Hysteresis-dependent adsorption-desorption cycles: Generalization for isothermal conditions

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690400602· OSTI ID:7008014

Rajniak, P; Yang, R T ^[1]

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1. State Univ. of New York, Buffalo, NY (United States). Dept. of Chemical Engineering

Hysteresis-dependent adsorption-desorption equilibrium cycles are measured for the systems water vapor-silica gel at 25 C. Various and distinct types of equilibrium cycles are observed, depending on the relative positions of the limiting partial pressures with respect to the closure points of the main hysteresis loop as well as the history of the cycle. Hysteresis-dependent cycles are classified accordingly. The simple theoretical model based on the network pore blocking theory for predicting primary and secondary adsorption and desorption isotherms is extended for predicting isotherms of higher orders and equilibrium cycles of all types. Only primary adsorption and desorption isotherms are needed for the predictions. Furthermore, there exists an infinite number of equilibrium cycles between any to partial pressures within the main hysteresis loop; the exact path of the cycle depends on the history before the cycle is initiated -- it is memory-dependent.

• OSTI ID: 7008014
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 40:6; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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ADSORBENTS
ADSORPTION
ADSORPTION ISOTHERMS
DESORPTION
DRYING
FLUIDS
GASES
HYSTERESIS
ISOTHERMS
PHYSICAL PROPERTIES
SEPARATION PROCESSES
SILICA GEL
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
VAPORS
WATER VAPOR