Enhanced Geothermal System with captured CO2.

Abstract Post-combustion capture plants are widely studied because they represent a feasible solution to limit the CO 2 emissions from existing plant. They can be applied to power plants and to industrial plants. The captured CO 2 is transported to dedicated sites to be sequestrated. In this study, the captured CO 2 from a coal-fired power plant is exploited to extract the geothermal energy for subsequent electric production. The system of wells consists of one of injection in a geothermal source of about 200-300 °C and one of production from which the CO 2 exits at high pressure and high temperature. It is expanded in a turbine to extract part of the energy and it is cooled to be sent to the storage site. The cooling process exchanges heat with an Organic Rankine Cycle to convert the heat to electric power. The ORC plants are tested with five different substances: R245fa, HCFO, hexane, pentane, and Isobutane. The better performances are obtained with the latter two. [ABSTRACT FROM AUTHOR]