Eco-efficiency of underground coal gasification (UCG) for electricity production

• Life cycle assessment and life cycle costing of underground coal gasification were estimated.
• Eco-efficiency analysis of UCG considered Polish conditions.
• The main determinants of eco-efficiency UCG were reported.
• Availability of installation to produce electricity has the biggest influence on UCG eco-efficiency.

Hard coal is one of the main fossil fuels used to produce electricity in the world. Its combustion in power plants is associated with emissions of gas and dust pollutants. The article presents results of eco-efficiency assessment, life cycle assessment (LCA) and life cycle costing (LCC) of underground coal gasification (UCG) with the shaftless method and sensitivity analysis of eco-efficiency of electricity production from UCG. Eco-efficiency analyses considered Polish conditions. Results of LCA consider such damage categories as: impact on human health, quality of an ecosystem and use of resources. The largest impact on damage categories was caused by CO2 emission from syngas combustion and electricity consumption. Based on LCC results was concluded that for cost effective production of electricity with UCG it is necessary to maximise the scale of an installation while optimising use of the produced electricity. Through combusting UCG syngas in existing power plants, combined heat and power plants or heat plants, as well as electricity producing for own needs of a mine which enables avoiding transmission fees, which are actions increasing competitiveness of UCG technology. Sensitivity analysis showed, that the main determinants of eco-efficiency of producing electricity with UCG are availability of an installation to produce electricity and thickness of a coal seam.