Chemistry of the Gasification of Carbonaceous Raw Material

2021 ◽  
Vol 1045 ◽  
pp. 67-78
Author(s):  
Pavlo Saik ◽  
Roman Dychkovskyi ◽  
Vasyl Lozynskyi ◽  
Volodymyr Falshtynskyi ◽  
Edgar Caseres Cabana ◽  
...  

The paper represents the studies of the process of carbonaceous raw material gasification. The initial material is represented by bituminous coal of grade H with the carbon (C) content of 79.2-85.3 %. Experimental studies have been used to substantiate the parameters of combustible generator gases (СО, Н2, СН4) output depending on the temperature of a reduction zone of the reaction channel and gas flow velocity along its length. It has been identified that the volume of the raw material input to be used for gasification process changes in direct proportion depending on the amount of burnt-out carbon and blow velocity. The gasification is intensified in terms of equal concentration of oxygen and carbon in the reaction channel of an underground gas generator. The gasification rate is stipulated by the intensity of chemical reactions, which depend immediately on the modes of blow mixture supply. Moreover, they depend directly on the intensity of oxygen supply to the coal mass and removal of the gasification products.

2019 ◽  
Vol 968 ◽  
pp. 35-43
Author(s):  
Varvara Vinichenko ◽  
Anton Riazanov ◽  
Aleksandr Riazanov

Pure calcium carbonate, chalk, and coal wastes are taken as starting materials. The Gibbs energy of calcium carbonate decarbonization reactions is calculated. By the method of thermodynamic analysis, the effect of carbon and its gasification products on the calcium carbonate decarbonization process is investigated. The intensifying effect of organic matter during heat treatment of calcium carbonate is shown. In addition to carbon, the decarbonization reactions are influenced by gases evolved as a result of the gasification of the organic part of the coal waste. It is theoretically proven that the organic component of coal waste contributes to lowering the temperature of the onset and end of the decomposition of calcium carbonate. To confirm the theoretical background, experimental studies of the behavior of mixtures during heating have been carried out. The effect of organic matter on decarbonization of pure calcium carbonate and chalk has been studied. Thermograms have shown that less caloric energy is required for the decarbonization of chalk than for the decarbonization of pure CaCO3. Organic transformations occur in the material layer, which contributes to intensive heat transfer. The products of thermochemical transformations of the organic mass increase the efficiency of the process of decarbonization of calcium carbonate using the waste of coal enrichment in the composition of the raw mix. The organic component of the waste not only reduces the amount of heat energy expended on the endothermic process of calcination, its presence in the raw material mix reduces the temperature of the process of calcination as pure calcium carbonate and chalk.


2019 ◽  
Vol 112 ◽  
pp. 02007 ◽  
Author(s):  
Radostin Dimitrov ◽  
Zdravko Ivanov ◽  
Penka Zlateva ◽  
Veselin Mihaylov

The article is focused on the potential and application of biogas, as an alternative fuel from Renewable Energy Sources, for use mainly in gas-generator stations. Biogas fuel is basically a mixture of methane and carbon dioxide. Its composition depends on the type of raw material used for its production. Methane concentration in biogas is between 50÷80%. To be possible engine to work with maximum efficiency with different biogas fuels, it is necessary to modify specific adjustment parameters depending on the concentration of methane in the mixture. This requires the creation of a biogas simulation system for different concentrations of the main components. The aim is to investigate and determine the optimum and permissible biofuel blend concentrations and their impact on engine performance and fuel consumption. Biogas can be used as a fuel to produce electricity, heat or steam or as fuel for internal combustion engine, and its use will help to reduce harmful emissions into the atmosphere.


Author(s):  
E. M. Kashin ◽  
V. N. Didenko

The article presents a new method for determining the composition of wood generator gas produced in gas generators of the inverted gasification process. The shortcomings of the existing calculation methods are analyzed, the main of which is the insufficient harmonization of the calculation results with the experimental data. The authors substantiate the priority of the main chemical reactions occurring during gasification of wood fuel. There are three active zones of gasification, viz.: a redox zone, a reduction zone and a zone of interaction of gasification products with each other and with the carbon of the fuel. In general, a redox zone consists of two subzones: in the first one reactions of water gas formation occur, and the second one appears when excess air is supplied to the gas generator. The proposed method for calculating the components of the generator gas is a set of a modified balance method and an added method for calculating the concentrations of chemical reaction products by the equilibrium constants of these reactions in the active gasification zones with different temperatures. The modified balance method considers the primary processes of wood and moist air transformation into components of the generator gas in the first subzone of the redox zone. The modified balance method is based on the equations of material balance of carbon, hydrogen, oxygen, moisture, nitrogen and thermal balance of the system. The added method determines the concentrations of the components of the generator gas in the second subzone of the redox zone, as well as in the reduction zone and the zone of interaction of the gasification products with each other and with the fuel carbon. The combination of these two methods makes it possible to calculate with greater accuracy the output of the generator gas, the concentration of its components, fuel and air consumption, as well as a number of other characteristics of the gas generator.


2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.


2021 ◽  
Vol 67 (2) ◽  
pp. 216-221
Author(s):  
A. D. Mansfeld ◽  
G. P. Volkov ◽  
R. V. Belyaev ◽  
A. G. Sanin ◽  
P. R. Gromov ◽  
...  

