Environmental assessment of underground coal gasification in deep-buried seams

This study presents a preliminary assessment of the environmental impact field-scale underground coal gasification (UCG) targeting deep-buried seams by studying fate UCG products in reactor vicinity. A series simulation scenarios are conducted three deep (900 m) areas specific interest – namely, South Wales coalfield (UK), Upper Silesian basin (Poland) and Ruhr mining district (Germany) to investigate transport gaseous dissolved chemicals. The results indicate that syngas propagation is limited 2.0 m vicinity after 30 days, except it 4.4 shale (overburden) UK site. Transport chemicals, through diffusion, without considering adsorption less than 0.5 when considered 10 years. Moreover, effects hydrology condition, stratum properties thermally induced change rock porosity permeability on studied. suggest unacceptable risks environment unlikely arise if standard operating conditions applied, offering great prospect be for UCG. also provides insights into evaluation other potential projects.