Chapter Ⅰ Introduction 1.1 Importance of Coal 1.2 Underground Coal Gasification Technology 1.3 Syngas in Power Generation Coupled with CO~ Capture 1.4 Risks of Groundwater Pollution Associated with UCG 1.5 Motivations and Obiectives Chapter Ⅱ Fort Unionlignite in North Dakota 2.1 Williston Basin and the Fort Union Lignite in North Dakota 2.2 Depositional Environment of the Fort Union Lignite 2.3 CO2 Utilization and Storage Potential in the Williston Basin Chapter Ⅲ Characterization of the Selected Sites 3.1 UCG Site Selection Criteria 3.2 Tools and Data in Site Screening 3.3 Selected Sites in Golden Valley County and Slope County, North Dakota 3.4 Selected Site in Dunn County, North Dakota 3.5 CO2 Market in the Selected Area Chapter Ⅳ Geomechanical Study on the Surrounding Rocks 4.1 Coupled Mechanisms in the UCG Process 4.2 Analogue to Tunneling and Longwall Mining 4.3 Geomechanical Testing 4.4 Interpretation of Test Results 4.5 Rock Behavior at High Temperatures Chapter Ⅴ Cavity Stability and Recovery Factor 5.1 Concept of UCG Plant of Commercial Scale 5.2 Assumptions of the Gasification Cavities 5.3 Governing Equations 5.4 Safety Concerns and Mining Recovery 5.5 Numerical Modeling Chapter Ⅵ Syngas Processing and Power Generation 6.1 Process Description 6.2 Modeling Results and Plant Performance Chapter Ⅶ Discussion and Conclusions References