Zero Emission Geothermal Flash Power Plant

The successful exploitation of geothermal energy for power production relies on the availability of nearly zero emission and efficient technologies. Two zero emission flash plant layouts, with full reinjection of the geothermal fluid (non-condensable gas included), are considered. This paper focusses on the CO2 issue, and therefore only the carbon dioxide is considered as non condensable gas present in the geothermal fluid; the CO2 flow is separated, compressed, and reinjected with the geothermal fluid. Both the reservoir and the power plant are simulated. A first scheme of plant presents a conventional layout in which the CO2 is separated and compressed after the condenser. The second scheme presents a plant layout that allows the separation of the CO2 at higher pressure with respect to the conventional layout, thus reducing the requested power consumption. The conventional plant scheme performs always better at higher temperature and at lower concentration of CO2. The new layout results better for low temperature and higher gas content. (C) 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 72nd Conference of the Italian Thermal Machines Engineering Association