Different solutions to coat hot brine environment

Geothermal power plants are developed to harness the thermal energy stored within the earth’s crust. Quelle: Rainer Sturm/Pixelio

Our earth’s interior - like the sun - provides incredibly high amounts of energy. This source of energy - geothermal energy - yields warmth and power that we can use without polluting the environment. Geothermal power plants are developed to harness the thermal energy stored within the earth’s crust. One major disadvantage of geothermal plants is the need for expensive metals to manufacture extraction components like pipes and joints. These specific metals are required due to the high level of corrosion met at such deepness in the ground. The U.S. Department of Energies Office of Geothermal Technologies is managing a program dedicated to develop advanced coating material systems. These coatings should have upgraded corrosion-, erosion-, and fouling-prevention performances that extend the lifecycle of carbon steel-based plant components, including heat exchangers, heat exchanger tube/sheet or pipe/pipe joint areas, wellheads, condensers, and steam separators, which encounter very harsh geothermal environments. Poly (tetrafluoroethylene)/ (hexafluoropropylene) (PTFHFP) coating adequately protected the steel panel against corrosion. The carbon steel underwent hydrothermal oxidation. This leads to the formation of hydrophilic fluorocarboxylic acid. As a result the thermal stability of the coating was detriment and ionic conductivity was increased.