Severe corrosion of steel and copper by strontium bromide in thermochemical heat storage reactors

Thermochemical heat storage exploits thermal solar energy to produce sustainable residential heating, obtained by exothermal reaction between bromides and water vapour. A protocol to test the corrosion of surrounding materials is discussed in the case of SrBr2 contacting copper or steel. Corrosion depth > 1 mm y (-1) is found for steel in conditions where the salt remains mostly solid, due to a reaction between SrBr2 and atmospheric CO2 that produces HBr. Temperature and the dissolution of the salt (deliquescence) also play a key role. Potentiodynamic tests, the limitations of which are discussed, corroborate the salt degradation in the case of steel.