2021 ◽  
Vol 1022 ◽  
pp. 80-86
Author(s):  
Mikhail G. Kholodnyak ◽  
Sergey A. Stelmakh ◽  
Evgeniy M. Shcherban ◽  
Mukhuma P. Nazhuev

The paper considers the current state of the mineral raw material base and the construction material market of the Rostov Region. The effect of various factors on the strain-stress behavior of local limestones has been investigated. The scientific and technical literary sources devoted to the processes of rock failure under various loads have been analyzed. The experimental studies have shown that the tested samples of limestone with a high content of cuboidal grains have characteristics comparable to those of the crushed granite stone. It has been concluded that the use of the Rostov Region limestones in the construction industry is competitive and feasible, provided the proper implementation of the engineering measures proposed in their production.


Author(s):  
Arup Kumar Biswas ◽  
Wasu Suksuwan ◽  
Khamphe Phoungthong ◽  
Makatar Wae-hayee

Underground Coal Gasification (UCG) is thought to be the most favourable clean coal technology option from geological-engineering-environmental viewpoint (less polluting and high efficiency) for extracting energy from coal without digging it out or burning it on the surface. UCG process requires only injecting oxidizing agent (O2 or air with steam) as raw material, into the buried coal seam, at an effective ratio which regulates the performance of gasification. This study aims to evaluate the influence of equivalent ratio (ER) on the flow and combustion characteristics in a typical half tear-drop shape of UCG cavity which is generally formed during the UCG process. A flow modeling software, Ansys FLUENT is used to construct a 3-D model and to solve problems in the cavity. The boundary conditions are- (i) a mass-flow-inlet passing oxidizer (in this case, air) into the cavity, (ii) a fuel-inlet where the coal volatiles are originated and (iii) a pressure-outlet for flowing the product Syngas out of the cavity. A steady-state simulation has been run using k-? turbulence model. The mass flow rate of air varied according to an equivalent ratio (ER) of 0.16, 0.33, 0.49 and 0.82, while the fuel flow rate was fixed. The optimal condition of ER has been identified through observing flow and combustion characteristics, which looked apparently stable at ER 0.33. In general, the flow circulation mainly takes place around the ash-rubble pile. A high temperature zone is found at the air-releasing point of the injection pipe into the ash-rubble pile. This study could practically be useful to identify one of the vital controlling factors of gasification performance (i.e., ER impact on product gas flow characteristics) which might become a cost-effective solution in advance of commencement of any physical operation.


Author(s):  
І. О. Іванов ◽  
Н. П. Супрун ◽  
Ю. О. Ващенко

Investigation of the influence of the peculiarities of raw material composition and structure of traditional and innovative linen textile materials on their hygienic properties. Theoretical and experimental investigations are based on the main positions of textile materials science. In experimental studies, modern standardized methods for determining the hygienic properties of textile materials were used, as well as techniques specially developed taking into account the peculiarities of the operating conditions of underwear. The peculiarities of the operating conditions and the basic functions of hospital underwear were determined. The comparative analysis of hygienic properties of traditional and modern fabrics for underwear was carried out. Using the standardized and the developed methods, adapted to the peculiarities of the conditions of use of the products, the indicators characterizing the processes of water absorption of the materials were experimentally determined. On the basis of the obtained values of quality indicators, a comprehensive assessment of the ability of materials to transfer moisture and air, with the calculation of the arithmetic complex quality index was done. This allowed to determine the material that is optimal in properties, which provides thermophysiological comfort when operating hospital underwear. Using the developed methods, which take into account the specifics of the operating conditions, a comparative analysis of the hygienic properties of traditional and innovative materials for underwear was carried out. A new range of textile materials for underwear has been proposed, taking into account the peculiarities of the operational situation of consumption.


Author(s):  
Tatyana A. Brusentseva ◽  
◽  
Vladislav S. Shikalov ◽  
Sergei M. Lavruk ◽  
Vasily M. Fomin

The work is devoted to the deposition of composite powder materials by cold spray method. As a spraying material, a thermoplastic compound «WAY» for marking the roadway was used. An asphalt concrete was used as a substrate. As a result of experimental studies, the dependence of the deposition efficiency on the stagnation temperature of the working air in the ejector nozzle was obtained. The ANSYS Fluent package was used for evaluative modeling of the cold spraying process. Gas flow patterns were obtained in the computational domain without particles and taking into account the interaction of the flow with particles. The trajectory of the particles was calculated for various spraying parameters


2018 ◽  
Vol 7 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Maryudi Maryudi ◽  
Agus Aktawan ◽  
Siti Salamah

National energy demand has been fulfilled by non-renewable energy sources, such as natural gas, petroleum, coal and so on. However, non-renewable energy reserves deplete increasingly which can cause an energy crisis. Conversion of biomass into energy becomes one of the solutions to overcome it. Indonesia has an enormous biomass potential especially from sugarcane plantation. Sugarcane plantations produce waste of bagasse abundantly. Commonly bagasse is utilized as energy source by conventional combustion.  This research studies the utilization of bagasse as energy source by gasification technology to produce gas fuel. The gasification model used in this research is downdraft gasifier equipped with cyclone to separate gas with solid or liquid gasification products. The result has shown  that gasification of bagasse has produced flammable syngas. The increase of bagasse weight increases the amount of syngas of gasification process. Carbon monoxide is the greatest content of syngas, while a few amount of H2, CH4 are also detected. Bagasse through gasification process is very potential source of alternative energy, since it is derived from waste and a cheap material.


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