Superheater deposits and corrosion in temperature gradient – Laboratory studies into effects of flue gas composition, initial deposit structure, and exposure time

The heterogeneous nature of the ash chemistry biomass fuels gives rise to challenges in predicting deposit melting, sintering, and enrichment corrosive species. An experimental method has been developed study evolution morphology temperature gradients simulating conditions real superheater deposits. is based on applying synthetic mixtures an air-cooled corrosion probe, which inserted into a tube furnace. focus how melting behavior alkali salt-rich deposits, i.e., KCl–K2SO4–NaCl–Na2SO4 mixtures, affects morphology. Intradeposit vaporization-condensation chlorides interest. interaction reactive gas components (H2O + SO2), with was also studied. mechanism leads crevices voids within leading build-up steel surface, causes accelerated corrosion, due formation low-melting FeCl2 mixtures. Liquid phase sintering gradient zone (TGZM) were main mechanisms for supersolidus Iron nickel oxides found deposits at outer edge TGZM mechanism.