scholarly journals Analyzing the parameters influencing the efficiency of undereground coal gasification

2018 ◽  
Vol 27 (2) ◽  
pp. 332-336 ◽  
Author(s):  
I. Sadovenko ◽  
O. Inkin ◽  
N. Dereviahina ◽  
Y. Hriplivec
Keyword(s):  
Coal Gasification ◽  
Static Pressure ◽  
Environmental Safety ◽  
Theory And Practice ◽  
Heat Output ◽  
Underground Coal Gasification ◽  
Gas Generator ◽  
Gasification Process ◽  
Negative Effect ◽  
Gas Loss

Relying upon the theory and practice of Podzemgaz stations operation, the paper has analyzed the basic factors working on the efficiency of underground coal gasification;  moreover, it has estimated their function in the formation of gas loss from un- derground gas generator. The determined factors have been divided into initial factors and controllable ones according to their process characteristics and degree of their influ- ence of gasification process itself.The data confirm the dependence of the increased pressure upon the increased heat output. Moreo- ver, high static pressure within gas generator prevents from rock roof caving and reaction channel filling up with molten rock. It has been substantiated that almost all disturbing factors have negative effect on gas calorifity whereas parameters of blast rate increase and static pressure growth in a gas generator have the most positive effect among the controlling factors. Aspects concerning the increase in loss of the produced gas that may reduce economic efficiency and environmental safety of underground coal gasification have been considered as well.

Mathematical and Geomechanical Model in Physical and Chemical Processes of Underground Coal Gasification

2018 ◽  
Vol 277 ◽  
pp. 1-16 ◽  
Author(s):  
Gennadiy Pivnyak ◽  
Roman Dychkovskyi ◽  
Oleksandr Bobyliov ◽  
Edgar Cáceres Cabana ◽  
Adam Smoliński
Keyword(s):  
Coal Gasification ◽  
The Body ◽  
Ministry Of Education ◽  
Underground Coal Gasification ◽  
Gas Generator ◽  
Geomechanical Model ◽  
Waste Products ◽  
Gasification Process ◽  
Geological Conditions ◽  
Scientific Principles

The formation of the stress-strain state of rocks in the several phase gasification processes was considered. Proceeding from the well-known principles of thermodynamics and phase formation of the multi-type rockmass under the influence of the temperature field, a geomechanical model of a two-layer artificially-formed shell formed during the gasification process by the method of variation feeding of the blowing mixture to the body of the gas generator was developed. The Neumann principle is used for the magnitude determination of the maximum stress vector, which involves the definition of the axial tensor of mechanical deformations through the anisotropy of the thermal expansion (the polar tensor of the second rank). This makes the possibility to create the base for a package of information programs creation. Such programs give the possibility to simplify the study of the rockmass deformation characteristics and to evaluate the stresses in a thermally changing environment. Researches are carried out by creating the final element system with the adaptation to the specific mining-geological conditions. These approaches are checked both for working out the coal reserves and for utilization of the mining waste products. Results of this investigation were included to the Roman Dychkovskyi thesis of the scientific degree of the Doctor of the Technique Sciences “Scientific Principles of Technologies Combination for Coal Mining in Weakly Metamorphoses Rockmass”. They contain the researches, which were conducted within the project GP – 489, financed by Ministry of Education and Science of Ukraine.

ACTIVATION OF UNDERGROUND COAL GASIFICATION WITH THE CONSIDERATION OF THE MODE OF THE UNDERGROUND GAS GENERATOR

2020 ◽  
Author(s):  
V Falshtynskyi ◽  
M Lozynska ◽  
D Lozynska
Keyword(s):  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Gas Generator

scholarly journals Changes in properties of tar obtained during underground coal gasification process

2021 ◽  
Author(s):  
Marian Wiatowski ◽  
Roksana Muzyka ◽  
Krzysztof Kapusta ◽  
Maciej Chrubasik
Keyword(s):  
Coal Gasification ◽  
Coal Tar ◽  
Liquid Product ◽  
Coke Oven ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Dominant Component ◽  
Process Gas ◽  
High Volatility ◽  
Product Separator

AbstractIn this study, the composition of tars collected during a six-day underground coal gasification (UCG) test at the experimental mine ‘Barbara’ in Poland in 2013 was examined. During the test, tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven (coal) tar. The obtained results were compared with each other and with the data for coal tar. As gasification progressed, a decreasing trend in the water content and an increasing trend in the ash content were observed. The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline. All tested samples were characterized by very high distillation losses, while for samples starting from the third day of gasification, a clear decrease in losses was visible. A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar. The content of polycyclic aromatic hydrocarbons (PAHs) in UCG tars is several times lower than that in coal tar. No light monoaromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes—BTEX) were found in the analysed tars, which results from the fact that these compounds, due to their high volatility, did not separate from the process gas in the liquid product separator.

