Quality of ashes produced in the co-combustion of coal and MBM in a fluidized bed reactor

Since the 90’s decade there are severe restrictions to the use of MBM, due to BSE. The co-combustion of Meat and Bone Meal (MBM) and coal is a possible energetic valorization route for MBM. However, the chemical and ecotoxicological properties of the ashes produced in this co-combustion process need to be more characterized. In order to evaluate the chemical and ecotoxicological properties of this type of ashes, three combustion tests were performed in a fluidized bed reactor (FBR): 1) combustion of coal; 2) co-combustion of coal and MBM; 3) combustion of MBM. The characterization of the ashes was focused on the following aspects: (1) the bulk content of metals; and (2) the chemical and ecotoxicological characterization of eluates. The ashes were classified according to their ecotoxicity levels based on the French regulation CEMWE. According to Council Decision (CD) 2003/33/EC, all fly ashes need stabilization prior to landfilling, except the 1st cyclone ash produced in the co-combustion test that could be landfilled in a hazardous waste landfill. The bottom ashes were classified as non-hazardous residues. The novelty of this paper is related with two aspects: 1) the use of MBM as co-fuel; and 2) both chemical and ecotoxicological characterization of the ashes produced during the combustion of coal and MBM.

(Available "on-line" at http://www.icrepq.com/icrepq'11/526-barbosa.pdf)