Coal liquids distillation tower corrosion: correlation of on-stream monitoring with process variables at the Wilsonville, Alabama, SRC-1 pilot plant

Abstract

Corrosion incidents in the fractionation area of direct coal liquefaction pilot plants have been severe. The Wilsonville, Alabama Solvent Refined Coal (SRC)-1 pilot plant operators quickly identified chloride, a minor component of the feed coal, as a contributing factor to this corrosion. They also learned that adding sodium carbonate to the coal feed was an effective way to provide a short-term measure to reduce corrosion; however, processing conditions would not permit the addition of alkali salts in a commercial plant. The extent of the corrosion at the atmospheric distillation tower of the Wilsonville plant has been continuously monitored for over a year. The results are reported here. The corrosion behavior is correlated with operational and feedstock parameters. The information reported here provides a basis for related investigations dealing with the analysis of process samples and laboratory corrosion experiments.