Berlin 2018 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 47: Poster Session II
MM 47.49: Poster
Mittwoch, 14. März 2018, 18:30–19:45, Poster C
Sulfation kinetics of alkali chlorides and subsequent chlorine induced corrosion in waste-to-energy plants — •Sebastian Pentz1, Daniel Ott1, Ferdinand Haider1, and Ragnar Warnecke2 — 1Universität Augsburg, Inst. f. Physik, 86159 Augsburg — 2Gemeinschaftskraftwerk Schweinfurt GmbH, 97424 Schweinfurt
High temperature corrosion leads especially in waste-to-energy-plants to massive problems. At prevalent temperatures around 500∘C-600∘C corrosion is mainly chlorine induced. Responsible for the supply of chlorine at heat exchangers like superheaters or boiler walls is in majority a local release of chlorine through sulfation of solid alkali chlorides. This reaction requires an atmosphere containing SO2, H2O, O2 and releases HCl/Cl2. In this work the sulfation kinetics for different parameters, like temperature, gas stream, gas components or the influence of catalytic additives is examined. The conversion rate is strongly dependent on the transformation of SO2 to SO3, which is catalyzed by the presence of iron oxides like Fe2O3. Further experiments are done with FeCl2 on top of the samples in order to directly release chlorine at the metal surface. In addition to the study of the sulfation reaction rate it is possible to characterize the metal loss of samples simultaneously. Furthermore the behaviour of chlorine during the process of the corrosion was investigated. Principles of the reaction conditions in waste-to-energy-plants, especially at the superheaters, are shown and laboratory experiments regarding the kinetics of sulfation reactions are presented.