Effect of Injection Flow Rate on Product Gas Quality in Underground Coal Gasification (UCG) Based on Laboratory Scale Experiment: Development of Co-Axial UCG System
Akihiro Hamanaka,
Fa-qiang Su,
Ken-ichi Itakura,
Kazuhiro Takahashi,
Jun-ichi Kodama,
Gota Deguchi
Affiliations
Akihiro Hamanaka
Department of Earth Resources Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
Fa-qiang Su
School of Energy Science and Engineering, Henan Polytechnic University, 2001 Century Avenue, Jiaozuo 454-003, Henan, China
Ken-ichi Itakura
Center of Environmental Science and Disaster Mitigation for Advanced Research, Muroran Institute of Technology, 27-1 Mizumoto, Muroran 050-8585, Japan
Kazuhiro Takahashi
Center of Environmental Science and Disaster Mitigation for Advanced Research, Muroran Institute of Technology, 27-1 Mizumoto, Muroran 050-8585, Japan
Jun-ichi Kodama
Division of Sustainable Resources Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, Japan
Gota Deguchi
Underground Resources Innovation Network, Kita 47 Higashi 17, Higashi-ku, Sapporo 007-0847, Japan
Underground coal gasification (UCG) is a technique to recover coal energy without mining by converting coal into a valuable gas. Model UCG experiments on a laboratory scale were carried out under a low flow rate (6~12 L/min) and a high flow rate (15~30 L/min) with a constant oxygen concentration. During the experiments, the coal temperature was higher and the fracturing events were more active under the high flow rate. Additionally, the gasification efficiency, which means the conversion efficiency of the gasified coal to the product gas, was 71.22% in the low flow rate and 82.42% in the high flow rate. These results suggest that the energy recovery rate with the UCG process can be improved by the increase of the reaction temperature and the promotion of the gasification area.
