An experimental investigation of the mass-transfer mechanisms in sulfur dioxide absorption in lime solutions
The experiments were performed at gas temperatures from 24 to 114C using a wetted-wall column apparatus with SO[sub 2] concentrations ranging from 1800 to 7350 ppM, calcium concentrations of 2.82 [times] 10[sup [minus]6] to 1. 25 [times] 10[sup [minus]5] gmol/cm[sup 3], and column heights of 14 to 29 cm. Inlet SO[sub 2] content had a significant effect on rate of SO[sub 2] absorption, with the average absorption flux increasing with increasing SO[sub 2] gas concentration. Increasing gas temperature did not significantly affect the rate of SO[sub 2] absorption. Presence of lime in solution enhanced the average SO[sub 2] absorption flux and appeared to maintain the SO[sub 2] absorption capacity of the liquid, thereby negating the effect of decreasing SO[sub 2] solubility in water with increasing temperature. Slight increases in both the system's gas-phase resistances and enhancement factors were observed with increasing gas temperature. Under the conditions studied, the mass-transfer resistance in the SO[sub 2]-lime solution system was predominantly liquid-phase controlled, with observed gas-phase resistances ranging up to 42% of total. Comparison to literature shows that the system mass-transfer mechanism can be dominated by either the gas-phase resistance or the liquid-phase resistance, depending upon the gas-liquid contact times. Thus, results support the need to incorporate both gas- and liquid-phase mass-transfer resistances when modeling the absorption of SO[sub 2] in lime solutions and lime slurries, such as that occurring in the constant rate drying stage of the spray drying flue gas desulfurization process.
- Research Organization:
- Carnegie-Mellon Univ., Pittsburgh, PA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-76OR00033
- OSTI ID:
- 6823294
- Report Number(s):
- DOE/OR/00033-T518; ON: DE93005284
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
20 FOSSIL-FUELED POWER PLANTS
SULFUR DIOXIDE
ADSORPTION
AQUEOUS SOLUTIONS
CALCIUM HYDROXIDES
CALCIUM OXIDES
DESULFURIZATION
EXPERIMENTAL DATA
FLUE GAS
LIME-LIMESTONE WET SCRUBBING PROCESSES
MASS TRANSFER
SPRAY DRYING
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
DISPERSIONS
DRYING
GASEOUS WASTES
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
MIXTURES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
SCRUBBING
SOLUTIONS
SORPTION
SULFUR COMPOUNDS
SULFUR OXIDES
WASTES
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
200202 - Fossil-Fueled Power Plants- Waste Management- Noxious Gas & Particulate Emissions