Evaluation of Alloy Components from a Biomass Gasifier

Commercial alloy tube components from a biomass gasifier were removed to quantify the extent of corrosion. The Fe- and Ni-base outer tubes exposed to the fluidized bed of the gasifier were carburized during exposure with a metal temperature of ~700°C. Both chromia- and alumina-forming inner tubes were used to shield the combustion flame from overheating the outer tubes and were exposed to a higher temperature oxidizing environment. The Cr and Al depletion profiles from the inner tubes will be compared to laboratory exposed specimens to estimate the average exposure temperature.