Characteristics of HCl sorption reaction by CaO involved in coal ashes

The applicability of Ca-compounds involved in coal burnt ashes to dry gas s orbent for I ICI removal is experimentally studied. The experiments for HCl sorption are conducted bq employing different kinds of coal burnt ash disc harged from a fluidized bed coal combustor (FBC), circulating fluidized bed coal combustor (CFBC), and pulverized coal combustor (PCC), The experiment s were carried out with a packed bed of coal burnt ash 44-63 mm in mean dia meter, through which the HCl gas of initial concentration of 1,000 ppm was made to flow under atmospheric condition in the temperatures range of 473 t o 1,073 K. Experimental results show that the HCl conversion of coal burnt ash increas e with the increment of the amount of Ca-compounds contained in the ash. Th ere is an optimum temperature range between 673 and 873 K for HCl sorption for the employed ash samples. It is found that a part of Ca component did n ot show any reactivity for HCl sorption. Such Ca components, were considere d to be in the form of melted amorphous silicate, oxide and sulfate, in acc ordance with the element distribution analysis on the surface of ashes by S EM/EDX.