Effect of Ruthenium and Cerium Oxide (IV) Promotors on the Removal of Carbon Deposit Formed during the Mixed Methane Reforming Process

This work investigates the effect of the addition of Ru and CeO2 on the process of gasification of carbon deposits formed on the surface of a nickel catalyst during the mixed methane reforming process. Activity studies of the mixed methane reforming process were carried out on (Ru)-Ni/CeO2-Al2O3 catalysts at the temperature of 650–750 °C. The ruthenium-promoted catalyst exhibited the highest activity. Carbonized post-reaction catalyst samples were tested with the TOC technique to investigate the carbonization state of the samples. The bimetallic catalyst had the lowest amount of carbon deposit (1.5%) after reaction at 750 °C. The reactivity of the carbon species was assessed in mixtures of oxygen, hydrogen, carbon dioxide, and water. Regardless of the gasifying agent used, the carbon deposit was removed from the surface of the catalytic system. The overall mechanism of mixed methane reforming over Ru and CeO2 was shown.

In situ H-ZSM-5 Zeolite Deactivation Study in Dimethyl Ether to Hydrocarbons Transformation Reaction

Today, catalytic processes for the synthetic fuel components production are of considerable interest for both scientific and industrial area. The transformation of dimethyl ether into hydrocarbons is one of the possible solutions for the development of a closed hydrocarbon cycle, in connection with which a wide study of this process is an important task of modern catalysis. The transformation of dimethyl ether into hydrocarbons occurs with the formation of heavy polyaromatic hydrocarbons, which are deposited on the surface of active centers, which in turn prevents the further occurrence of chemical processes on their surface. This article presents a study of the deactivation of zeolite H-ZSM-5 by the thermogravimetric method in situ. The results of experiments carried out in the temperature range from to 300 to 400 °C are presented. The accumulation of carbon deposits in the first hour of operation indicates the presence of an induction period due to the formation of the first layer of carbon deposits. Linear decontamination occurs when the first five weight percent of carbon deposits accumulate. Further accumulation of carbon deposits up to eight weight percent leads to a sharp decrease in the rate of conversion of dimethyl ether into hydrocarbons to 0.08 kg (DME) / (kg (Cat) h). In the first hour of operation, aromatic hydrocarbons predominate in the reaction medium; with increasing time, the concentration of aromatic hydrocarbons decreases, and the concentration of light olefins and alkanes increases due to carbonization of the catalyst surface. The concentration of heavy aromatic hydrocarbons with a number of carbon atoms equal to or greater than eleven has a maximum after 240 minutes of reaction. The decrease in the content of heavy aromatic hydrocarbons after 240 minutes of reaction can be explained by the sharp loss of surface acidity due to carbonation.

Investigation into Biomass Tar-Based Carbon Deposits as Reduction Agents on Iron Ore Using the Tar Impregnation Method

Increasing carbon deposits in iron ore to upgrade the reduction rate can be performed by impregnating iron ore in tar. Carbon containing iron ore was prepared from low-grade iron ore and biomass tar, which was generated from palm kernel shell (PKS) pyrolysis using the impregnation method. The optimum condition of the method was investigated by varying the tar-iron ore ratio (1 and 1.5) and impregnation time (0 and 24 h). After the carbonization of the tar–iron ore mixture in a flow-type quartz tubular fixed-bed reactor at 500 °C for an hour, the carbon deposits adhered well to surfaces of all iron ore samples. The carbon deposits increased when the ratio of tar-iron ore was enhanced. The effect of impregnation time on the formed carbon deposit only applied to the tar-iron ore ratio of 1, but it had a weak effect on the ratio of 1.5. The highest carbon content was obtained from the impregnation of a biomass tar–iron ore mixture with the ratio of 1.5 which was directly carbonized. In addition, the high water content of biomass tar affected the reformation of FeOOH at the impregnation within 24 h. Furthermore, the reduction reactivity of the obtained carbonized ore, which was observed using thermogravimetric analysis, was perceptible. The carbon deposits on iron ore were able to demote total weight loss up to 23%, compared to 8% of the dehydrated ore, during the heating process to 950 °C. The carbon content obtained from iron ore impregnation with biomass tar can act as reduction agents, thereby enhancing the reduction reactivity.

