The injection of CO2 to hypersaline geothermal brine: A case study for Tuzla region. (July 2019) - Topcu, Gokhan
Highlights: The recent field conditions of Tuzla Geothermal Power Plant were presented. CO2 was injected to a large-scale system to minimize metal-silicate scaling. Effects of CO2 were examined in terms of corrosion and solubility of metal-silicate. The results were compared to formic acid that is widely used as an anti-scalant. CO2 increases the solubility up to 18% and exhibits no corrosive effect. Abstract: Scaling is a serious issue for geothermal power plants since it remarkably decreases the harvesting of energy. The reduction of pH by organic acids whose structure is close to CO2 for instance formic acid has been an effective solution for the minimization of scaling. Herein, the effect of CO2 injection on the formation of scaling particularly metal-silicates was investigated for the model case of Tuzla Geothermal Field (TGF) located in the northwest of Turkey. CO2 has an acidic character in aqueous systems because it leads to the formation of carbonic acid. The injection of 20.6 m 3 /s CO2 (approximately 88 ppm) to hypersaline brine of TGF is a promising green approach for both mitigation of scaling by reducing pH from 7.2 to 6.2 at the well-head and the minimization of potential corrosion compared to the use of formic acid (55 ppm).