Abatement of Hydrogen Chloride in Geothermal Power Plants

Abstract

Corrosion mitigation through the abatement of hydrogen chloride is one of the most important operations that must be carried out in some geothermal power plants. When chloride concentrations in the steam are higher than a few scrubbing of the steam is necessary to prevent corrosion of the gathering system and failure of the turbine blades. In the Larderello area, this operation is usually performed through direct injection of a caustic solution in the steam pipeline immediately upstream from the power plants. the last few years, static mixers have been used to reduce the length of pipeline necessary for the steam scrubbing to take place. In this paper, some simplified models are proposed for the calculation of the chloride abatement process in pipelines, static mixers, centrifugal separators and vane type demisters. The results obtained from these models are compared with the field data gathered from power plants operating the Larderello area.