As the South African economy relies heavily on its coal resources, these resources should be utilised and managed in the best possible manner. Underground coal gasification (UCG) is one of the leading technologies used where conventional mining techniques are uneconomical. UCG delivers gas suitable for synthesis, production of fuels and electricity or for home usage. The method is perceived as being environmentally friendly and safer than traditional mining. The study summarised in this paper was conducted so as to create a simple model that would allow for the evaluation of UCG process-related costs versus expected benefits in a wider context under different circumstances. The parameters of the model are: feasibility definition, i.e. maximum possible gas calorific value, based on geological surveys and gasification agents; direct process derived from the expected capital and operational expenditures and compared with the gas volume propensity; and assessment of externality costs. The externalities concept should encourage governmental agencies to consider investment in UCG technology as a vehicle for delivering, potentially, high savings in terms of expenditure on national health and of the reduction in the costs of environmental damage resulting from gaseous emissions into the atmosphere.
Abstracts in English and French accompanying a poster presentation of 20 slides delivered at the World Energy Congress, Rome, Italy, 2007.