Influence of cavitation on the working surfaces of the cylinder&piston group of a diesel engine during maintenance

It is established, that the destruction of carbon deposits when the engine is running on a water-fuel emulsion occurs due to the phenomenon of micro-impact of emulsified fuel droplets, the evaporation rate of which depends on their diameter, pressure and amplitude of the gaseous medium. As a result of the removal of carbon deposits in the engines, there is an increase in the average compression value for the engine cylinders by 8 % and the engine power by 11 %, as well as a decrease in the specific fuel consumption by 10 % and the smoke of the exhaust gases by 16 %. Keywords: engine, water-fuel emulsion, micro-impact, emulsified fuel, compression. [email protected]

POTENTIAL OF CARBON STORAGE IN ANGSANA PLANT (Pterocarpus indicus Willd) IN ILIR BARAT I DISTRICT, PALEMBANG CITY

This aims of the study is to determine the potential for carbon deposits and uptake in Angsana (Pterocarpus indicus Willd) tree species. This research was carried out in December 2019. To determine the potential for carbon storage, the Allometric Equation formula was used to estimate biomass stored in it. A half of the biomass is carbon content stored. The results of this study showed that the largest estimation of carbon storage in green space of Ilir Barat I District at the point of observation of GOR / PSCC with a total carbon content of 17,999 tons / ha with an individual number of 23 species of Angsana plants (Pterocarpus indicus Willd). For the District of Ilir Barat I in the City of Palembang, it is expected to increase the number of Angsana (Pterocarpus indicus Willd) plants because these plants can absorb enough carbon and have strong roots

Transformations of ethane and ethylene with methane on a resistive fechral catalyst in the presence of hydrogen

Transformations of methane-ethane, methane-ethylene, hydrogen-ethane and hydrogen-ethylene mixtures on an electrically heated resistive fechral catalyst were studied. During the transformations, the catalyst surface becomes covered with graphitic carbon deposits, which exertan additional catalytic action leading to the formation of C3 and C4 hydrocarbons. The formation of the indicated hydrocarbons proceeds most likely with the involvement of ethylene produced from ethane. The presence of hydrogen suppresses coking of the catalyst surface and decreases the yields of C3 and C4 hydrocarbons.

Removing carbon deposits from parts of the combustion chamber of diesel engines

The Leader4M apparatus for removing carbon deposition with the help of hydrogenair mixture in internal combustion engines was developed. The efficiency of this apparatus when cleaning the engine parts from carbonand coke deposition was proved. Power indicators of diesel engines of BMW X1 2.0 td and Land Rover Discovery 3.0 td were measured before and after cleaning the combustion chamber parts of these engines using the Leader4M installation. After cleaning the parts of these engines from carbon deposits using the Leader4M unit, the maximum power of the engines increased by 2.0–2.1 %, and the maximum torque of these engines increased by 0.2–1.8 %. Keywords internal combustion engines; diesel engine; diesel fuel; carbon formation; hydrogenair mixture

Selected Aspects of Hydrogen Production via Catalytic Decomposition of Hydrocarbons

Owing to the high hydrogen content, hydrocarbons are considered as an alternative source for hydrogen energy purposes. Complete decomposition of hydrocarbons results in the formation of gaseous hydrogen and solid carbonaceous by-product. The process is complicated by the methane formation reaction when the released hydrogen interacts with the formed carbon deposits. The present study is focused on the effects of the reaction mixture composition. Variations in the inlet hydrogen and methane concentrations were found to influence the carbon product’s morphology and the hydrogen production efficiency. The catalyst containing NiO (82 wt%), CuO (13 wt%), and Al2O3 (5 wt%) was prepared via a mechanochemical activating procedure. Kinetics of the catalytic process of hydrocarbons decomposition was studied using a reactor equipped with McBain balances. The effects of the process parameters were explored in a tubular quartz reactor with chromatographic analysis of the outlet gaseous products. In the latter case, the catalyst was loaded piecemeal. The texture and morphology of the produced carbon deposits were investigated by nitrogen adsorption and electron microscopy techniques.