A comparative analysis of the life cycle of powertrains based on internal combustion engines powered by diesel fuel and natural gas, on batteries, and on hydrogen fuel cells was made. The inventory information on the stages of the life cycle of powertrains was collected, including production of structural materials and assembling of powertrain components, production of fuel and power, operation, and recycling/disposal after the service life completion. The results of comprehensive estimation of the energy consumption and СО2 emissions in the life cycle are presented. The structure of the electric power production in the Moscow oblast was used for the comprehensive estimation of the parameters. The cost of hydrogen at which the powertrains based on fuel cells become economically competitive was estimated.

Misfires and fuel shutdown have similar features and affect similarly on overheating the three-way catalyst (TWC). In practice, this similarity is an obstacle to determining whether the misfires or fuel shutdown cause failure of the TWC. Meanwhile, it is of great importance to distinguish fuel shutdown as an original reason from others because its consequences may be tremendous for both the environment and safety. The destruction mechanism of the TWC resulting from the shutdown of fuel supply is described in detail. The mechanism is confirmed by the experimental data obtained on a four-cylinder in-line engine tested on motor bench. The burning process is transferred from the cylinders into the TWC during the fuel shutdown event. The entire process is divided into several stages. Initially, the air-fuel mixture in the cylinders changes so that the air/fuel ratio increases, reaching the lean misfire limit and going beyond this limit, which makes the air-fuel mixture non-combustible. The remains of fuel and oxygen unreacted in the cylinders enter the TWC where combustion occurs in a combination of the catalytic mode, flame combustion in the porous medium and free flame. The destruction mechanism of the TWC due to the fuel shutdown is a sequence of rapid changes in combustion modes in the engine and in the TWC. It may seem strange, since the expected consequence should be a decrease in temperature, as the amount of fuel supplied is reduced. Contrary to the expectations, the fuel shutdown leads to an abrupt heating of the TWC and its complete destruction in an extreme case.

Comparative analysis of the fire and explosion safety in using hydrocarbon fuels and hydrogen as automobile fuel is made. For reliable analysis, it is necessary to take into account the set of all the parameters influencing the fire and explosion safety, including the influence of the composition of multicomponent fuels on their characteristics and the influence of external conditions in cases of both normal operation and emergency; study and comparison of separate properties of fuels are insufficient. Complex analysis of the physicochemical properties of fuels shows that, in case of emergency, the consequences of the hydrogen ejection from the fuel system are in most cases less dangerous compared to the ejection of hydrocarbon fuels. The development of detonation combustion as a result of ignition of a hydrogen–air mixture formed in open space is improbable because of high diffusion ability of hydrogen and impossibility of the buildup of the required concentration. The possibility of wide use of hydrogen as an automobile fuel is substantiated.

The possibility of providing an appreciable decrease in carbon monoxide concentrations in products due to the combustion of natural gas-air mixtures in infrared burners by installing a radiation gauze screen with a catalytic Pd-Ce/Al2O3 coating over the matrix is demonstrated. When permeable matrices with radiation gauze screens with and without catalytic coatings are used, the concentration of nitrogen oxides in combustion products was less than 20 ppm within a range of specific combustion powers from 20 to 100 W/cm2. The use of a screen with a catalytic coating provides record low CO concentrations in combustion products at a level of 3–5 ppm within a range of specific combustion powers from 30 to 60 W/cm2. The catalytic coating on the gauze screen that is developed retains its serviceability through multiple cycles of heating to temperatures of 1400 K.

Aluminum hydroxide was crystallized in a sodium aluminate solution as bayerite at room temperature. Primary particles appeared as conical pyramids. They were born on particles of alpha-Al2O3 which had been preformed on a surface of FeCrAl alloy mesh as a result of its annealing. The primary nucleation was discussed using a two-step model that consists of a formation of prenucleation clusters and their transformation into nuclei. The induction period is an inversely proportional function to a square of the substrate surface and depends on its nature. Stirring the solution affected the primary nucleation preventing the formation of the prenucleation clusters. At an early stage, in a supersaturated state, the lateral surface of the primary pyramids grew via filling kink sites and forming the secondary pyramids. The secondary pyramids appeared from the prenucleation clusters. The pyramid base grew by a screw mechanism with an unwinding spiral. When a supersaturate degree of the solution decreased, the lateral surface grew by filling kink sites only, whereas the screw mechanism transformed into a usual modification of the screw mechanism with the shrinking spiral. The change in the growth mechanism transformed the primary cone-shaped particles into the final needle-shape particles.

Samples of a woven mesh of metal wire (fechral) with supported aluminum hydroxide compounds are studied. Aluminum hydroxide is formed in its bayerite modification. Aluminum oxides are produced during calcination: η-Al2O3 at 600°C, and θ-Al2O3 at 900°C. Subsequent modification with silicon, cerium, lanthanum, tungsten, and calcination at the same temperature results in the formation of their oxides. Interaction between alumina and tungsten at 600°C, and alumina and lanthanum at 900°C, are observed.

Addition of Pt/Al2O3 to a ceria-containing oxide allows studying oxygen storage capacity at lower temperatures. The advantage is achieved through separation of functions of oxygen storage/release and CO oxidation.

