Limitation of sulfur dioxide removal in a FGD spray dryer using once through slaked lime

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6950992

Dantuluri, S R

The present study discusses the importance of slaking operation and its effect on the removal efficiency in a spray dryer operated FGD system using slaked lime slurry. Laboratory scale slaking experiments were run to look into various characteristics of resulting slurry. Pilot plant tests were made to quantify the effects of different parameters on spray removal efficiency. A vertical tower mill was used to grind calcium hydroxide slurry to attain smaller particle size. X-ray diffraction and SEM techniques were used to visualize the crystallinity and surface area measurements were made for different slurries and an attempt was made to relate these parameters with the sorbent's performance in removing SO[sub 2] across the spray dryer. The findings of the present work indicate that increasing the surface area beyond certain values, the spray system can be operated under gas-phase controlled conditions, which should give maximum possible efficiency. The new version of the model SPRAYMOD-N was used to mimic these conditions to arrive at the gas phase controlled efficiency and corresponding particle size to achieve those conditions. It is found that slaked lime slurry particles around 2.3 microns size can give an efficiency of around 75 percent in the spray dryer for an inlet SO[sub 2] concentration of 1000 ppm, operated at a stoichiometric ratio (SR) of one and saturation approach temperature of 20F. Pilot tests conducted in this study with 2.4 micron Ca(OH)[sub 2] slurry achieved this efficiency. Predicted efficiency values (with constant rate period only) fell off at higher SR values, showing the significance of the falling rate period at those conditions.

• Research Organization: Tennessee Univ., Knoxville, TN (United States)
• OSTI ID: 6950992
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ALKALINE EARTH METAL COMPOUNDS
BENCH-SCALE EXPERIMENTS
CALCIUM COMPOUNDS
CALCIUM HYDROXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DESULFURIZATION
DIFFRACTION
DISPERSIONS
DRYING
EFFICIENCY
ELECTRON MICROSCOPY
FLUE GAS
FUNCTIONAL MODELS
GASEOUS WASTES
HYDROGEN COMPOUNDS
HYDROXIDES
MATHEMATICAL MODELS
MICROSCOPY
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PILOT PLANTS
REMOVAL
SCANNING ELECTRON MICROSCOPY
SCATTERING
SIZE
SLURRIES
SPRAY DRYING
STOICHIOMETRY
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE AREA
SURFACE PROPERTIES
SUSPENSIONS
WASTES
X-RAY DIFFRACTION