Application of the LBET class models to describe the structure of microporous activated carbons on the basis of argon and benzene adsorption isotherms

Abstract

The reported research is concerned with the properties of the new LBET class models designed to describe the heterogeneous adsorption on microporous carbonaceous materials. In particular, the new adsorption models were applied to a computer analysis of the microporous structure of two active carbons on the basis of argon and benzene adsorption isotherms. This paper provides for more thorough information on the properties of the proposed models and identification technique presented in the earlier papers.

Numerical analysis of the effect of the kind of activating agent and the impregnation ratio on the parameters of the microporous structure of the active carbons

“…Each cluster starts at a place (primary site) on a pore wall producing a local minimum of adhesion energy. Further molecules (the layers n > 1) are joined due to cohesive and adhesive forces [15][16][17][18][19][20][21][22][23][24]. The maximum number of layers k (referred to as the cluster size) is determined by a space preassigned to another cluster (competitive clusterization -1st type) or by a geometry of pore (2 nd type).…”

“…The second model type describes the systems in which limitations of cluster size result from pores size. Upon derivation of the LBET class models the following assumptions were taken into account [15][16][17][18][19][20][21][22][23][24]: a) the layers n > 1 are homogeneous and energetic parameters B C are the same for n > 1:…”

“…The number of primary adsorption sites is expressed by the formula given below [15][16][17][18][19][20][21][22][23][24]: where  is the geometrical parameter of the porous structure,   0, 1), m hAk is the amount of primary sites for the k th type clusters c) the first layer physical adsorption energy is expressed in the following form:…”

“…The heterogeneous adsorption model derived using the above assumptions assumes the following mathematical form, called the LBET class model [15][16][17][18][19][20][21][22][23][24]:…”

Application of the LBET class models with the original fluid state model to an analysis of single, double and triple carbon dioxide, methane and nitrogen adsorption isotherms

“…The said theory was used as a basis for the development of original LBET class analytical models, which were directly incorporated into structure identification procedures [35][36][37][38][39][40][41][42][43][44][45].…”