Modelling of the underground coal gasification process at Thulin on the basis of thermodynamic equilibria and isotopic measurements

Fuel ◽  
1990 ◽  
Vol 69 (5) ◽  
pp. 624-632 ◽  
Author(s):  
A DUFAUX ◽  
B GAVEAU ◽  
R LETOLLE ◽  
M MOSTADE ◽  
M NOEL ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Isotopic Measurements

scholarly journals Characteristics of Water Contaminants from Underground Coal Gasification (UCG) Process—Effect of Coal Properties and Gasification Pressure

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6533
Author(s):  
Magdalena Pankiewicz-Sperka ◽  
Krzysztof Kapusta ◽  
Wioleta Basa ◽  
Katarzyna Stolecka
Keyword(s):  
Bituminous Coal ◽  
Coal Gasification ◽  
Strong Relationship ◽  
Underground Coal Gasification ◽  
Volatile Phenols ◽  
Water Contaminants ◽  
Physicochemical Composition ◽  
Gasification Process ◽  
Anthracite Coal ◽  
Coal Properties

One of the most important issues during UCG process is wastewater production and treatment. Condensed gasification wastewater is contaminated by many hazardous compounds. The composition of the generated UCG-derived wastewater may vary depending on the type of gasified coal and conditions of the gasification process. The main purpose of this study was a qualitative and quantitative characterization of the UCG wastewater produced during four different UCG experiments. Experiments were conducted using semi-anthracite and bituminous coal samples at two distinct pressures, i.e., 20 and 40 bar. The conducted studies revealed significant relationships between the physicochemical composition of the wastewater and the coal properties as well as the gasification pressure. The strongest impact is noticeable in the case of organic pollutants, especially phenols, BTEX and PAH’s. The most abundant group of pollutants were phenols. Conducted studies showed significantly higher concentration levels for bituminous coal: 29.25–49.5 mg/L whereas for semi-anthracite effluents these concentrations were in much lower range 2.1–29.7 mg/L. The opposite situation occurs for BTEX, higher concentrations were in wastewater from semi-anthracite gasification: 5483.1–1496.7 µg/L, while in samples from bituminous coal gasification average BTEX concentrations were: 2514.3–1354.4 µg/L. A similar relationship occurs for the PAH’s concentrations. The higher values were in case of wastewater from semi-anthracite coal experiments and were in range 362–1658 µg/L while from bituminous coal gasification PAH’s values are in lower ranges 407–1090 µg/L. The studies conducted have shown that concentrations of phenols, BTEX and PAH’s decrease with increasing pressure. Pearson’s correlation analysis was performed to enhance the interpretation of the obtained experimental data and showed a very strong relationship between three parameters: phenols, volatile phenols and CODcr.

Characteristics of "Three Zones" during Underground Coal Gasification

2012 ◽  
Vol 524-527 ◽  
pp. 56-62 ◽  
Author(s):  
Hong Tao Liu ◽  
Hong Yao ◽  
Kai Yao ◽  
Feng Chen ◽  
Guang Qian Luo
Keyword(s):  
Large Scale ◽  
Coal Gasification ◽  
Basic Knowledge ◽  
Gas Composition ◽  
Underground Coal Gasification ◽  
Reduction Zone ◽  
Gasification Process ◽  
Product Gas ◽  
Dry Distillation ◽  
Major Chemical

According to the temperature, major chemical reactions and gas compositions, the gasification process along the tunnel of underground coal gasification is divided into three zones, i.e. oxidation zone, reduction zone and dry distillation zone. A model test in the laboratory was carried out by using large-scale coal blocks to simulate the coal seam. The characteristics of the “three zones”, and the relation between the temperature and gas composition were also quantitative studied. It provided the necessary basic knowledge for further studying the process of underground coal gasification, including predicting compositions of product gas, life-cycle analyzing, selecting optimistic control parameters and determining suitable gasification craft.

