Prevention of bed agglomeration with iron oxide during fluidized bed incineration of refuse-derived fuels

Abstract

The present study was performed to evaluate the effect of iron oxide addition on the prevention of bed agglomeration during the fluidized bed incineration of refuse-derived fuels (RDFs) having different alkali contents. To investigate the extent of bed agglomeration as a function of the Fe 2 O 3 /(K 2 O+Na 2 O) molar ratio, a simulation was performed by using a thermodynamic equilibrium model. Based on this simulation, potassium (K) component exhibited a much higher affinity for iron (Fe) component than for silicon (Si) component, and the extent of agglomeration was remarkably reduced. Therefore, a small amount of iron oxide added to the bed effectively reduced the extent of bed agglomeration in the fluidized bed incineration process. Furthermore, the extent of agglomeration decreased as the molar ratio of Fe 2 O 3 /(K 2 O+Na 2 O) increased until unity was attained. In excess Fe 2 O 3 , no potassium silicate melts existed in the products, while the amount of sodium silicate melts remained constant.