Kinetics and transport effects in the dehydration of crystalline potassium carbonate hydrate

Journal Article · Thu Sep 01 00:00:00 EDT 1983 · AIChE J.; (United States)

DOI:https://doi.org/10.1002/aic.690290515· OSTI ID:6458325

Stanish, M A; Perlmutter, D D

The reaction kinetics and physical transport processes governing the thermal dehydration of solid K/sub 2/CO/sub 3/.3/2H/sub 2/O particles were investigated. Isothermal reaction rate data were gathered using a thermogravimetric balance in which narrowly-sized K/sub 2/CO/sub 3/.3/2H/sub 2/O 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 off the relevant pseudosteady-state transport equations. In the temperature range 320 to 358 K, the vacuum dehydration of K/sub 2/CO/sub 3/.3/2H/sub 2/O crystals smaller than 710 ..mu..m (-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 K/sub 2/CO/sub 3/.3/2H/sub 2/O dehydration is approximately 91 kJ/mol in vacuum; the reaction becomes extremely slow at relative pressures (P/P/sub eq/) > 0.35. 23 references, 3 figures, 8 tables.

• Research Organization: Univ. of Pennsylvania, Philadelphia
• OSTI ID: 6458325
• Journal Information: AIChE J.; (United States), Vol. 29:5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
POTASSIUM COMPOUNDS
DEHYDRATION
ACTIVATION ENERGY
CHEMICAL REACTION KINETICS
CORRELATIONS
DATA ANALYSIS
DECOMPOSITION
EXPERIMENTAL DATA
GASES
HEAT TRANSFER
HYDRATES
LOW PRESSURE
MASS TRANSFER
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
PARTICLE SIZE
PRESSURE DEPENDENCE
SOLIDS
TEMPERATURE DEPENDENCE
THERMAL GRAVIMETRIC ANALYSIS
TIME DEPENDENCE
WATER VAPOR
ALKALI METAL COMPOUNDS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
DATA
ENERGY
ENERGY TRANSFER
FLUIDS
GRAVIMETRIC ANALYSIS
INFORMATION
KINETICS
NUMERICAL DATA
QUANTITATIVE CHEMICAL ANALYSIS
REACTION KINETICS
SIZE
THERMAL ANALYSIS
VAPORS
400201* - Chemical & Physicochemical Properties