VLE Parameter Regression

Fit binary NRTL interaction parameters (τᵢⱼ = aᵢⱼ + bᵢⱼ/T, α) to measured Txy or Pxy vapor–liquid equilibrium data by least squares on bubble points, for use in VLE / Flash in place of tabulated or missing pairs.
0 data points ready
Estimated minimum cost: $—

Examples

Binary pair

Identify the two species by name or SMILES. Vapor pressures and liquid volumes come from the thermo property database; criticals set the cubic equation of state for the vapor.

ComponentIdentifierName or SMILESTc (K)Pc (Pa)ω
1
2

VLE data

One row per measured bubble point: temperature_k, pressure_pa, and liquid mole fraction x1 of component 1, with vapor mole fraction y1 when measured. Units are SI (K, Pa) — temperatures in °C will not fit. CSV or a JSON array of objects, up to 200 points.

or drop a file here
0 / 200 points

Fit settings

Least-squares fit of binary NRTL parameters against bubble points computed with the same gamma–phi model as VLE / Flash, so the fitted parameters can be used there directly.

Fit parameters
Starting values▶