ENVIRONMENTAL LIMITATIONS FOR UNDERGROUND COAL GASIFICATION - THE LUBLIN COAL BASIN CASE STUDY (EAST PART OF POLAND)

Lublin Coal Basin (LCB) is one of three bituminous coal basins in Poland and is situated in the east part of the country. The area of LCB is about 1200 km(2). Within the basin, 11 coal deposits were discovered and assessed in the Lower Carboniferous Lublin Beds. Underground coal gasification (UCG) is a controlled coal burning. During the process of coal gasification a chemical reaction between gasifying medium and coal substance takes place. That method was lead at the beginning of the 20th century as alternative way for coal exploitation. It is many advantages of underground coal gasification, which may be an argument for development the UCG technology, e.g. efficiency, economic potential and possibilities of reducing negative impact of exploitation on environment. Basic geological conditions of coal occurrence, which determine the method are: internal structure of deposit (thickness, continuous layer, intercalations, etc.) hydrogeological conditions of deposit and environment, structure and thickness of the overburden, type and properties of surrounding rock and their changes after exploitation. The UCG method can generate danger by liquid and gas products of gasification such as phenols, CO, CH4, NHS, H2S, CO2. Usually investors do not pay enough attention to environmental hazards, e.g. atmosphere, underground water or rockmass and public safe as well. Environmental limitations (such as National Parks, landscape parks, Natura 2000 protected landscape'areas) are the most important factor which often may excludes projects of UCG installation. Within LCB about 35% of surface is under environmental protection.