Developmental and environmental effects of the Kızıldere geothermal power project, Turkey

Calcite scaling in the wells and the high boron concentration in the produced fluids are a major problem in the Kızıldere geothermal field. Scaling is minimized by controlling wellhead pressures and by mechanically removing the deposits periodically. Silica scaling would be a potential problem were reinjection to be introduced. Currently the spent geothermal water is discharged into the nearby Büyük Menderes River, which might prove harmful to plants and crops downriver. The new disposal methods currently being developed include reinjection, removal of boron by chemical treatment, and transportation to the Aegean Sea. Technically and economically, reinjection seems to be the most suitable option, and might also improve steam production. Another potential environmental problem at Kızıldere is the high carbon dioxide content (1-3% by weight) in the produced fluid. This has a significant impact on the output of the power plant turbogenerator, and on the performance of its condenser. However, the gas discharged from the condenser has high purity, and is piped to an adjacent plant where minor impurities are removed. This plant currently produces 120,000 t/year of industrial-grade carbon dioxide, which provides more than 90% of Turkey's requirements for carbonated soft drinks. Thus, a potentially major environmental problem has been turned into a benefit.