The Exergy Underground Coal Gasification Technology as a Source of Superior Fuel for Power Generation

2006 ◽  
Author(s):  
Michael S. Blinderman
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Fuel Gas ◽  
Gasification Process ◽  
Product Gas ◽  
Production Wells ◽  
Industrial Projects ◽  
Fossil Fuel Power Plants

Underground Coal Gasification (UCG) is a gasification process carried on in non-mined coal seams using injection and production wells drilled from the surface, converting coal in situ into a product gas usable for chemical processes and power generation. The UCG process developed, refined and practiced by Ergo Exergy Technologies is called the Exergy UCG Technology or εUCG® Technology. The εUCG technology is being applied in numerous power generation and chemical projects worldwide. These include power projects in South Africa (1,200 MWe), India (750 MWe), Pakistan, and Canada, as well as chemical projects in Australia and Canada. A number of εUCG based industrial projects are now at a feasibility stage in New Zealand, USA, and Europe. An example of εUCG application is the Chinchilla Project in Australia where the technology demonstrated continuous, consistent production of commercial quantities of quality fuel gas for over 30 months. The project is currently targeting a 24,000 barrel per day synthetic diesel plant based on εUCG syngas supply. The εUCG technology has demonstrated exceptional environmental performance. The εUCG methods and techniques of environmental management are an effective tool to ensure environmental protection during an industrial application. A εUCG-IGCC power plant will generate electricity at a much lower cost than existing or proposed fossil fuel power plants. CO2 emissions of the plant can be reduced to a level 55% less than those of a supercritical coal-fired plant and 25% less than the emissions of NG CC.

Heavy water tracing test in the underground coal gasification process at Thulin

Fuel ◽  
1990 ◽  
Vol 69 (11) ◽  
pp. 1454-1456 ◽  
Author(s):  
Anne Dufaux ◽  
Bénédicte Gaveau ◽  
René Létolle ◽  
Marc Mostade ◽  
Marianne Noël ◽  
...  
Keyword(s):  
Heavy Water ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Tracing Test ◽  
Water Tracing

scholarly journals Determination of the Extent of the Rock Destruction Zones around a Gasification Channel on the Basis of Strength Tests of Sandstone and Claystone Samples Heated at High Temperatures up to 1200 °C and Exposed to Water

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6464
Author(s):  
Krzysztof Skrzypkowski ◽  
Krzysztof Zagórski ◽  
Anna Zagórska
Keyword(s):  
Numerical Simulations ◽  
High Temperatures ◽  
Laboratory Tests ◽  
Coal Gasification ◽  
Structural Parameters ◽  
Underground Coal Gasification ◽  
Rock Destruction ◽  
Gasification Process ◽  
Destruction Zone ◽  
Gasification Channel

This article presents the results of laboratory tests regarding the influence of high temperatures on changes in the strength and structural parameters of rocks that are present in the immediate vicinity of a gasification channel. Sandstone and claystone samples were heated at 300 °C, 600 °C, 900 °C and 1200 °C. Additionally, the heated samples were placed in water for 24 h. The results of the laboratory tests were used in the numerical simulation using RS2 software. The main goal of modeling was to determine the extent of the rock destruction zone around the gasification channel for dry and wet rock masses. In the numerical simulations, three widths of the gasification channel and three ranges of high-temperature impact were modeled. On the basis of the obtained results, it was found that the extent of rock destruction, both in the roof and in the floor, is greater by several percent for a wet rock mass. For the first time, this research presents the effect of water on heated rock samples in terms of the underground coal gasification process. The results of laboratory tests and numerical simulations clearly indicate a reduction in strength, deformation and structural parameters for the temperature of 1200 °C.

scholarly journals Effect of Lignite Properties on Its Suitability for the Implementation of Underground Coal Gasification (UCG) in Selected Deposits

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5816
Author(s):  
Krzysztof Kapusta
Keyword(s):  
Moisture Content ◽  
Coal Gasification ◽  
Calorific Value ◽  
Process Efficiency ◽  
Average Moisture Content ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Laboratory Setup ◽  
Large Bulk

Two experimental simulations of underground coal gasification (UCG) processes, using large bulk samples of lignites, were conducted in a surface laboratory setup. Two different lignite samples were used for the oxygen-blown experiments, i.e., “Velenje” meta-lignite (Slovenia) and “Oltenia” ortho-lignite (Romania). The average moisture content of the samples was 31.6wt.% and 45.6wt.% for the Velenje and Oltenia samples, respectively. The main aim of the study was to assess the suitability of the tested lignites for the underground coal gasification process. The gas composition and its production rates, as well as the temperatures in the artificial seams, were continuously monitored during the experiments. The average calorific value of gas produced during the Velenje lignite experiment (6.4 MJ/Nm3) was much higher compared to the result obtained for the experiment with Oltenia lignite (4.8 MJ/Nm3). The Velenje lignite test was also characterized by significantly higher energy efficiency, i.e., 44.6%, compared to the gasification of Oltenia lignite (33.4%). The gasification experiments carried out showed that the physicochemical properties of the lignite used considerably affect the in situ gasification process. Research also indicates that UCG can be considered as a viable option for the extraction of lignite deposits; however, lignites with a lower moisture content and higher energy density are preferred, due to their much higher process efficiency.

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