In chromatographic separations involving elutes with large differences in the molecular size, the adsorption saturation capacities of the elutes may differ because of the differences in the degree of size exclusion. With uneven saturation capacities, isotherm crossovers may occur, which often results in selectivity reversal. In this work, a new multicomponent isotherm has been developed for thi...

Separation of nitrogen from a gaseous mixture is required for many industrial processes. In this study, the adsorption of nitrogen on zeolite 4A was investigated in terms of different adsorption isotherm models and kinetics. An increase in the initial pressure from 1 to 9 bar increases the amount of adsorbed nitrogen from 6.730 to 376.030 mg/(g adsorbent). The amount of adsorbed nitrogen increa...

A favorable isotherm open to the right to some extent is better than a linear isotherm to give shorter column height in pressure swing adsorption(PSA). We face to a problem how favorable isotherm is actually favorable in PSA operation. The purpose of this paper is to propose how to construct such a custom made isotherm which optimizes the PSA processes. The PSA mod...

In this study, modeling of hydrogen, nitrogen, carbon monoxide, methane and carbon dioxide sorption on UTSA-16 framework extrudates in the pressure swing adsorption process was carried out. The pure gas adsorption of these gases at the pressure range (0 to 80) bars at (298, 313, and 338) K have also been measured in a fixed bed. Langmuir, Toth, Sips, UNILAN, Virial and Dubinin-Astakhov adsorpti...

We study the nucleation of a bubble in a metastable Lennard-Jones (LJ) fluid, confined to a spherical pore with wetting walls, by a combination of grand canonical, canonical ensemble, and gauge cell Monte Carlo simulation methods complemented by the Voronoi-Delaunay tessellation analysis of statistical geometry of intermolecular cavities. We construct the isotherm of confined fluid in the form ...

Comparison analysis of linear least-square method and non-linear method of three widely used isotherms (Langmuir, Freundlich, and Redlich-Peterson) were examined to experiment with Remazol Red (C.I. 18221) onto pistachio nut shells at a solution temperature of 293 K. All three isotherm equations showed a better fit to the experimental equilibrium data. The results show that the Langmuir model s...

The sorption isotherm is important information for evaluating the ability of an adsorption system to treat the industrial waste water. In this study, eleven datasets from literatures were selected and three two-parameter and threeparameter equations were used to evaluate adsorption systems. Quantitative criteria included six error functions, and the quantitative criterion was residual plots. Is...

Analytical isotherm equations such as Langmuir and Freundlich isotherms are widely used for modeling adsorption data. However, these isotherms are primarily useful for simulating data collected at a fixed pH value and cannot be easily adapted to simulate pH-dependent adsorption effects. Therefore, most adsorption studies currently use numerical surface-complexation models (SCMs), which are more...

Water availability is the most influential factor affecting plant carbon (δ(13)C) and nitrogen (δ(15)N) isotope composition in arid and semi-arid environments. However, there are potential differences among locations and/or species in the sensitivity of plant δ(13)C and δ(15)N to variation in precipitation, which are important for using stable isotope signatures to extract paleo-vegetation and ...

Using square wave voltammetry, we show an increase in the electrochemical detection of trinitrotoluene (TNT) with a working electrode constructed from plasma modified graphene on a SiC surface vs. unmodified graphene. The graphene surface was chemically modified using electron beam generated plasmas produced in oxygen or nitrogen containing backgrounds to introduce oxygen or nitrogen moieties. ...