Characterization of Sb scaling and fluids in saline geothermal power plants: A case study for Germencik Region (B\"uy\"uk Menderes Graben, Turkey)

TL;DR

This paper investigates the formation of stibnite scaling in the Germencik geothermal field in Turkey, identifying its impact on energy extraction and proposing an optimal reinjection temperature to mitigate scaling issues.

Contribution

It provides a detailed characterization of Sb scaling in a saline geothermal system and suggests operational strategies to prevent scaling in geothermal power plants.

Findings

Stibnite scaling significantly reduces energy efficiency in the GGF.

Optimal reinjection temperature to prevent Sb scaling is identified as 95°C.

Geological and chemical analysis informs scaling mitigation strategies.

Abstract

Turkey is located on the seismically active Alpine-Himalayan belt. Although tectonic activity causes seismicity in the Anatolian plate, it also constitutes an important geothermal energy resource. Today, geothermal energy production is heavily concentrated in Turkey's Western Anatolia region. Graben systems in this region are very suitable for geothermal resources. The B\"uy\"uk Menderes Graben (BMG) is an area of complex geology with active tectonics and high geothermal potential power. Germencik (Aydin) is located in the BMG, where the geothermal waters include mainly Na-Cl-HCO3 water types. This study examined the stibnite scaling formed in the preheater system of the Germencik Geothermal Field (GGF). The formation of the stibnite scaling on the preheater system dramatically reduces the energy harvesting of the GGF. Considering the stibnite scaling in the surface equipment, the optimum reinjection temperature was determined as 95 $^\circ$C to prevent stibnite scaling in the GGF.