The modified Bayer process allows coating of a metal mesh surface with a continuous aluminum hydroxide layer in the phase of bayerite. Subsequent calcination turns the aluminum hydroxide layer into a eta-alumina layer. The method provides the uniform thickness of tens of microns for the alumina layer. Layers cracking, clogging of mesh cells are not observed. The alumina layer is formed by needle-shaped particles which coalesce to each other through common facets during crystallization. The alumina layer with high specific surface area is perfectly suitable as a support for various active components. A series of Fe-containing mesh-catalysts was tested in the NOx reduction with NH3. Addition of Ce and W to Fe increases NOx conversion significantly. The FeCeW catalyst provides almost 100% of the NOx conversion at a space velocity of 40,000 h(-1) in the range of 350-500 degrees C with a negligible quantity of N2O. A series of Pt-containing catalysts was tested in the reaction of afterburning of hydrocarbons. Addition of tungsten oxide to the Pt/Al2O3 catalyst decreases T-50 by 60 degrees C. An increase in the number of wire mesh leads to a drop of T-50. The mesh-catalyst provides better light-off performance than the honeycomb catalyst. (C) 2016 Elsevier B.V. All rights reserved.

Pipelines that were well designed for conventional oils may not be able to cope with a transition to heavy oils without some retrofit adaptation, as the increased pressure drop may exceed constraints and force some reduction in throughput. In this paper, ways of enhancing the utilization of existing, capital intensive infrastructure by small, incremental additions are explored. A thermo-hydraulic pipeline model for a buried pipeline is presented. The model is then applied to a case study involving a section of the important, recently built Russia-China ESPO pipeline, for which a gradual shift from the current (design) light oil to heavier oils is considered. A number of thermal retrofit scenarios are proposed and assessed which involve the incremental supply of additional heat at selected points. These scenarios go from pre-heating of the oil at entrance to use of single and multiple intermediate heating stations. The heating duty requirements for each case are calculated. The results show that a careful use of such thermal management techniques can significantly mitigate the reduction in throughput that would otherwise be required, leading to significant economic savings in operations. It is highlighted that the development of adaptable, modular low-cost heating technologies would make this approach significantly advantageous over other alternatives. (C) 2016 Elsevier Ltd. All rights reserved.

•Direct evaporation of diesel fuel due to the heat combustion was realized.•Two-stage distributor provided uniform gas flow distribution through the catalyst.•Multilayer catalytic unit based on heat-resistant metal gauze was designed.•Sulfur in diesel fuel does not exert a negative effect on the reactor performance.•120-h testing of radial-type catalytic reactor was successfully carried out.

Исследованы условия получения ацетилена при пиролизе метана на резистивном нагревателе из вольфрамовой нити. При высоких концентрациях метана образуется большое количество сажи в виде мелких частиц и углеродных нитей. Образование сажи практически отсутствует при разбавлении метана гелием. При содержании метана 10–15% и температуре спирали в диапазоне 1800–2000°С получены 80% конверсии метана и 80% селективности по ацетилену. Время контакта составляет несколько сотых долей секунды. Переход с чистого метана на природный газ в указанном температурном диапазоне не влияет на конверсию метана и селективность. Экспериментально определено, что реакция прекращается при снижении температуры газа ниже 800°С.

Acetylene synthesis conditions in methane pyrolysis on a tungsten wire heating element have been investigated. At high temperatures, methane pyrolysis yields a large amount of carbon black as small particles and carbon filaments. Carbon black practically does not form when methane is diluted with helium. At methane concentrations of 10–15% and coil temperatures of 1800–2000°C, 80% methane conversion and 80% acetylene selectivity have been attained at a contact time of a few hundredths of a second. Changing from pure methane to natural gas in the specified temperature range exerts no effect on the methane conversion and acetylene selectivity. It has been experimentally demonstrated that the reaction ceases on the gas temperature is decreased below 800°C.

In this work, we discuss the problem of the afterburning of methane from the exhaust gases of automobile engines fueled by natural gas. In exhaust neutralizers, the PdO/Al2O3 catalyst, the main drawback of which is the reduction of its activity under the action of steam that always present in exhaust gases, is commonly used. To improve the tolerance to steam, a series of PdO-Me x O y /Al2O3 binary catalysts (Me is Co, Cu, Fe, Ni, Mn, or Sn) was prepared and studied. Comparative tests under conditions modeling the methane afterburning process in automobile neutralizers show that Pd catalysts promoted with nickel, cobalt, and tin oxides are more resistant to the inhibiting action of steam. The high crystallinity of supported PdO and its uniform distribution over the surface of modified Al2O3 are indicated as criteria for the stability of catalysts in the presence of steam. Optimization of the concentration of promotors and the preparation method used for their introduction allows the deactivation of Pd catalysts under the action of steam to be almost completely eliminated.

Correlation between the catalytic activity in oxidation of carbonaceous materials and a change in the phase composition of the La 1− x Cs x VO 4± y and Ce 1− x Pr x O 2− d catalysts was studied. The activity values obtained by iso- and polythermal methods are close.