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.

Underground Coal Gasification Research

1983 ◽  
Vol 105 (2) ◽  
pp. 165-169 ◽  
Author(s):  
G. J. Harloff
Keyword(s):  
Mathematical Modeling ◽  
Coal Gasification ◽  
Cavity Growth ◽  
Field Tests ◽  
Resource Recovery ◽  
Laboratory Research ◽  
Gas Composition ◽  
Underground Coal Gasification ◽  
Complex Processes ◽  
Research Studies

Recent successful field tests of underground coal gasification, UCG, have demonstrated the potential for UCG commercialization. This paper presents results of mathematical modeling and laboratory research studies which have been conducted to improve our understanding of the complex processes involved. These studies include: cavity growth including resource recovery, gas composition, and subsidence. Both single and multi-module results are presented.

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 Evaluation of Energy Recovery from Laboratory Experiments and Small-scale Field Tests of Underground Coal Gasification (UCG)

2015 ◽  
Vol 131 (5) ◽  
pp. 203-218 ◽  
Author(s):  
Faqiang SU ◽  
Ken-ichi ITAKURA ◽  
Gota DEGUCHI ◽  
Koutarou OHGA ◽  
Mamoru KAIHO
Keyword(s):  
Energy Recovery ◽  
Laboratory Experiments ◽  
Coal Gasification ◽  
Field Tests ◽  
Small Scale ◽  
Underground Coal Gasification ◽  
Scale Field

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.

The Effect of Moisture on the Structural Stability of a Coal Cavity

1986 ◽  
Vol 108 (3) ◽  
pp. 246-253 ◽  
Author(s):  
H. R. Mortazavi ◽  
A. F. Emery ◽  
R. C. Corlett ◽  
W. R. Lockwood
Keyword(s):  
Coal Gasification ◽  
Failure Modes ◽  
Crack Formation ◽  
Western United States ◽  
Internal Cavity ◽  
Underground Coal Gasification ◽  
Structural Failure ◽  
Convection Diffusion ◽  
Cavity Collapse ◽  
Internal Convection

The drying of coal and the associated thermal and moisture-induced stresses are examined with a numerical model to estimate the rate of surface regression in underground coal gasification. The model includes internal convection, diffusion, conduction and flow of liquid, vapor and gas. The structural failure is modeled by three different mechanisms based upon a strength reduction due to heating, drying, or crack formation. Using properties and boundary conditions appropriate to Western United States coal, the model predicts a regression rate which is in qualitative agreement with measured results. Using the model, it is possible to examine different thermal and failure modes and to gain an understanding of some of the mechanisms which may control the surface regression of coal during gasification. These results may be applicable to the formation of rubble during gasification and to internal cavity collapse.

scholarly journals A Review of Underground Coal Gasification Field Tests Sponsored by the U.S. Department of Energy

2017 ◽  
Author(s):  
E Shafirovich ◽  
E B Jones ◽  
M Machado ◽  
J Mena ◽  
D Rodriguez ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Field Tests ◽  
Department Of Energy ◽  
Underground Coal Gasification ◽  
The U.S
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