ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The reaction kinetics and physical transport processes governing the thermal dehydration of solid K2CO3·3/2H2O particles were investigated. Isothermal reaction rate data were gathered using a thermogravimetric balance in which narrowly-sized K2CO3·3/2H2O crystals were dehydrated under a water vapor atmosphere at different pressures and temperatures. The magnitudes of the heat and mass transfer resistances external to and within the solid product were estimated from solutions of the relevant pseudosteady-state transport equations. In the temperature range 320 to 358 K, the vacuum dehydration of K2CO3·3/2H2O crystals smaller than 710 μm (-25 +30 mesh) are accurately modeled by the spherical shrinking-core equation for the chemical rate control regime. In the presence of water vapor, external heat transfer to the particles was sufficient to prevent significant self-cooling; heat and mass transfer resistances within the particles were negligible. The activation energy for K2CO3·3/2H2O dehydration is approximately 91 kJ/mol in vacuum; the reaction becomes extremely slow at relative pressures (P/Peq) 〉 0.35.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690290515
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