Scale Formation in Geothermal Plants

Abstract

Scaling from geothermal fluids has been recognized as a major obstacle in the development of geothermal energy. In the present contribution a summary is presented of the main types of scales encountered in geothermal systems, the basic concepts of precipitation fouling/scaling are discussed and the various measures to mitigate the problem are descrybed. Emphasis is given to calcium carbonate, which is the most common scale type found in low-entlhalpy geothermal sytems. The use of scale inhibitors appears to be the most suitable method to control carbonate scaling, and brine acidification seems to be a valid option in controlling silica and sulphide scaling from high-enthalpy geothermal brines.