Examination of the solubility of carbon dioxide in the geothermal fluids

In this thesis, dissolution of carbon dioxide emitted from geothermal plants within water reinjected to the geothermal reservoir and its reinjection are investigated. The aim of thesis was to protect the environment and prevent the geothermal managements from paying carbon tax and take a share from the carbon revenues. Also, during the research and studies; it was noticed that in case carbon dioxide is not injected to the reservoir, a decrease in carbon dioxide partial pressure decreases the production of wells although reservoir pressure and temperature are kept constant. Thus carbon dioxide reinjection of the geothermal reservoirs is very beneficial for protection of environment and sustainable production as well. Differing from several carbon sequestration projects, in this study carbon dioxide is injected to the reservoir not in the gas phase but following dissolved in the reinjected water. Carbon dioxide dissolves in water easily and rapidly. In the thesis, carbon dioxide emitted to the atmosphere from the geothermal plant is pumped with a compressor into the injected water and compressed up to a value that is above the dissolution pressure and then pumped to injection well. Increasing pressure in the well, pumping and compressor increase the operating costs. In order to lower operating costs and decrease the reinjection pressure, dissolution of whole carbon dioxide to be pumped within the whole injected water is the cost efficient solution. If the thesis is applied to geothermal fields, carbon dioxide-emitting geothermal managements will receive carbon reduction revenue, get rid of paying carbon tax and since carbon dioxide partial gas pressure will be maintained, productivity of the wells will increase thus much more energy will be produced from the field.