Mixed oxidant high temperature corrosion in gasifiers and power plants

Slipstream Testing of Particulate Filters at the Wabash River Coal Gasification Repowering Project

“…9c) indicated again that the Fe-A1 matrix was being converted into Fe-S and oxide products. These results and the results of other analyses discussed above suggest that the iron diffuses outward to fill the pores with Fe-S, a conclusion that has also beea reached by others (Bakker and Stringer 1997). The corrosior products formed throughout the thickness of the filter and Fig.…”

ELCOGAS IGCC power plant in Spain: effect of the gasifier environment on the high alloy steel performance

“…Thus, protective parabolic corrosion kinetics can change to more linear rates due to repeated scale spallation [2]. Frequent scale spallation could be the major cause of accelerated corrosion rather than aqueous corrosion during downtime alone [3]. Moreover, according to some authors [4] the presence of sulphides on the scale and sulphide channels in the scale cause high susceptibility to dew-point corrosion during down-times of the plant.…”

“…Internal penetration occurs only if the reactive component of the substrate diffuses outwardly more slowly than the gaseous species diffuses inwardly. Some authors have reported parabolic corrosion kinetics of Sanicro 28 in coal gasification atmospheres, especially after long term exposure, and lower metal losses than other austenitic materials [3]. This has been attributed to the Mo content in the alloy.…”

“…The hot raw gas is very aggressive and corrosion of metal components can occur by oxidation/sulphidation at elevated temperatures during the operation, or by Down Time Corrosion (DTC) when the plant is cooled. This latter type of corrosion results from either acidic condensation from the syngas or hygroscopic deposits when the system is opened to the atmosphere [2,3].…”

“…Macroscopically such samples are characterized by extensive scale spallation [2,3]. Exposure to moisture during downtime tends to concentrate chlorides and aqueous corrosion products at the scale-metal interface that can cause spallation of the chromium oxide rich scales.…”