Geothermal Emission Control

ended

GECO will advance in the provision of cleaner and cost-effective non-carbon and sulphur emitting geothermal energy across Europe and the World. The core of this project is the application of an innovative technology, recently developed and proved successfully at pilot scale in Iceland, which can limit the production of emissions from geothermal plants by condensing and re-injecting gases or turning the emissions into commercial products. To both increase public acceptance and to generalise this approach, it will be applied by GECO in four distinct geothermal systems in four different European countries: 1) a high temperature basaltic reservoir in Iceland; 2) a high temperature gneiss reservoir in Italy; 3) a high temperature volcano-clastic reservoir in Turkey; and 4) a low temperature sedimentary reservoir in Germany. Gas capture and purification methods will be advanced by lowering consumption of resources, (in terms of electricity, water and chemicals) to deliver cheaper usable CO2 streams to third parties. Our approach to waste gas storage is to capture and inject the soluble gases in the exhaust stream as dissolved aqueous phase. This acidic gas-charged fluid provokes the dissolution of subsurface rocks, which increases the reservoir permeability, and promotes the fixation of the dissolved gases as stable mineral phases. This approach leads to the long-term environmentally friendly storage of waste gases, while it lowers considerably the cost of cleaning geothermal gas compared to standard industry solutions. A detailed and consistent monitoring program, geochemical analysis, and comprehensive modelling will allow characterising the reactivity and consequences of fluid flow in our geologically diverse field sites letting us create new and more accurate modelling tools to predict the reactions that occur in the subsurface in response to induced fluid flow. Finally, gas capture for reuse will be based on a second stage cleaning of the gas stream, through amine separation and burn and scrub processes, producing a CO2 stream with H2S levels below 1 ppm, which is the prerequisite for most utilisation pathways such as the ones that will be applied within the project.