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Main Title Investigation of Product-Layer Diffusivity for CaO Sulfation.
Author Borgwardt, R. H. ; Bruce, K. R. ; Blake, J. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab. ;Acurex Corp., Research Triangle Park, NC.
Year Published 1987
Report Number EPA/600/J-87/279;
Stock Number PB88-185509
Additional Subjects Calcium oxides ; Sulfur dioxide ; Diffusion ; Air pollution ; Chemical reactions ; Sulfation ; Limestone ; Particles ; Temperature ; Mathematical models ; Tables(Data) ; Reprints ;
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NTIS  PB88-185509 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
Abstract The paper gives results of comparisons of the sulfation rates of CaO prepared from Ca(OH)2 and CaCO3, using six types of each precursor derived from the same natural limestones. The particles were small enough to eliminate all transport resistances except diffusion through the CaSO4 product layer. No significant difference between the reactivity of the two types of CaO was observed when compared at equal values of specific surface area (23 sq m/g), temperature (800C), and SO2 partial pressure (304 Pa). The apparent product-layer diffusivity at these conditions was 2.1 x 10 to the minus 8th power sq cm/sec. For an activation energy of 33 kcal/mol, the Arrhenius pre-exponential factor for diffusion is estimated to be 0.12 sq cm/sec. Sulfation rates increased with the 0.64 power of SO2 partial pressure. (Copyright (c) 1987 by the American Chemical Society.)
Supplementary Notes Pub. in Industrial and Engineering Chemistry Research 26, p1993-1998 1987. Prepared in cooperation with Acurex Corp., Research Triangle Park, NC.
NTIS Title Notes Journal article.
Title Annotations Reprint: Investigation of Product-Layer Diffusivity for CaO Sulfation.
PUB Date Free Form c1987
Category Codes 68A; 99A
NTIS Prices PC A02/MF A01
Primary Description 600/13
Document Type NT
Cataloging Source NTIS/MT
Control Number 814621227
Origin NTIS
Type CAT