Changes in properties of tar obtained during underground coal gasification process

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.

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Changes in Properties of Tar Obtained During Underground Coal Gasification Process

10.21203/rs.3.rs-130979/v1 ◽

2020 ◽

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

Abstract In 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.

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An ex Situ Underground Coal Gasification Experiment with a Siderite Interlayer. Course of the Process, Production Gas, Temperatures and Energy Efficiency

10.21203/rs.3.rs-127348/v1 ◽

2020 ◽

Author(s):

Marian Wiatowski ◽

Krzysztof Kapusta ◽

Jacek Nowak ◽

Marcin Szyja ◽

Wioleta Basa

Keyword(s):

Energy Efficiency ◽

High Temperature ◽

Flow Rate ◽

Coal Gasification ◽

High Energy ◽

Ex Situ ◽

Hard Coal ◽

Underground Coal Gasification ◽

Gasification Process ◽

Process Gas

Abstract A 72-hour ex situ hard coal gasification test in one large block of coal was carried out. The gasifying agent was oxygen with a constant flow rate of 4.5 Nm3/h. The surroundings of coal were simulated with wet sand with 11% moisture content. A 2-cm interlayer of siderite was placed in the horizontal cut of the coal block. As a result of this process, gas with an average flow rate of 12.46 Nm3/h was produced. No direct influence of siderite on the gasification process was observed; however, measurements of CO2 content in the siderite interlayer before and after the process allowed to determine the location of high-temperature zones in the reactor. The greatest influence on the efficiency of the gasification process was exerted by water contained in wet sand. At the high temperature that prevailed in the reactor, this water evaporated and reacted with the incandescent coal, producing hydrogen and carbon monoxide. This reaction contributed to the relatively high calorific value of the resulting process gas, averaging 9.41 MJ/kmol, and to the high energy efficiency of the whole gasification process, which amounted to approximately 70%.

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Modelling of Underground Coal Gasification Process Using CFD Methods / Modelowanie Procesu Podziemnego Zgazowania Węgla Kamiennego Z Zastosowaniem Metod CFD

Archives of Mining Sciences ◽

10.1515/amsc-2015-0043 ◽

2015 ◽

Vol 60 (3) ◽

pp. 663-676 ◽

Cited By ~ 1

Author(s):

Jan Wachowicz ◽

Jacek Marian Łączny ◽

Sebastian Iwaszenko ◽

Tomasz Janoszek ◽

Magdalena Cempa-Balewicz

Keyword(s):

Chemical Reactions ◽

Coal Gasification ◽

Time Interval ◽

Underground Coal Gasification ◽

Grid Data ◽

Ansys Fluent ◽

Model Studies ◽

Gasification Process ◽

Process Gas ◽

In Situ Conditions

Abstract The results of model studies involving numerical simulation of underground coal gasification process are presented. For the purpose of the study, the software of computational fluid dynamics (CFD) was selected for simulation of underground coal gasification. Based on the review of the literature, it was decided that ANSYS-Fluent will be used as software for the performance of model studies. The ANSYS- -Fluent software was used for numerical calculations in order to identify the distribution of changes in the concentration of syngas components as a function of duration of coal gasification process. The nature of the calculations was predictive. A geometric model has been developed based on construction data of the georeactor used during the researches in Experimental Mine “Barbara” and Coal Mine “Wieczorek” and it was prepared by generating a numerical grid. Data concerning the georeactor power supply method and the parameters maintained during the process used to define the numerical model. Some part of data was supplemented based on the literature sources. The main assumption was to base the simulation of the georeactor operation on a mathematical models describing reactive fluid flow. Components of the process gas and the gasification agent move along the gasification channel and simulate physicochemical phenomena associated with the transfer of mass and energy as well as chemical reactions (together with the energy effect). Chemical reactions of the gasification process are based on a kinetic equation which determines the course of a particular type of equation of chemical coal gasification. The interaction of gas with the surrounding coal layer has also been described as a part of the model. The description concerned the transport of thermal energy. The coal seam and the mass rock are treated as a homogeneous body. Modelling studies assumed the coal gasification process is carried out with the participation of separately oxygen and air as a gasification agent, under the specific conditions of the georeactor operations within the time interval of 100 hours and 305 hours. The results of the numerical solution have been compared with the results of experimental results under in-situ conditions.

