| Title | Feasibility Analysis for a CO2 Purification Technology to Be Installed in Geothermal Power Plants |
|---|---|
| Authors | Ana MARTÃNEZ-SANTAMARÃA, Andrea HERNÃNDEZ-PEDRERO, Maryori C. DÃAZ-RAMÃREZ, Victor Jose FERREIRA, Ana M. LÓPEZ-SABIRÓN, Germán FERREIRA |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Feasibility, CO2, geothermal emission control, LCA, environmental indicators, GECO project |
| Abstract | Geothermal energy has showed a promising potential to be an alternative to the use of fossil fuels for the power production due to its lower environmental impact. Nevertheless, most geothermal power plants are not emission free and there are challenges related to the processes involved in the power production. Geothermal power plants release a certain amount of greenhouse gases contained in the steam. Non-condensable gases usually include CO2, N2, CH4, H2S and H2 in different proportions depending on the reservoirs. In order to minimize potential environmental impacts attributed to geothermal electricity generation, CO2 capture and purification can be applied. This type of actions may contribute to a cleaner production while providing an additional value product that may reduce the overall cost of energy provision. Geothermal Emission Control (GECO) is an international research project that started in 2018, funded by the EU through the H2020. As part of the GECO project, a CO2 purification technology that comprises two stages is proposed. Firstly, H2S is selectively removed by amine-based absorption. Then, the stream is dehydrated and CO2 is condensed and separated from the remaining more volatile components. The amount of recovered CO2, its purity and, specifically, the H2S content are the key parameters to allow for subsequent usage. In this study, firstly the effect of the operating variables of the system on these target parameters is analyzed by computer simulation. The results represent the baseline for the definition of the optimal operation parameters that permit a significant level of highly pure CO2 recovery, while reducing the H2S content to a few ppm. Then, this information will be used to define possible scenarios to be evaluated by means of life cycle assessment (LCA) methodology. Based on this approach, environmental burdens attributed to the selected operating scenarios will be useful to assess operating conditions and identify the more optimal ones in terms of technical and environmental criteria. |