INTERACTION OF CARBON DIOXIDE WITH CARBON ADSORBENTS BELOW 400 C

Conference · Sat Jun 15 04:00:00 EDT 1963

OSTI ID:4877736

Deitz, V R; Carpenter, F G; Arnold, R G

The adsorption of carbon dioxide on carbon adsorbents (FT carbon, coconut charcoal, acid-washed bone char) and adsorbents containing basic calcium phosphate (hydroxylapatite, bone char, ash of bone char) was studied. Special consideration was given to the pretreatment of the materials. The carbons equilibrated as rapidly as the temperature; the basic calcium phosphates showed a rapid initial adsorption followed by a very slow rate which continued for days. Linear adsorption isotherms were found on FT carbon and the isosteric heats varied slightiy with coverage. The isotherms for the remaining materials had varying curvature and were for the most part in the same sequence as the estimated surface areas. The isosteric heats of carbon dioxide correlated very well with the magnitude of surface hydroxyl groups, an estimate of which was made from the chemical composition. There appeared to be three increasing levels of interaction: (1) pure physical adsorption; (2) an adsorption complex having 'bicarbonate structure'; and (3) an adsorption complex having 'carbonate structure'. (auth)

• Research Organization: National Bureau of Standards, Washington, D.C. (United States)
• NSA Number: NSA-18-001703
• OSTI ID: 4877736
• Report Number(s): CONF-73-16; AED-Conf--63-061-19
• Country of Publication: United States
• Language: English

Related Subjects

ACTIVATED CARBON
ADSORPTION
ADSORPTION ISOTHERMS
BONES
CALCIUM PHOSPHATES
CARBON
CARBON DIOXIDE
CHEMISTRY
RESIDUES