Carbon Dioxide Geological Storage Potential of the Baltic Sedimentary Basin

Industrial CO2 emissions and geological storage opportunities in Estonia, Latvia and Lithuania are studied within the framework of EU GEOCAPACITY and CO2NET EAST projects supported by European Commission through Framework Programme 6. The structure of the energy sector and socio-economic conditions vary considerably between these three countries. A total of 24 large (emitting more than 0.1 million tonnes (Mt) of CO2) industrial sources of CO2 emissions, registered in 2005 in the European Trading Scheme, consists of 11.5 Mt of CO2 from Estonia, 1.9 Mt from Latvia and 5.6 Mt from Lithuania. The highest amount of CO2 emission in Estonia is related to the oil shale used as the main fuel for power generation; the two largest Estonian power plants – Estonian and Baltic – produced respectively 7.7 and 2.25 Mt of CO2 in 2005 and 9.4 and 2.7 Mt of CO2 in 2007. CO2 emission from oil shale combustion is significantly higher in comparison with other fossil fuels as energy sources. This is why CO2 emission per capita in Estonia is about two times higher than the average value in Europe. The three Baltic States are located within the Baltic sedimentary basin, the thickness of which varies from 100 m in Northeast Estonia up to 1900 m in Southwest Latvia and 2300 m in West Lithuania. The most prospective formation for geological storage of CO2 is the Cambrian reservoir. 15 large structures have been identified in Latvia with a total capacity exceeding 300 Mt of CO2. The tightness of structures is evidenced by 40 years of successful operation of the Inčukalns Underground Gas Storage. Due to shallow setting, geological conditions in Estonia are unfavourable for CO2 storage. Therefore an option of transporting CO2 from Estonia via pipelines to one of the Latvian storage structures could be considered. Alternatively, the technology of CO2 trapping by sorption of oil shale ash is under development in Estonia. In Lithuania, the capacity of CO2 storage in Cambrian and Devonian structures as well as in oil fields is negligible, but CO2 solubility and mineral trapping is a long-term option.