously proposed stationary mathematical model provides a reliable description of n-hexadecane (diesel surrogate) reforming over the Rh/Ce0·75Zr0·25O2-δ/θ-Al2O3/FeCrAl structured catalyst. In its continuation this work represents the experimental studies and the model of the autothermal reforming process of hexadecane in a mixture with o-xylene and 1-methylnaphthalene. The reaction scheme is supplemented with reactions to account for steam reforming and oxidation of added aromatics compounds and selection of corresponding kinetic parameters is performed. The dynamic process of the reformer start until reaching the steady state is simulated by the non-stationary model in this work. The resulting mathematical and kinetic models provide a good description of the experiments performed with the reproduction of the dynamics of the observed outlet gas components concentrations and the catalyst temperature. The application of this model can be useful when considering the reforming of multicomponent mixtures or optimization of the dynamic start reformer process.

Steam reforming and autothermal reforming of ethanol produce synthesis gas suitable for both powering solid oxide fuel cells and serving as a feedstock for chemical industry applications. For these reactions to occur effectively, heat transfer must be controlled. In the case of endothermic steam reforming of ethanol, the problem of heat transfer from the reactor walls to the catalyst bed arises. For thermoneutral autothermal reforming (steam-air conversion) of ethanol, the problem arises of redistributing the heat released in the front part of the catalyst layer as a result of the oxidation of ethanol with oxygen along the catalyst layer to compensate for the endothermic effect of steam reforming of ethanol. To solve these problems, structured catalysts based on heat-conducting substrates—metal meshes, foam metals, and other supports—are well suited. Such catalysts are a complex composite material with a multi-level structure “structured metal substrate-structural oxide component-active oxide-nanoparticles of metals or alloys”, which combines the functions of a heat exchanger, a flow distributor and the catalyst itself. This work presents the results of the preparation of Pt, Rh, Pd, Ru, Ni, and Co-containing structured catalysts supported on a FeCrAl mesh support and the study of their catalytic properties.

Разработан и испытан топливный процессор для автотермического риформинга дизельного топлива в синтез-газ. Показано, что созданный реактор обладает быстрым запуском и высокой эффективностью. В ходе испытаний была достигнута полная конверсия дизельного топлива и близкий к равновесным значениям состав основных продуктов реакции. Оптимизирована тепловая схема энергоустановки на основе твердооксидного топливного элемента (ТОТЭ) с электрической мощностью 1 кВт. Полученные результаты являются основой для дальнейшего создания реального макета энергоустановки на основе планарного ТОТЭ с интегрированным дизельным топливным процессором, открывая перспективы в области создания маломощных электрохимических генераторов. A fuel processor for autothermal reforming of diesel fuel into synthesis gas is developed and tested. The developed reactor is demonstrated to possess a fast start-up and high efficiency. During the tests, complete conversion of diesel fuel and the composition of reaction products close to equilibrium values were achieved. The thermal circuit of a power plant based on a solid oxide fuel cell (SOFC) with the electrical power of 1 kW was optimized. The results obtained are the basis for the further development of a real prototype of a power plant based on planar SOFC with an integrated diesel fuel processor, opening up the prospects in the area of making low-power electrochemical generators.