Prevention of chloride corrosion in biomass boilers by means of SO3 injection
Zapobieganie korozji chlorkowej w kotłach spalających biomasę za pomocą wtrysku SO3
Tomasz Hardy, Maciej Jakubiak, Krzysztof Filipowski
Streszczenie
The paper presents most developed methods of prevention of chlorine corrosion of steam superheater tubes
during biomass combustion which are based on alkali chlorides sulphation and formation less corrosive sulfates. A new
concept of using pure gaseous SO3 for sulphation process of KCl (being one of the main promoters of chloride corrosion) has
been described. In currently used methods of limiting chloride corrosion, the addition of sulfur (or its compounds) is used
mainly. Sulfur is converted to SO2 and SO3, with SO3 playing the most important role in sulphation of KCI. By introducing
the additive directly into the furnace in the SO3 form it is possible to obtain the effect of KCl sulphation with a limited sulfur
consumption in the process. Moreover, lower sulfur-based additive dosage shall limit the risk of occurrence of low
temperature corrosion. The possibilities of locating nozzles for SO3 dosing, taking into account the main limitations were
also presented.
during biomass combustion which are based on alkali chlorides sulphation and formation less corrosive sulfates. A new
concept of using pure gaseous SO3 for sulphation process of KCl (being one of the main promoters of chloride corrosion) has
been described. In currently used methods of limiting chloride corrosion, the addition of sulfur (or its compounds) is used
mainly. Sulfur is converted to SO2 and SO3, with SO3 playing the most important role in sulphation of KCI. By introducing
the additive directly into the furnace in the SO3 form it is possible to obtain the effect of KCl sulphation with a limited sulfur
consumption in the process. Moreover, lower sulfur-based additive dosage shall limit the risk of occurrence of low
temperature corrosion. The possibilities of locating nozzles for SO3 dosing, taking into account the main limitations were
also presented.