| Abstract |
Río Perlas Spa & Resort is located at the Central Region of Costa Rica, on the Navarro fault system. This hotel exploits the two known hot water springs in the vicinity, they are both sulphated and immature springs, and there is an opportunity to use them to heat sanitary waters. For this reason, a project is being proposed, which aims to drill a well to extract brine at a rate of 79 l/min, with temperatures between 80 °C and 90°C. By using PHREEQC Version 3, it was determined that calcite, dolomite and silica are the minerals most likely to precipitate. Several scenarios were simulated with variable temperatures (from 30 °C to 90 °C) and pH (from 7.5 up to the maximum determined in the field tests). As a model assumption, 1 atm pressure was set for every simulated scenario. Results show that chemical composition of brine #1 is likely to produce silica precipitate (53.4 mg/kg H2O ) and carbonates precipitate (10.7 mg/kg H2O ). By contrast, brine #2 could precipitate 18.3 mg/kg H2O of silica and 38.2 mg/kg H2O of carbonates. By reducing brine’s pH, carbonate formation could be suppressed, but this is not the case for silica. Brine #2 is less likely to produce silica precipitate, for this reason it is selected to feed the planned heating system. |