Record Display for the EPA National Library Catalog


Main Title Fly Ash Recycle in Dry Scrubbing. Journal Article.
Author Jozewicz, W. ; Rochelle, G. T. ;
CORP Author Texas Univ. at Austin. Dept. of Chemical Engineering.;Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab.
Publisher c1986
Year Published 1986
Report Number EPA/600/J-86/553;
Stock Number PB91-182048
Additional Subjects Fly ash ; Calcium oxides ; Scrubbers ; Recycling ; Air pollution control ; Sulfur dioxide ; Stationary sources ; Inorganic silicates ; Slurries ; Spray drying ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB91-182048 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 8p
The paper describes the effects of fly ash recycle in dry scrubbing. (Previous workers have shown that the recycle of product solids improves the utilization of slaked lime--Ca(OH)2--for sulfur dioxide (SO2) removal by spray dryers with bag filters.) In laboratory-scale experiments with a packed-bed reactor, utilization was increased several-fold when the Ca(OH)2 was first slurried with one of several different fly ashes. The enhancement increased with the higher loading of fly ash--g fly ash/g Ca(OH)2. Much higher Ca(OH)2 utilization was achieved when silic acid was used instead of fly ash. Scanning electron microscopy supports the explanation that Ca(OH)2 and silica dissolve and reprecipitate as a more reactive calcium silicate. Other major constituents of fly ash have less or no effect at all on Ca(OH)2 utilization. The amount of calcium in the fly ash did not affect the overall SO2 removal after Ca(OH)2 was added. Slurrying for longer than 2 hours at higher than 60 C can improve the utilization of Ca(OH)2 slurried with fly ash.