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An exsitu underground coal gasification experiment with a siderite interlayer: course of the process, production gas, temperatures and energy efficiency

International Journal of Coal Science & Technology ◽

10.1007/s40789-021-00456-y ◽

2021 ◽

Author(s):

Marian Wiatowski ◽

Krzysztof Kapusta ◽

Jacek Nowak ◽

Marcin Szyja ◽

Wioleta Basa

Keyword(s):

Energy Efficiency ◽

High Temperature ◽

Flow Rate ◽

Coal Gasification ◽

High Energy ◽

Ex Situ ◽

Hard Coal ◽

Underground Coal Gasification ◽

Gasification Process ◽

Process Gas

AbstractA 72-h ex situ hard coal gasification test in one large block of coal was carried out. The gasifying agent was oxygen with a constant flow rate of 4.5 m3/h. The surroundings of coal were simulated with wet sand with 11% moisture content. A 2-cm interlayer of siderite was placed in the horizontal cut of the coal block. As a result of this process, gas with an average flow rate of 12.46 m3/h was produced. No direct influence of siderite on the gasification process was observed; however, measurements of CO2 content in the siderite interlayer before and after the process allow to determine the location of high-temperature zones in the reactor. The greatest influence on the efficiency of the gasification process was exerted by water contained in wet sand. At the high temperature that prevailed in the reactor, this water evaporated and reacted with the incandescent coal, producing hydrogen and carbon monoxide. This reaction contributes to the relatively high calorific value of the resulting process gas, averaging 9.41 MJ/kmol, and to the high energy efficiency of the whole gasification process, which amounts to approximately 70%.

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

Fuel ◽

10.1016/0016-2361(90)90149-k ◽

1990 ◽

Vol 69 (5) ◽

pp. 624-632 ◽

Cited By ~ 33

Author(s):

A DUFAUX ◽

B GAVEAU ◽

R LETOLLE ◽

M MOSTADE ◽

M NOEL ◽

...

Keyword(s):

Coal Gasification ◽

Underground Coal Gasification ◽

Gasification Process ◽

Isotopic Measurements

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

Energies ◽

10.3390/en14206533 ◽

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.

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Characteristics of "Three Zones" during Underground Coal Gasification

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.524-527.56 ◽

2012 ◽

Vol 524-527 ◽

pp. 56-62 ◽

Cited By ~ 2

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.

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The Design, Selection, and Application of Oil-Free Screw Compressors for Fuel Gas Service

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2812784 ◽

1995 ◽

Vol 117 (1) ◽

pp. 74-80 ◽

Cited By ~ 1

Author(s):

K. D. Lelgemann

Keyword(s):

Gas Flow ◽

Coal Gasification ◽

Landfill Gas ◽

Coke Oven ◽

Lubricating Oil ◽

Screw Compressor ◽

Fuel Gas ◽

Process Gas ◽

Design Selection ◽

Shaft Seals

Fuel gas compressors installed in cogeneration systems must be highly reliable and efficient machines. The screw compressor can usually be designed to meet most of the gas flow rates and pressure conditions generally required for such installations. To an ever-increasing degree, alternative sources are being found for the fuel gas supply, such as coke-oven gas, blast-furnace gas, flare gas, landfill gas, and synthesis gas from coal gasification or from pyrolysis. A feature of the oil-free screw compressor when such gases are being considered is the isolation of the gas compression space from the bearing and gear lubrication system by using positive shaft seals. This ensures that the process gas cannot be contaminated by the lubricating oil, and that there is no risk of loss of lubricant viscosity by gas solution in the oil. This feature enables the compressed gas to contain relatively high levels of particulate contamination without danger of “sludge” formation, and also permits the injection of water or liquid solvents into the compression space, to reduce the temperature rise due to the heat of compression, or to “wash” any particulate matter through the compressor.

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

ASME 2006 Power Conference ◽

10.1115/power2006-88064 ◽

2006 ◽

Cited By ~ 1

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.

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