Silica-enhanced sorbents for dry injection removal of SO/sub 2/ from flue gas
Novel silica-enhanced lime sorbents were tested in a bench-scale sand-bed reactor for their potential for SO/sub 2/ removal from flue gas. Reactor conditions were 64/sup 0/C (147/sup 0/F), relative humidity of 60 percent, and inlet SO/sub 2/ concentration of 500 or 1000 ppm. The sorbents were prepared by pressure hydration of CaO of Ca(OH)/sub 2/ with siliceous materials at 100/sup 0/C to 230/sup 0/C for 15 min to 4 h. Pressure hydration fostered the formation of a sorbent reactive with SO/sub 2/ from fly ash and Ca(OH)/sub 2/ in a much shorter time than did atmospheric hydration. The conversion of Ca(OH)/sub 2/ in the sand-bed reactor increased with the increasing weight ratio of fly ash to lime and correlated well with B.E.T. surface area, increasing with increasing surface area. The optimum temperature range for the pressure-hydration of fly ash with Ca(OH)/sub 2/ was between 110 and 160/sup 0/C (230 and 320/sup 0/F). The pressure hydration of diatomaceous earth with CaO did not offer significant reactivity advantages over atmospheric hydration; however, the rate of enhancement of Ca(OH)/sub 2/ conversions was much faster with pressure hydration. Scanning electron microscope (SEM) and x-ray diffraction studies showed solids of different morphology with different fly ash/lime ratios and changing conditions of pressure hydration.
- Research Organization:
- Acurex Corporation, Research Triangle Park, NC (USA)
- OSTI ID:
- 6636119
- Journal Information:
- J. Air Pollut. Control Assoc.; (United States), Vol. 38:8
- Country of Publication:
- United States
- Language:
- English
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Silica-enhanced sorbents from dry injection removal of SO2 from flue gas
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Related Subjects
54 ENVIRONMENTAL SCIENCES
CALCIUM HYDROXIDES
SORPTIVE PROPERTIES
FLUE GAS
DESULFURIZATION
SULFUR DIOXIDE
REMOVAL
AIR POLLUTION CONTROL
FLY ASH
SCANNING ELECTRON MICROSCOPY
SURFACE AREA
X-RAY DIFFRACTION
AEROSOL WASTES
ALKALINE EARTH METAL COMPOUNDS
ASHES
CALCIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
CONTROL
DIFFRACTION
ELECTRON MICROSCOPY
GASEOUS WASTES
HYDROGEN COMPOUNDS
HYDROXIDES
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
RESIDUES
SCATTERING
SULFUR COMPOUNDS
SULFUR OXIDES
SURFACE PROPERTIES
WASTES
010800* - Coal
Lignite
& Peat- Waste Management
500200 - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)