Derived Types

Abstract derived type that describe the required procedure for an alpha function.

Mathias Copeman $\alpha$ function.

RKPR $\alpha$ function $$\alpha(T_r) = \left(\frac{3}{2 + T_r}\right)^k$$

Soave $\alpha$ function. $\alpha(T_r) = (1 + k (1 - \sqrt{Tr}))^2$

Abstract residual Helmholtz model.

Base model type.

Critical point

Critical point

Generic Cubic Equation of State as defined by Michelsen and Mollerup with a $\delta_1$ parameter that is not constant, and a $\delta_2$ parameter that depends on it. In the case of a two parameter EoS like PengRobinson the $\delta_1$ is the same for all components so it can be considered as a constant instead of a variable. The expression of the Equation is:

Abstract derived type that describe the required procedure for a mixing rule on a Cubic EoS

Description of a two-phase equilibria state.

Fit the binary interaction parameters of a mixtures.

This derived type holds all the relevant information for a parameter optimization problem. It keeps the base model structure that will be optimized and a procedure get_model_from_X that should reconstruct the model with the desired parameters to optimize.

$G^E$ group contribution model parameters container

Excess Gibbs energy model.

Derived type used to represent a molecule and its UNIFAC groups.

Mixing rule at zero-pressure which allows for the inclusion of an excess-gibbs model.

Nelder-Mead optimization algorithm. This is a gradient-free optimization algorithm. It is a direct search method that does not require the gradient of the objective function. The algorithm is based on the simplex method of Nelder and Mead (1965). The original source code was taken from (https://people.math.sc.edu/Burkardt/f_src/asa047/asa047.html)

Non-Random-Two-Liquid model

Wrapper derived type to optimize with the Powell method

UNIFAC $\psi(T)$ functions abstract type

Two-phase isopleth. Phase boundary line of a fluid at constant composition.

Two-phase PX envelope. Phase boundary line of a fluid at constant temperature with variation in composition.

Quadratic Mixing Rule (QMR) derived type. Classic Van der Waals mixing rules.

Set of pure components

Data structure to hold the data for the min_tpd optimization

Classic liquid-vapor UNIFAC model derived type

$$\psi_{ij}(T) = \exp(-\frac{A_{ij}}{T})$$

UNIQUAC (universal quasichemical) Excess Gibbs free energy model.