High-Temperature Corrosion in Waste-to-Energy Boilers

There are 88 waste-to-energy (WTE) plants in the U.S. and over 600 worldwide. In total, they combust close to 143 million metric tons of municipal solid wastes (MSW) and generate about 45 billion kW · h of electricity and an equal amount of thermal energy for district heating and industrial use. The presence of various impurities, especially HCl and chloride salts, in the combustion gases results in much higher corrosion rates of boiler tubes and has led to the development of special alloys and also metal protection techniques, including high velocity oxygen fuel (HVOF) sprayed coatings. This study examines the corrosion mechanisms in WTE boilers and summarizes the findings of a corrosion survey of several WTE facilities in the U.S. The study also examines existing and potential methods for reducing corrosion problems.