A modeling study of vacuum sorption characteristics of carbon dioxide on 4A zeolite molecular sieves

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6548761

Prazniak, J K; Byers, C H

A model is presented to describe the isothermal adsorption of carbon dioxide and of nitrogen on 4A zeolite molecular sieves under cryogenic conditions. Langmuir's adsorption isotherm is used to represent equilibrium concentrations at the gas-sorbent interface. Numerical solution of the partial differential model equations is accomplished using orthogonal collocation in conjunction with an ordinary differential equation integrator. Experimental results are compared with theoretical results obtained using the proposed model. Good agreement with experimental results for CO/sub 2/ cryosorption was obtained by increasing the Langmuir saturation constant to 20% greater than the value estimated in the previous study and by specifying an effective value for the mean pore radius of gas flow channels in the bed. The lack of agreement between theoretical and experimental results for N/sub 2/ cryosorption supports a conclusion reached earlier that the controlling diffusional resistance for N/sub 2/ cyrosorption is in the bed interstices and macropores.

• OSTI ID: 6548761
• Report Number(s): CONF-871113-
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION
ADSORBENTS
ADSORPTION
ADSORPTION ISOTHERMS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CRYOGENICS
CRYSTAL STRUCTURE
DIFFERENTIAL EQUATIONS
ELEMENTS
EQUATIONS
FLUID FLOW
GAS FLOW
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOTHERMS
MATERIALS
MATHEMATICAL MODELS
MICROSTRUCTURE
MINERALS
MOLECULAR SIEVES
NITROGEN
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
POROSITY
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
ZEOLITES