Thermodynamic analysis of the utilization of low enthalpy geothermal energy in Honduras using a Kalina cycle

Abstract

Low-enthalpy geothermal energy (30–101 °C) in Honduras remains an underutilized resource, primarily exploited only for balneology, despite its potential for national energy diversification. This study develops a thermodynamic analysis of the Kalina Cycle (KCS-11), which uses an ammonia-water binary mixture, to evaluate its performance in converting low-temperature geothermal resources. The methodology examined the influence of turbine inlet pressure (5–40 bar) and ammonia concentration (0.5–0.9) on cycle efficiency. The results show that thermal efficiency increases with pressure, achieving maximum theoretical values close to 12% in the 30 to 40 bar range and with ammonia concentrations between 0.7 and 0.9. These findings suggest that the KCS-11 is a promising alternative for utilizing low-enthalpy geothermal resources in Honduras. However, future work should incorporate exergy analysis and explore advanced cycle configurations, such as double regeneration schemes, while further characterizing the thermal properties of the country's low-enthalpy geothermal reservoirs.