Adsorption Isotherm Analyzer

Fit Henry, Langmuir, dual-site Langmuir, Toth, and Sips models to gas–solid adsorption isotherms, with parameter standard errors and the best model chosen by AICc. Nitrogen, argon, krypton, and CO₂ isotherms at their standard temperatures give BET (Rouquerol range) and Langmuir surface areas, and isotherms at two or more temperatures give Clausius–Clapeyron isosteric heats. Ideal adsorbed solution theory predicts mixture uptakes and selectivities, and materials can be ranked by working capacity, selectivity, BET area, or Henry constant.
0 data rows in 0 isotherms ready
Estimated minimum cost: $—

Examples

Isotherm data

One row per point with material_id, adsorbate, temperature, loading, and either pressure (absolute, in the pressure unit above) or relative_pressure (p/p0). Each material, adsorbate, and temperature forms one isotherm with at least three pressures. Adsorbates are matched to known gases by name or formula (for example nitrogen or N2). An optional branch column marks desorption points, which are not fitted.

or drop a file here

Models and characterization

Each selected model is fitted to every isotherm with parameter standard errors; the lowest AICc fit is marked best. A model needs at least two more pressures than it has parameters (Henry 1, Langmuir 2, Toth and Sips 3, dual-site Langmuir 4).

Isotherm models

Mixture prediction (IAST)

Ideal adsorbed solution theory combines each material's pure-component fits at one temperature to predict adsorbed-phase composition and uptakes for a gas mixture of 2 to 5 components. Every component needs an absolute-pressure isotherm at that temperature; points beyond the measured pressures are flagged as extrapolated.

Material ranking

Rank every material by up to four criteria, highest first. Materials without the data a criterion needs are listed as ineligible with the reason.