Article
Chemistry, Physical
Zhenyong Yin, Hao Xu, Yanpeng Chen, Tiantian Zhao, Jingjie Wu
Summary: Research on hydrogen production from coal gasification focuses on the formation of CO and H2 from coal and water vapor. Pure oxygen-steam gasification is used to improve gasification efficiency. The two-step gasification process involving coal pyrolysis and char gasification is an efficient method for hydrogen production.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Huan Liu, Wei Guo, Shuqin Liu
Summary: This study compares the techno-economic performance of UCG-H2 and SCG-H2, and finds that UCG-H2 has lower investment and cost advantages, especially without CCS. However, the economic feasibility of UCG-H2 is challenged when hydrogen market prices are low.
Article
Energy & Fuels
Liangliang Jiang, Shanshan Chen, Yanpeng Chen, Zhangxin Chen, Fenjin Sun, Xiaohu Dong, Keliu Wu
Summary: Underground coal gasification (UCG) has the prospect of tapping deep coal seams and reducing carbon emissions. However, there is limited experience in deep UCG development. This study constructed a large-scale 3D UCG model with an improved method and considered the effect of double-diffusive natural convection. The results showed that the improved method was beneficial for the development of UCG cavities in deep coal seams, and double-diffusive natural convection played an important role in cavity development and overall UCG performance.
Article
Thermodynamics
Lin Xin, Mingyu An, Mingze Feng, Kaixuan Li, Weimin Cheng, Weitao Liu, Xiangming Hu, Zhigang Wang, Limin Han
Summary: This study simulated the pyrolysis process of lump coal in UCG tunnel, showing that with the increase of final pyrolysis temperature, the functional group content of coal samples decreased and the structure became more disordered.
Article
Green & Sustainable Science & Technology
Renato Zagorscak, Richard Metcalfe, Laura Limer, Hywel Thomas, Ni An, Alex Bond, Sarah Watson
Summary: This paper presents a flexible risk assessment methodology for Underground Coal Gasification (UCG) technology, which evaluates potential risks by analyzing various scenarios. The application of a numerical model suggests that the risks of groundwater contamination from a UCG site should be very low if the site is developed and operated appropriately.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Energy & Fuels
Fa-qiang Su, Tao Zhang, Jun-bo Wu, Qi-chao Deng, Akihiro Hamanaka, Yi-he Yu, Meng-jia Dai, Xiao-long He, Jun-nan Yang
Summary: In this paper, UCG simulation experiments were conducted to investigate the effects of the gasification agent ratio on the composition and calorific value of the product gas. An energy recovery evaluation method and an evaluation model of the underground coal gasification temperature field were established. The results showed that increasing the oxygen concentration improved the calorific value of the produced gas and the energy recovery rate.
Article
Energy & Fuels
Zhongfa Hu, Yangfan Peng, Fenjin Sun, Shanshan Chen, Yuegui Zhou
Summary: Underground coal gasification is a promising technology for converting coal resources into high-quality synthesis gas with low cost. The study found that gasification pressure and temperature have significant effects on the composition of synthesis gas, and increasing the oxygen/steam ratio enhances the contents of H-2 and CH4, as well as the low heating value of the synthesis gas.
Article
Green & Sustainable Science & Technology
Liangliang Jiang, Zhangxin Chen, S. M. Farouq Ali, Jiansheng Zhang, Yanpeng Chen, Shanshan Chen
Summary: Underground coal gasification (UCG) has great potential in extracting energy from deep coal seams with low environmental impact. CO2 storage in post-UCG cavities was found to be stable and effective. The findings will promote the application of UCG in deep coal seams worldwide and facilitate the transition of the coal industry towards carbon-consciousness.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Energy & Fuels
Wen-gang Huang, Zuo-tang Wang, Tian-hong Duan, Lin Xin
Summary: The pilot project integrating UCG with power generation in the abandoned mine Ankou aimed to optimize the gasification process, with industrial tests revealing that changes in oxygen concentration significantly affected syngas production. Increasing oxygen concentration led to higher H-2 content, combustible components, calorific value of syngas, and gasification efficiency after an initial drop. Additionally, oxygen-enriched gasification trials showed advantages in air consumption, coal consumption, and calorific value compared to oxygen-enriched steam gasification tests.
Article
Energy & Fuels
Hao Chen, Yong Qin, Yanpeng Chen, Zhen Dong, Junjie Xue, Shanshan Chen, Mengyuan Zhang, Yufeng Zhao
Summary: This study investigates the effect of oxygen content in oxygen-enriched carbon dioxide gasification agents on gasification experiment results. The results show that as the oxygen content increases, the CO and H-2 in the combustible gas increase gradually, as does the calorific value. Although the product formation rate and gas production per unit mass of coal fluctuate, the coal consumption rate remains relatively stable.
Article
Energy & Fuels
Akihiro Hamanaka, Fa-qiang Su, Ken-ichi Itakura, Kazuhiro Takahashi, Jun-ichi Kodama, Gota Deguchi
Summary: This study discusses the application of a coaxial UCG system with a horizontal hole through model experiments, evaluating the impact of coal quality on the temperature distribution of the gasification area and product gas quality.
Article
Chemistry, Physical
Huan Liu, Shuqin Liu
Summary: This study compares energy consumption and greenhouse gas emissions between underground coal gasification (UCG)-based hydrogen production (UCG-H-2) and surface coal gasification (SCG)-based hydrogen production (SCG-H-2) using life cycle assessment. Results show UCG-H-2 has significant energy saving advantage, and 80% capture rate can achieve a balance between energy consumption and emissions. Scenario analysis suggests UCG substitution for hydrogen production can reduce energy consumption significantly.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Green & Sustainable Science & Technology
Mingze Feng, Lin Xin, Zhigang Wang, Kaixuan Li, Jing Wu, Jiaze Li, Weimin Cheng, Bowei Wang
Summary: UCG technology, an innovative coal mining method, has not yet been widely applied due to complex geological conditions and control issues. The importance of gas tightness control in UCG and the challenges in maintaining it were discussed in this paper.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2021)
Article
Energy & Fuels
Maifan Dong, Lele Feng, Qigeng Zhou, Sibo Zhou, Xiangcen Xu, Botao Qin
Summary: This study investigates the concentration and composition of tar samples in underground coal gasification. The experiments show that the gasification agent and flow rate have a significant impact on the tar concentration and composition. Increasing the flow rate in oxygen gasification reduces the tar concentration at the reaction zone but increases it at the outlet, while increasing the flow rate in air gasification leads to a more uniform distribution of tar concentration and composition. Additionally, there are differences in tar concentration and composition between oxygen gasification and air gasification.
Article
Chemistry, Analytical
Fangjie Wu, Siyuan Huang, Qi Jiang, Guanchen Jiang
Summary: This study investigates the effects of heating rate and pressure on the char formation during the pyrolysis of bituminous coal. An empirical model is developed to predict pyrolysis rates under varying heating rate and pressure conditions. The results show that the optimal heating rate for char generation is around 10 degrees C/min and pressure above 2 MPa enhances char production.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
