Record Display for the EPA National Library Catalog

RECORD NUMBER: 13 OF 35

OLS Field Name OLS Field Data
Main Title Evaluation of Problems Related to Scaling in Limestone Wet Scrubbing.
Author Berkowit, Joan B. ;
CORP Author Little (Arthur D.), Inc., Cambridge, Mass.
Year Published 1973
Report Number EPA-68-02-0215; R2-73-214;
Stock Number PB-221 159
Additional Subjects ( Scrubbers ; Scaling) ; ( Limestone ; Scrubbers) ; ( Sulfur dioxides ; Adsorption) ; ( Air pollution ; Sulfur dioxide) ; Calcium carbonates ; Reaction kinetics ; Chemical equilibrium ; Performance evaluation ; Sulfur trioxide ; Scale(Corrosion) ; Oxygen ; pH ; Limestone scrubbing ; Alkaline scrubbing ; Wet methods
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB-221 159 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 158p
Abstract
The report defines the relationship between scale formation and scrubber chemistry, based on thermodynamic analyses and bench-scale scrubber experiments, and includes a review of scaling problems in limestone wet scrubbing systems. It is assumed that mechanical scale deposition (due to wet/dry interfaces, stagnant areas, or poor gas/liquid distribution) can be controlled by good engineering design. Approaches to controlling chemical scale deposition are: pH control, highL/G, seeding, high residence time in a holding tank, temperature control, and oxidation control. It is shown that SO2 removal efficiency is a linear function of pH for 0.5% CaSO3 slurries, 0.5% CaCO3 and 0.6% limestone slurries, and 1% CaCO3 slurries. The CaCO3 scrubbing system is non-scaling, but removal efficiencies are limited by the SO3/HSO3 equilibrium to about 50%. In CaCO3 scrubbers, SO3 scaling can be minimized. A 100-125F temperature increase seems to increase the rate of scale deposition and, in the presence of O2, can lead to catastrophic scaling via a cementing reaction initiated by the precipitation of anhydrite. (Modified author abstract)