CaO interactions in the staged combustion of coal. Fifth quarterly technical progress report, October 1, 1981-December 31, 1981

Technical Report · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5751614

Levy, A; Merryman, E L; Rising, B W

Study of the reaction of sulfur bearing compounds with CaO to form CaS was completed. A study of the oxidation of CaS is well underway and a study of kinetic and chemical parameters governing CaS and CaSO/sub 4/ formation in staged combustion, was continued. The reaction of COS with CaO exhibited a weak temperature dependence in the range studied, 1144 to 1373/sup 0/K. The reaction followed first order kinetics with respect to the unreacted calcium for both the COS-CaO and H/sub 2/S-CaO reactions. The addition of CO or H/sub 2/ to the COS or H/sub 2/S gas mixtures (to stabilize the COS or H/sub 2/S) had little or no influence on the reaction kinetics. The CaS oxidation studies indicate that the formation of CaSO/sub 4/ is slow at 1370/sup 0/K and that a significant amount of the original sulfur in the sample may have escaped, possibly as elemental sulfur or SO/sub 2/. At reaction times greater than 60 seconds, the major solid sulfur-bearing product was CaSO/sub 4/; below 60 seconds, large quantities of unreacted sulfide were evident. The results suggest that CaS oxidation to sulfate in the second stage of a two-stage combustion process may not proceed very rapidly. Results to date from the methane-coal studies show that sulfur retention in fuel-rich firings is dependent on reaction temperature and equivalence ratio. Approximately 85 percent sulfur retention is observed at postflame temperatures below 2000/sup 0/F and equivalence ratios of 1.7 to 1.9. At temperatures greater than 2000/sup 0/F, highest sulfur retention, approx. 75 percent, was observed at the lowest equivalence ratio used i.e. Phi = 1.3. These capture values were observed at short residence times, approx. 200 msec, and at a Ca/S mole ratio of 3.8.

• Research Organization: Battelle Columbus Labs., OH (USA)
• DOE Contract Number: AC22-80PC30301
• OSTI ID: 5751614
• Report Number(s): DOE/PC/30301-5; ON: DE82010299
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
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ADDITIVES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CALCIUM SULFIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL
COMBUSTION
DATA
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FUEL ADDITIVES
FUELS
INFORMATION
MATERIALS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES