The kinetics of sulfation of calcium oxide. [Quarterly] project status report, June 1, 1989--August 31, 1989

Technical Report · Sun Dec 31 04:00:00 EST 1989

DOI:https://doi.org/10.2172/10167946· OSTI ID:10167946

Sarofim, A F; Longwell, J P

Studies of the sulfation rate behavior show an initial fast rate followed by a rate decrease. This behavior has generally been interpreted as product layer diffusion limitations taking over after an initial kinetic rate regime. Many investigators tried to model this observed rate change, more or less successfully. No agreement has been reached, however, as to the value of the product layer diffusivity. In this work we want to investigate the mechanism of this process. During the last quarter, most attention has been paid to analyzing the results obtained earlier. In the light of some unexpected results, we returned to the most fundamental question: what is the rate-limiting mechanism? It appeared that whatever the mechanism is, no rate ``constant`` could be used, since the rate is a function of the product layer composition, which changes during the reaction. When comparing the results obtained with different samples, however, it appeared that the best correlation was found if one assumes the limiting rate to occur at the CaSO{sub 4} interphase. This point of view has never been presented before and requires therefore a more attentive analysis.

• Research Organization: Massachusetts Inst. of Tech., Cambridge, MA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-89PC89754
• OSTI ID: 10167946
• Report Number(s): DOE/PC/89754--T5; ON: DE92018752
• Country of Publication: United States
• Language: English

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