TY - JOUR
T1 - Experimental study on evaluation of underground coal gasification with a horizontal hole using two different coals
AU - Hamanaka, Akihiro
AU - Su, Fa qiang
AU - Itakura, Ken ichi
AU - Takahashi, Kazuhiro
AU - Kodama, Jun ichi
AU - Deguchi, Gota
N1 - Funding Information:
This work was supported by Mikasa City, the Japanese Society on UCG, State Key Laboratory for GeoMechanics and Deep Underground Engineering, China University of Mining & Technology: SKLGDUEK2004, Key Laboratory of Western Mine Exploitation and Hazard Prevention, Ministry of Education: SKLCRKF1902, and JSPS KAKENHI Grant Number JP21K14575. The authors gratefully acknowledge their support, and expresses particular appreciation to UCG project members.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Underground coal gasification (UCG) is a technique to extract coal energy with heat energy and combustible gases through chemical reactions in the underground gasifier. In this study, an application of a coaxial UCG system with a horizontal hole is discussed by means of the model UCG experiments with a large-scale simulated coal seam having dimensions of 550 × 600 × 2740 mm. The two types of coal having 30.18 MJ/kg of calorific value with 7.9% of ash (type 1) and 22.66 MJ/kg of calorific value with 28.3% of ash (type 2) were used for the experiments to evaluate the effect of coal quality on temperature distribution of the gasification area and product gas quality. The oxygen-enriched air was used. The injection rate of the gasification agents was elevated during the experiments to analyze the effect on the product gas. The results show that the gasification area is expanded along the wall of a coaxial hole, not upwards for the type 2 coal with high ash content. The average calorific value of product gas for types 1 and 2 is 8.05 MJ/m3 and 6.91 MJ/m3 respectively, while an increase of injection flow rate produces an improvement of the calorific value for both types of coal. Additionally, it is suggested that the reacted carbon and the product gas volume can be estimated with the volume of oxygen injected regardless of the coal quality if the gasification efficiency and the reaction temperature are similar. These results help to estimate several important parameters, e.g. reacted coal amount, recovered gas volume, and recovered energy from the coal when the actual field implementation is designed.
AB - Underground coal gasification (UCG) is a technique to extract coal energy with heat energy and combustible gases through chemical reactions in the underground gasifier. In this study, an application of a coaxial UCG system with a horizontal hole is discussed by means of the model UCG experiments with a large-scale simulated coal seam having dimensions of 550 × 600 × 2740 mm. The two types of coal having 30.18 MJ/kg of calorific value with 7.9% of ash (type 1) and 22.66 MJ/kg of calorific value with 28.3% of ash (type 2) were used for the experiments to evaluate the effect of coal quality on temperature distribution of the gasification area and product gas quality. The oxygen-enriched air was used. The injection rate of the gasification agents was elevated during the experiments to analyze the effect on the product gas. The results show that the gasification area is expanded along the wall of a coaxial hole, not upwards for the type 2 coal with high ash content. The average calorific value of product gas for types 1 and 2 is 8.05 MJ/m3 and 6.91 MJ/m3 respectively, while an increase of injection flow rate produces an improvement of the calorific value for both types of coal. Additionally, it is suggested that the reacted carbon and the product gas volume can be estimated with the volume of oxygen injected regardless of the coal quality if the gasification efficiency and the reaction temperature are similar. These results help to estimate several important parameters, e.g. reacted coal amount, recovered gas volume, and recovered energy from the coal when the actual field implementation is designed.
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U2 - 10.1016/j.fuel.2021.121556
DO - 10.1016/j.fuel.2021.121556
M3 - Article
AN - SCOPUS:85111966060
VL - 305
JO - Fuel
JF - Fuel
SN - 0016-2361
M1 - 121556
ER -