Optimizing geothermal brine for balneological use: An integrated study of health, engineering, social, and economic dimesion

Abstract

Backgorund: Central Java has the only high-enthalpy Geothermal Power Plant complex located in Dieng. The geothermal reservoir stretches across Sileri in the northwest, Sikidang, and Pakuwaja in the southeast. The Dieng area possesses tremendous geothermal energy potential, However, only 10.3% or around 60 MW of its potential is utilized. At the moment, there is still a resource that has not been utilized, namely waste heat. Waste heat appears in the form of liquid-phase hydrothermal (brine) with a pH range of 6-7 and a temperature value of 180°C. The energy from the brine has the potential to be a source of water heating in hot spring facilities (balneology) with the help of heat exchanger technology. Methods: This study utilized a treatment process for geothermal brine involving coagulation with Poly Aluminum Chloride (PAC) at a concentration of 10 ppm and a pH adjustment to 8, combined with 1 ppm Polyamide flocculant. Then, the neutralized brine is used in the heat exchange system for balneology. The enthalpy of the geothermal working fluid is transferred to the heat pump working fluid (refrigerant) through the heat exchanger coil, causing the refrigerant to vaporize. Afterward, the refrigerant vapor is compressed to increase pressure and temperature. This high-temperature refrigerant is passed through the condenser pipe to warm the water in the balneology. Findings: As a result, the hot water from the heat exchange process has a temperature of less than 40°C and can be for hot baths. Hot baths can have physiological effects on the human body by inducing significant improvements in macro and microvascular functions. The habit of taking a hot bath has a good impact on health, giving adequate sleep quality, lowering stress levels, and increasing happiness. The scheme of utilizing brine for balneological facilities can also enrich the tourism aspect of Dieng, open doors to economic activity, and improve social standards for the surrounding community. Conclusion: Utilizing waste heat from geothermal brine through treatment with PAC and polyamide flocculant for balneological hot springs is a promising method for harnessing geothermal energy while addressing crustal issues. This approach provides health benefits, supports tourism development, and opens up economic opportunities that improve community well-being. Novelty/Originality of this article: This method integrates geothermal energy utilization with health and tourism benefits, offering a multidisciplinary contribution to sustainable socio-economic development in geothermal areas