Fly ash recycle in dry scrubbing

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Environ. Prof.; (United States)

DOI:https://doi.org/10.1002/ep.670050405· OSTI ID:6834096

Jozewicz, W; Rochelle, G T

Previous workers have shown that the recycle of product solids improves the utilization of slaked lime (Ca(OH)/sub 2/) for SO/sub 2/ 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)/sub 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)/sub 2/). Much higher Ca(OH)/sub 2/ utilization was achieved when silicic acid was used instead of fly ash. Scanning electron microscopy supports the explanation that Ca(OH)/sub 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)/sub 2/ utilization. The amount of calcium in the fly ash did not effect the overall SO/sub 2/ removal after Ca(OH)/sub 2/ was added. Slurrying for longer than 2 hours at higher than 60/sup 0/C can improve the utilization of Ca(OH)/sub 2/ slurried with fly ash.

• Research Organization: Dept. of Chemical Engineering, The Univ. of Texas at Austin, Austin, TX 78712
• OSTI ID: 6834096
• Journal Information: Environ. Prof.; (United States), Journal Name: Environ. Prof.; (United States) Vol. 5:4; ISSN EPROD
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOL WASTES
AIR POLLUTION CONTROL
ALKALINE EARTH METAL COMPOUNDS
ASHES
BAGHOUSES
BENCH-SCALE EXPERIMENTS
CALCIUM COMPOUNDS
CALCIUM HYDROXIDES
CALCIUM SILICATES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMICAL REACTORS
CONTROL
DESULFURIZATION
DISPERSIONS
DISSOLUTION
DRY SCRUBBERS
DRYING
ELECTRON MICROSCOPY
EQUIPMENT
FABRIC FILTERS
FILTERS
FLY ASH
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
MICROSCOPY
MINERALS
MIXTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PACKED BED
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
RECYCLING
REMOVAL
RESIDUES
SCANNING ELECTRON MICROSCOPY
SCRUBBERS
SCRUBBING
SILICA
SILICATES
SILICIC ACID
SILICON COMPOUNDS
SILICON OXIDES
SLURRIES
SPRAY DRYING
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUSPENSIONS
WASTES