Heterogeneous gas-solid reaction studies in a high temperature diffusion cell: the effect of sodium-chloride on sulfur capture in fluidized bed combustion

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5923577

Bardakci, T

The single pellet high temperature diffusion cell reactor was designed and constructed to measure the effective diffusivity of argon and nitrogen through the porous limestone matrix during calcination, sintering and sulfation reactions. The results reveal that the following equation can be used to estimate the effective diffusivity of argon through calcined Greer limestone as a function of temperature (775 to 1000/sup 0/C) and calcination time. D/sub Ar/ = 62.3 e/sup -14600/RT/ + 113.6 theta e/sup -29400/RT/ where D/sub Ar/ is the effective diffusivity of argon in cm/sup 2//sec, T is the absolute temperature in /sup 0/K, and theta is the calcination time in hours. The diffusivity of argon was determined during the sulfation reaction of calcined Greer limestone with an SO/sub 2//O/sub 2/ gas mixture. The conversion of calcined Greer limestone to calcium sulfate was determined by material balance. Even after complete sulfation of surface layer, exposure to salt vapor increased the size of the pores. The diffusivity of gases through the porous structure and the saturation reaction conversion increased with NaCl vapor addition. The conversion increased by a factor of 3.26 at 943/sup 0/C and 3.16 at 841/sup 0/C. A range of 43% to 49% conversion was obtained at the surface layer between 840/sup 0/C and 943/sup 0/C. NaCl vapor exposure resulted in insignificant change in the reaction extent at 756/sup 0/C, with a saturation conversion of 28%.

• OSTI ID: 5923577
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000 -- Coal
Lignite
& Peat-- Combustion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ARGON
CALCINATION
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE ROCKS
CARBONATES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COMBUSTION
CONSTRUCTION
DECOMPOSITION
DESIGN
DIFFUSION
ELEMENTS
EQUATIONS
FABRICATION
FLUIDIZED-BED COMBUSTION
FLUIDS
GASES
HALIDES
HALOGEN COMPOUNDS
LIMESTONE
MATHEMATICS
NONMETALS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PELLETS
POROSITY
PYROLYSIS
RARE GASES
REACTORS
ROCKS
SEDIMENTARY ROCKS
SINTERING
SODIUM CHLORIDES
SODIUM COMPOUNDS
SULFIDATION
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE
VERY HIGH TEMPERATURE