2001 Volume 80 Issue 5 Pages 333-342
In order to reduce emission of unburnt gas (CO, hydrocarbon) from fluidized bed incinerators, porous alumina was used as a bed material instead of conventional bed material (sand). Polyethylene pellets were burnt in a bench-scale bubbling fluidized bed incinerator. Porous bed material was found to be effective not only for the reduction of unburnt gas emission but also thermal-NOx emission. The reduction of thermal-NOx was explained by the suppression of flame combustion in the freeboard due to increased combustion in the dense bed and enhanced horizontal mixing of carbonaceous material. The horizontal concentration profile in the freeboard became uniform when the porous particle was employed. The above results were explained by the capacitance effect (hydrocarbon capture by pore) of the porous material.
