Implementation and test of the implicit version of the CPA-EoS (Igben et. al., Fluid Phase Equilibria, 2026)

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The implicit version of CPA was implemented based on the paper by Igben.

A report has been generated to document and test the implementation of the implicit algorithm:

[EvenSol]

Here is further work to improve the computational speed of equations of state with association models.

Structure-Exploiting Acceleration of CPA Equation of State Solvers Quasi-Newton Updates Anderson Mixing, and Site Symmetry Reduction
Structure-Exploiting Acceleration of CPA Equation of State Solvers Quasi-Newton Updates Anderson Mixing, and Site Symmetry Reduction.pdf

[EvenSol]

A discussion of how to do Site Symmetry Reduction for association models.
Site Type Reduction in Wertheim Association Models Exact2.pdf

[EvenSol]

In the following work it is demonstrated how the new numerical methods are able to speed up a full TEG dehydration process calculation:
Speed and Robustness of CPA Equation of State Solvers in.pdf

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Some discussion in this document:
https://github.com/equinor/neqsim/blob/master/neqsim-paperlab/books/the_cubic_plus_association_equation_of_state_2026/submission/book.pdf