Adsorption and deformation phenomena at interaction of N2 and microporous carbon adsorbent

Abstract

Deformation of activated carbon adsorbent ACC (adsorbent obtained by removing Si from SiC) upon N(2) adsorption has been studied. To solve this problem, a dilatometer was used. Its main part was a line differential transformer, the core of which was connected to the adsorbent by means of a rod. Any changes in the adsorbent height caused a change in the core position in the transformer, which influenced the signal recorded from its secondary winding. These results were compared with the adsorption isotherms. High sensitivity of the dilatometric method has been shown. The dilatometer used allowed the measurement of absolute deformations in the range 1 x 10(-4) to 3 mm.

Adsorption of Gases, Vapors and Liquids by Microporous Adsorbents

“…The net result would be expansion of the solid. Analogous results were obtained for adsorption of CO 2 and Ar on the same adsorbent (Yakovlev et al, 2003). The same behavior of deformation curves in the case of zeolites can be ascribed to displacement of cations caused by the specific interaction with adsorbed molecules.…”

“…In general case, however, the dependencies of adsorption deformation on the amount adsorbed and temperature are more complicated. Figure 6 gives results of deformation of microporous carbons induced by adsorption of nitrogen as a function of the amount of nitrogen adsorbed at different temperatures (Yakovlev et al, 2003). Figure 6 implies that the curves describing deformation of the ACC activated carbon induced by adsorption of nitrogen show the region of compression at relatively low temperatures (243-293 K).…”

Highly selective CO2 capture by S-doped microporous carbon materials

“…Current research efforts are focused on increasing the interaction between the adsorbent and CO 2 which can be achieved by increasing the surface area, as well as modifying the surface and pore structure [48][49][50][51][52]. Fig S9a shows that the a-SG6 sample exhibits the largest micropore volume at 0.6 nm pore size, when compared to other samples.…”

The role of adsorption compression in nanocapillarity

“…These internal forces were noticed in experiments with ceramic nanoparticles [32,33]. Systematic experimental studies of such forces were performed by high-precision measurements of expansion of various nanoporous solids loaded with fluid adsorbates [34][35][36][37][38]. These include nanoporous glass [34], zeolites [35], nanosilicates [36] and activated carbons [37].…”

“…5 and 6 illustrate that oscillatory adhesion forces [39,43] and phenomenon of adsorption compression [13][14][15][16][17] have the same thermodynamic origin. Note that adsorption compression results in significant internal forces when various fluid molecules are adsorbed in pores of solids [32][33][34][35][36][37][38]. These forces have the same nature as oscillatory adhesion forces; the difference is that there is a distribution of pore sizes and oscillations are averaged.…”