Mitigation of Silicate-Stibnite Deposits in Reinjection Wells of Geothermal Power Plants
Abdurrahman Ünal and Y. Tuğçe Yüksel
R&D Center, Neuchemie, Tuzla, 34957, İstanbul, Tukey.
Abstract: Geothermal energy is an important resource for power and heat generation. The main operational handicap of geothermal power generation is scaling. As the mineral-rich underground waters rise to the well-head, the solubility of silica and minerals in the water decreases and precipitation occurs as the pressure and temperature decrease. In geothermal systems, an inorganic layer is formed on the inner surface of the pipe due to precipitation, called scale or deposit. This structure reduces the efficiency of energy harvesting as it reduces the internal diameter of the plant’s piping systems. Silica is one of the most frequently observed deposits encountered in geothermal systems. In addition, Stibnite (antimony sulfide) has been recently observed along with silica deposit in power plants located in the west coast of Turkey. In order to reduce the undesirable effect of the formation of both deposits as mixture (in fact this is the case in Kubilay geothermal system in Turkey), antiscalants need to be applied to the system to manage the scaling. The effect of antiscalants (A: acrylic homopolymer, B: carboxylic sulfone copolymer, C: carboxylic sulfone nonionic terpolymer), and the antiscalant composition (10 different mixtures) at 6.5 ppm has been examined in order to maintain the continuity of the efficiency of the power plants and to minimize the cleaning need of the system.
Keywords: antiscalants, scale, stibnite, silica.
Pages: 109 – 122 | Full PDF Paper