A priori predictions of type I and type V isotherms by the rigid adsorbent lattice fluid

Abstract

Adsorbents exhibiting non type I adsorption behaviour are becoming increasingly more important in industrial applications, such as drying and gas separation. The ability to model these processes is essential in process optimisation and intensification, but requires an accurate description of the adsorption isotherms under a range of conditions. Here we describe how the Rigid Adsorbent Lattice Fluid is capable of a priori predictions both type I and type V adsorption behaviour in silicalite-1. The predictions are consistent with experimental observations for aliphatic (type I) and polar (type V) molecules in this hydrophobic material. Type V behaviour is related to molecular clustering and the paper discusses the model parameters governing the presence/absence of this behaviour in the predicted isotherms. It is found that both the solid porosity and the adsorbate interaction energy/energy density are deciding factors for the isotherm shape. Importantly, the model, whilst thermodynamically consistent, is macroscopic and thus computationally light and requires only a small number of physically meaningful parameters.

Assessing raw materials as potential adsorbents to remove acidic compounds from Brazilian crude oils by ESI (-) FT-ICR MS

“…The isotherms to the experimental data are shown in Figure S3, each profile was classified as a type V isotherm (Sing et al 1985). Type V isotherms are mostly given by mesoporous solids although also can be observed in microporous solids, and their adsorption behavior is determined by relatively weak adsorbent-adsorbate interactions (Nalwa 2001, Thommes et al 2005, Verbraeken & Brandani 2019. The average pore diameter (4V/A by BET) given in Figure 2 are within the mesoporous range (20Å<Dp>500Å).…”

General Cluster Sorption Isotherm

“…However, convergence is seldom achieved when the number  is greater than 5. An example By combining equation (13) and (14) one obtains…”

“…Semi-empirical approaches are reviewed Error: Reference source not found 13 and extended by a new contribution 14 . A recently proposed cluster formation modelError:…”

General Cluster Sorption Isotherm

“…Semi-empirical approaches are reviewed 3 13 and extended by a new contribution 14 . A recently proposed cluster formation model 3 stems from biochemistry.…”