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.

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.

Laboratory studies on cavity growth and product gas composition in the context of underground coal gasification

Energy ◽  
2011 ◽  
Vol 36 (3) ◽  
pp. 1776-1784 ◽  
Author(s):  
Sateesh Daggupati ◽  
Ramesh N. Mandapati ◽  
Sanjay M. Mahajani ◽  
Anuradda Ganesh ◽  
R.K. Sapru ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Cavity Growth ◽  
Gas Composition ◽  
Laboratory Studies ◽  
Underground Coal Gasification ◽  
Product Gas

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

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.

Mathematical modeling of alternating injection of oxygen and steam in underground coal gasification

2015 ◽  
Vol 150-151 ◽  
pp. 154-165 ◽  
Author(s):  
Ali Akbar Eftekhari ◽  
Karl Heinz Wolf ◽  
Jan Rogut ◽  
Hans Bruining
Keyword(s):  
Mathematical Modeling ◽  
Coal Gasification ◽  
Underground Coal Gasification

Mathematical Modeling of the Stream Method of Underground Coal Gasification

1975 ◽  
Vol 15 (05) ◽  
pp. 425-436 ◽  
Author(s):  
C.F. Magnani ◽  
S.M. Farouq Ali
Keyword(s):  
Mathematical Modeling ◽  
Carbon Dioxide ◽  
Coal Seam ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Hydrocarbon Gases ◽  
Underground Gasification ◽  
Performance Curves ◽  
Synthetic Gas

Abstract This investigation focuses on mathematical modeling of the process of underground gasification of coal by the stream method. A one-dimensional, steady-state model consisting of five coupled differential equations was formulated, and the solution, extracted analytically, was used to develop closed-form expressions for the parameters influencing coal gasification. The model then was used for interpreting field performance curves, predicting the results of The performance curves, predicting the results of The field tests, and ascertaining the over-all process sensitivity to the input variables. The usefulness of the model was shown by establishing the parameters influencing the success or failure of parameters influencing the success or failure of an underground gasification project. Introduction One method of eliminating many of the technological and environmental difficulties encountered during the production of synthetic gas through aboveground coal gasification involves gasifying cod in situ. This process, known as underground coal gasification, was first proposed in 1868 by Sir William Siemens and is based on the controlled combustion of coal in situ. This in-situ combustion results in the production of an artificial or synthetic gas that is rich in carbon dioxide, carbon monoxide, hydrogen, and hydrocarbon gases. Despite the fact that reaction stoichiometry is a moot element of underground coal gasification, it is nonetheless believed thatcarbon dioxide is formed by the partial oxidation of coal,carbon monoxide is generated by the subsequent reduction of carbon dioxide, andthe hydrogen and hydrocarbon gases result from the water-gas reaction and carbonization of coal, respectively. To effect the controlled combustion of coal in situ, the coal seam first must be ignited and a means must be provided for supporting combustion (through injection of a suitable gasification agent) and producing the gases generated underground. Fig. 1 presents a schematic diagram of an underground gasification system that complies with these requirements. This approach to gasifying coal is known as the stream or channel method and necessitates drilling two parallel galleries, one serving as an injection gas inlet and the other as a producer gas outlet. These wells are then linked by a borehole drilled horizontally through the coal seam. Ignition occurs in the coal seam at the gas inlet and proceeds in the direction of flow. The combustion front thus generated moves essentially perpendicular to the direction of gas flow. perpendicular to the direction of gas flow.Since the technological inception of underground gasification, over 1,500 publications have appeared in the literature that bear testimony to the absence of a complete, legitimate, theoretical analysis of the underground gasification process. Given this observation, it is the basis of this paper that progress in underground coal-gasification research progress in underground coal-gasification research has suffered from the absence of "interpretative theory"; that is, it has suffered from a lack of logical, physical, and mathematical analysis of the governing and underlying aerothermochemical principles. The difficulties in formulating a principles. The difficulties in formulating a mathematical model adequately describing the numerous phenomena involved during coal gasification are indeed formidable. SPEJ P. 425

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.

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