Characteristics of migration and speciation of trace elements during co-processing of antibiotic residues in a circulating fluidized bed

In order to study the emission characteristics of the products during the blending of antibiotic residues in coal-fired power plants, blending tests were performed on a 140 t/h circulating fluidized bed boiler. It was found that during combustion, 64 to 87.6% of Cr, As, and Pb are concentrated in the fly ash, and 11.4 to 35% are concentrated in the bottom ash. Only a small amount of these elements are captured by the desulfurization system or enter the environment. During the material distribution of the desulfurization system, trace elements are mostly concentrated in gypsum. In the desulfurization system, the proportion of Cr, As, Pb, Be, Mn, Co, Ni, Se, and Mo in the gypsum range from 82.8 to 99.9%, and the content has reached the level of ppm. When the blending ratio is controlled within 7%, the blending of antibiotic residues has little effect on the elemental composition of coal. The contents of Cr, Ni, Cu, Zn, and Ba in the products increased by 9.5 to 22.3%. This may mean when the blending ratio is increased, it will be harmful to the environment.

Automated summary

During combustion, a large proportion of elements such as chromium, arsenic, and lead are concentrated in fly ash or bottom ash, with only a small amount being captured by the desulfurization system or entering the environment. The blending of antibiotic residues has little effect on the elemental composition of coal, but increasing the blending ratio may be harmful to the environment.