A Numerical Study of the Effects of Operating Conditions and Coal Properties on Cavity Growth in Underground Coal Gasification

2006 ◽  
Vol 20 (2) ◽  
pp. 596-608 ◽  
Author(s):  
Greg Perkins ◽  
Veena Sahajwalla
Keyword(s):  
Coal Gasification ◽  
Numerical Study ◽  
Cavity Growth ◽  
Operating Conditions ◽  
Underground Coal Gasification ◽  
Coal Properties

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.

Laboratory studies on combustion cavity growth in lignite coal blocks in the context of underground coal gasification

Energy ◽  
2010 ◽  
Vol 35 (6) ◽  
pp. 2374-2386 ◽  
Author(s):  
Sateesh Daggupati ◽  
Ramesh N. Mandapati ◽  
Sanjay M. Mahajani ◽  
Anuradda Ganesh ◽  
D.K. Mathur ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Cavity Growth ◽  
Laboratory Studies ◽  
Underground Coal Gasification ◽  
Lignite Coal

scholarly journals Regression Models Utilization to the Underground Temperature Determination at Coal Energy Conversion

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5444
Author(s):  
Milan Durdán ◽  
Marta Benková ◽  
Marek Laciak ◽  
Ján Kačur ◽  
Patrik Flegner
Keyword(s):  
Coal Seam ◽  
Regression Model ◽  
Regression Models ◽  
Coal Gasification ◽  
Cavity Growth ◽  
Temperature Data ◽  
Ex Situ ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Cavity Growth Rate

The underground coal gasification represents a technology capable of obtaining synthetic coal gas from hard-reached coal deposits and coal beds with tectonic faults. This technology is also less expensive than conventional coal mining. The cavity is formed in the coal seam by converting coal to synthetic gas during the underground coal gasification process. The cavity growth rate and the gasification queue’s moving velocity are affected by controllable variables, i.e., the operation pressure, the gasification agent, and the laboratory coal seam geometry. These variables can be continuously measured by standard measuring devices and techniques as opposed to the underground temperature. This paper researches the possibility of the regression models utilization for temperature data prediction for this reason. Several regression models were proposed that were differed in their structures, i.e., the number and type of selected controllable variables as independent variables. The goal was to find such a regression model structure, where the underground temperature is predicted with the greatest possible accuracy. The regression model structures’ proposal was realized on data obtained from two laboratory measurements realized in the ex situ reactor. The obtained temperature data can be used for visualization of the cavity growth in the gasified coal seam.

A Side Wall Burn Model for Cavity Growth in Underground Coal Gasification

1983 ◽  
Vol 105 (2) ◽  
pp. 145-155 ◽  
Author(s):  
T. L. Eddy ◽  
S. H. Schwartz
Keyword(s):  
Coal Gasification ◽  
Cavity Growth ◽  
Side Wall ◽  
Field Tests ◽  
Underground Coal Gasification ◽  
Convection Diffusion ◽  
Bituminous Coals ◽  
Thin Seam ◽  
Burn Through ◽  
Cavity Width

A mechanistic computer model is presented which predicts the 3-D cavity growth during the gasification phase of underground coal gasification. Developed for swelling bituminous coals, the model also obtains reasonable cavity width and length values for shrinking sub-bituminous coals. The model predicts cavity shape and burn-through times based on the coal properties, seam thickness, water reacting and the interwell distance. Employing a 2-D boundary layer model to determine the convective diffusion rate of oxygen to the reacting walls, it is found that natural convection diffusion must be included. The model includes flow in the injection region, the swirling, mixing effect in the cavity, and transitions from thick to thin seam geometry. Simulations of the Hanna II, Phase 2 and Pricetown I field tests, as well as a parametric study on Pittsburgh seam coal, are presented.

Prediction and parametric analysis of cavity growth for the underground coal gasification project Thar

Energy ◽  
2019 ◽  
Vol 172 ◽  
pp. 1277-1290 ◽  
Author(s):  
Syed Bilal Javed ◽  
Ali Arshad Uppal ◽  
Aamer Iqbal Bhatti ◽  
Raza Samar
Keyword(s):  
Parametric Analysis ◽  
Coal Gasification ◽  
Cavity Growth ◽  
Underground Coal Gasification
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