A Review of Underground Coal Gasification Research and Development in the United States

Camp, David W.

doi:10.2172/1368032

Cited by 10 publications

(5 citation statements)

References 12 publications

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“…The interaction between the UCG and its environment is shown in Figure 4. Field tests in some countries which demonstrated repeatedly shows that the risk of groundwater contamination is real of UCG problem beside subsidence and roof collapse (Camp, 2018). By monitoring and controlling the air in the vulnerable area, the real danger of explosion and poisoning could be evaluated by the simulation model, so it is possible to reduce this risk (Kostúr, Laciak and Durdan, 2018).…”

Section: Potential Hazards At Proposed Ucg Pilot Projectmentioning

confidence: 99%

Study on environmental quality and hazard identification of underground coal gasification project: A literature study and field survey

Damayanti¹

2018

IMJ

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Underground coal gasification (UCG) is a procedure to extract synthesis gas (syngas) from the in situ underground coal seams that could not be extracted by conventional mining methods. This is a clean technology as an alternative method for direct in situ coal conversion. This process involves some heavy equipment and complex operation. Hazards identification and risk assessment in the UCG Project involve identifying the environmental hazards that cover physical, chemical and biological environments to predict the process sequences, its frequency as well as consequences that lead to those hazards. The assignment of risk level is also conducted to design corrective action in minimizing the risk or eliminating the hazards. The environmental condition of the project plan is generally good with the fulfillment of the established environmental quality standards.

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Section: Potential Hazards At Proposed Ucg Pilot Projectmentioning

confidence: 99%

Study on environmental quality and hazard identification of underground coal gasification project: A literature study and field survey

Damayanti¹

2018

IMJ

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“…The underground coal gasification (UCG) process leads to permanent structural changes in the coal seam and the surrounding rock mass, resulting in the creation of a combustion zone with a combustion cavity and a fracture zone [1][2][3][4][5][6][7]. Knowing the size and shape of the cavity is fundamental to UCG technology in terms of the efficiency of the method, as well as its safety for the environment.…”

Section: Introductionmentioning

confidence: 99%

Assessment of Combustion Cavern Geometry in Underground Coal Gasification Process with the Use of Borehole Ground-Penetrating Radar

Pilecki,

Hildebrandt,

Krawiec

et al. 2023

Energies

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In this study, the shape and size of a combustion cavity with a fracture zone in the gasified coal seam was determined with the use of control boreholes and a ground-penetrating radar (BGPR) test. The underground coal gasification (UCG) field-scale experiment was performed in Carboniferous strata in coal seam 501 at a depth of approx. 460 m in the Wieczorek hard coal mine in the Upper Silesian Coal Basin, Poland. After the termination of the UCG reactor, five coring boreholes were drilled to identify the geometry of the resulting combustion cavity and the impact of the UCG process on the surrounding rock mass. Borehole ground-penetrating radar measurements were performed using a 100 MHz antenna in three boreholes with a length of about 40–50 m. This enabled the identification of the boundaries of the combustion cavity and the fracture zone in the coal seam. The fracture zones of rock layers and lithological borders near the control borehole were also depicted. As a result, the cavity was estimated to have a length of around 32 m, a width of around 7 m and a height of around 5 m. The analyses performed with the control boreholes and the BGPR provided sufficient information to determine the geometry of the combustion cavity and the fracture zone.

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“…The effective components of gas gradually decrease with increasing coal consumption volume. When the gas quality stable time does not exceed 15 days, a sharp drop occurs . In the UCG field test in Ulanqab of China, the gas quality and gasification parameters are optimized under certain initial oxygen concentrations and the optimum oxygen concentration is 60–65% .…”

Section: Introductionmentioning

confidence: 99%

“…When the gas quality stable time does not exceed 15 days, a sharp drop occurs. 11 In the UCG field test in Ulanqab of China, the gas quality and gasification parameters are optimized under certain initial oxygen concentrations and the optimum oxygen concentration is 60−65%. 12 Under the appropriate oxygen concentration, the total oxygen injection rate needs to be optimized by experiments.…”

Section: Introductionmentioning

confidence: 99%

Mathematical Modeling of the Underground Coal Gasification Process in One Gasification Cycle

Liu

Chen

et al. 2019

Energy Fuels

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Underground coal gasification (UCG) has its own reaction characteristics with the growth of the combustion cavity because the coal seam is fixed while the gasification face moves. The theoretical understanding of UCG requires continuous and deep research. In order to explain the UCG mechanism by means of simulation calculation, based on the analysis of the reaction process of UCG, radial and axial reaction models are established. The comprehensive heat transfer coefficient of the coal seam is determined by comparing the calculation results with the field test results. The differential method is used to calculate variations in the composition of the outlet gas, the temperature field distribution in the channel, the thickness of the radial reaction zone, and the influence of the oxygen fraction on the length of the oxidation zone. The results indicate that in one gasification cycle, the changes of gas composition is close to that of the field test, which initially increases and then decreases with increasing gasification time. The radial expansion of the coal seam mainly occurs in the high-temperature zone, consistent with the trend of the channel temperature field. The radial expansion thickness in the coal seam is between 0.2 and 0.8 m. The higher the oxygen fraction in the gasifying agent is, the shorter the range of the oxygen distribution along the axial direction will be, that is, the shorter the length of the oxidation zone.

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A Review of Underground Coal Gasification Research and Development in the United States

Cited by 10 publications

References 12 publications

Study on environmental quality and hazard identification of underground coal gasification project: A literature study and field survey

Study on environmental quality and hazard identification of underground coal gasification project: A literature study and field survey

Assessment of Combustion Cavern Geometry in Underground Coal Gasification Process with the Use of Borehole Ground-Penetrating Radar

Mathematical Modeling of the Underground Coal Gasification Process in One Gasification Cycle

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