FUEL TREATMENT FUNDAMENTALS (Amtek Research Inc. Canada)
Back End Corrosion
Fuel oils containing Sulfur cause back end corrosion in the Economizers, Air Heaters and the chimney. The cause of corrosion is the presence of Sulfuric Acid, which is formed in the following manner:
S + O2 -->SO2
SO2 + ½ O2 --> SO3
This reaction is catalyzed by Fe (Fe2O3) and V (V2O5), which are normally present in the fuel oil. Excess Air (Oxygen) is the biggest cause for the formation of SO3 in the flame zone.
Normally 1-5 % of SO2 gets converted into SO3. This can react with the water vapor of the flue gas and form Sulfuric Acid-which is corrosive.
SO3 + H2O --> H2SO4
Corrosion Inhibitors are standard treatment for Sulfur caused back end corrosion. |
