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Through proper design, coal mining operations can contribute to the social, economic and environmental aspects of sustainable development. The regulatory and permitting programmes for coal mining in the United States, which often focus on several largely environmental parameters, are barriers to holistic consideration of these three sustainability pillars. Some changes in the current US regulatory framework may be necessary to allow for systematic consideration of economic, environmental and social factors in order to achieve more sustainable development of mineral and energy resources. In the quest towards more sustainable mining activities, it has been suggested that mine design may be optimised in the context of sustainability using a systems engineering approach that simultaneously considers economic, environmental and social factors. The use of geographic information system (GIS) tools may aid in this approach by allowing for spatial analyses of various resources (e.g. mineral values, water resources, community infrastructure) and identification of potential areas of conflict between these factors. By GIS analysis of the on-the-ground issues related to sustainability, the key parameters to be considered in decision-making were identified. This type of analysis is crucial not only for regulatory compliance, but also to ensure that the operation has obtained the ‘social licence’ to mine. To demonstrate this approach, a case study was conducted on a mountaintop coal mining operation in central Appalachia. High-conflict areas were found to be primarily concentrated near streams and residential developments through the use of GIS. The case study suggests that use of this approach could have allowed for better communications and planning. The controversies surrounding permitting at the site, including litigation, could have also been avoided. Adoption of such a process could assist in the transition to a new regulatory framework that promotes and is based on sustainable development principles. [ABSTRACT FROM PUBLISHER]

Underground coal gasification (UCG) is an advancing technology that is receiving considerable global attention as an economic and environmentally friendly alternative for exploitation of coal deposits. UCG has the potential to decrease greenhouse gas emissions (GHG) during the development and utilization of coal resources. In this paper, the life cycle of UCG from in situ coal gasification to utilization for electricity generation is analyzed and compared with coal extraction through conventional coal mining and utilization in power plants. Four life cycle assessment models have been developed and analyzed to compare (greenhouse gas) GHG emissions of coal mining, coal gasification and power generation through conventional pulverized coal fired power plants (PCC), supercritical coal fired (SCPC) power plants, integrated gasification combined cycle plants for coal (Coal-IGCC), and combined cycle gas turbine plants for UCG (UCG-CCGT). The analysis shows that UCG is comparable to these latest technologies and in fact, the GHG emissions from UCG are about 28 % less than the conventional PCC plant. When combined with the economic superiority, UCG has a clear advantage over competing technologies. The comparison also shows that there is considerable reduction in the GHG emissions with the development of technology and improvements in generation efficiencies. [ABSTRACT FROM AUTHOR]

Temperature influence or geothermal effect is pervasive in the carbon dioxide geological sequestration, GIP (gas in place) estimation, and the Coal Mine Methane (CMM) degasification process. The temperature effects on the adsorption process are not explicitly considered in previous gas diffusion tests. This study seeks to treat the adsorption–diffusion process as a unified process and then investigate the temperature influence effect on this process. Isothermal tests under different constant temperatures show that 1) Langmuir constant-a is independent of temperature, and Langmuir constant-b can be treated as a negative linear function of temperature in engineering applications. Two groups of diffusion tests were conducted: diffusion under constant temperature and diffusion with increasing temperature. The diffusion tests show that 2) for the diffusion process with increasing temperature, the equivalent diffusion coefficient (D eq ) increases with increasing temperature, and this relationship can be described by the revised Arrhenius-style equation. 3) For the diffusion process under constant temperature, the diffusion coefficient (D) is dependent on temperature and independent of adsorption equilibrium pressure. The relationship between diffusion coefficient and temperature can also be described using the revised Arrhenius-style equation. 4) Diffusion coefficients range from 8.53 × 10 −8 cm 2 /s to 1.97 × 10 −7 cm 2 /s when temperature rises from 30 °C to 90 °C. [ABSTRACT FROM AUTHOR]