Corrosion in the Kalina cycle : an investigation into corrosion problems at the Kalina cycle geothermal power plant in Húsavík, Iceland

Abstract

An overview of the utilization of geothermal energy in Húsavík Iceland is given. Corrosion is discussed in a theoretical manner, with references to the literature for examples of different mechanisms of corrosion. Samples taken from the Húsavík power plant were analyzed by SEM and X-ray EDS, the theory behind this method is discussed and the results are given. Ultimately the investigation into why there were corrosion problems was inconclusive but instructive. Hypotheses discussed in the conclusion, with ways to further investigate them, include: dissolution of micro-constituents in the ammonia environment, galvanic corrosion, stray current corrosion and erosion corrosion. Mild steel and aluminum seem to be inappropriate materials for Kalina cycle systems but several stainless steels (304, 316, nitronic 60 and duplex) as well as 6Al-4V titanium do not appear to suffer from corrosion.