Showing papers on "BET theory published in 1972"

Multilayer adsorption on heterogeneous surfaces

Abstract: Although adsorption forces are usually short range in character, multilayer adsorption also concerns the energetic heterogeneity of the adsorbing surface. In this paper we assume that each energetically homogeneous patch forming the heterogeneous surface follows the Brunauer, Emmett, and Teller (BET) adsorption isotherm, while in the submonolayer range the whole surface follows the Dubinin and Radushkevich (DR) isotherm. By so assuming we are able to obtain the multilayer adsorption isotherm for the whole heterogeneous surface, and to compare BET and DR surface areas.

A Study on Desulphurization of Flue Gases by the Active Carbon Process Using Steam Desorption (Part 3)

Abstract: Variation of properties of active carbon used in continuous run of a test plant employing the active carbon process using steam desorption was measured, and the relationship between these properties and sulphur dioxide adsorption capacity was studiedDuring the continuous run, the porous structure of active carbon developed, and the BET surface area expanded slightly The total oxygen content of active carbon also increased Thus it reached at 176wt% being over two times of that in the original active carbon after 1, 200 hours The oxygen existed mainly as surface oxides in active carbon The surface oxides were classified into basic surface group and acidic surface group for quantitative analysis The results indicated decrease in the amount of basic surface group and increase in the acidic surface groupThe sulphur dioxide adsorption capacity of active carbon did not show a relationship with its structural properties It was found that the adsorption capacity is influenced by the chemical properties of surface oxidesIt was estimated that the basic surface group functions as the activation point of chemisorption with oxidation for sulphur dioxide adsorption