What are the possible solutions for agglomeration?

Agglomeration problem mainly occurs on the fireside in the fluidized bed boilers. Agglomeration is basically the ash-related problem of biomass-fired boilers. Ashes which are formed from high-sulfur and low-ash fuel agglomerate if they are prone to sulfating condition for long time.

Additives such as sulfur, kaolin and ammonia sulfate can be used to reduce agglomeration on superheater tubes. It is reported that if kaolin is added to the bed material before the combustion, then this would surely resolve the problem of agglomeration. The problem can also be counteracted if ammonium sulfate or sulfur is added as a substitute of kaolin. The reactions between the additives such as sulfur and alkali chlorides form alkali sulfates and the chlorine are released into gas phase as HCl. The alkali sulfates have higher melting points than the corresponding alkali chlorides and will, therefore, have a smaller tendency to stick to the superheaters as deposits. The deposit formation and the corrosion potential of the superheaters can, therefore, be minimized.