CPA (Cubic-Plus-Association) is an equation of state that is based on a combination of the Soave−Redlich−Kwong (SRK) equation with the association term of the Wertheim theory. The development of CPA started in 1995 as a research project funded by Shell (Amsterdam), and the model was first published in 1996. Since then, it has been successfully applied to a variety of complex phase equilibria, including mixtures containing alcohols, glycols, organic acids, water, and hydrocarbons. Focus has been placed on cases of industrial importance, e.g., systems with gas-hydrate inhibitors (methanol, glycols), glycol regeneration and gas dehydration units, oxygenate additives in gasoline, alcohol separation, etc. This manuscript, which is the first of a series of two papers, offers a review of previous applications and illustrates current focus areas related to the estimation of pure compound parameters, alcohol−hydrocarbon vapor−liquid equilibria (VLE) and solid−liquid equilibria (SLE), as well as aqueous systems. Th...

Ten Years with the CPA (Cubic-Plus-Association) Equation of State. Part 1. Pure Compounds and Self-Associating Systems

VLE predictions with the Peng–Robinson equation of state and temperature dependent kij calculated through a group contribution method

An equation of state is presented for the thermodynamic properties of propane that is valid for temperatures from the triple point temperature (85.525 K) to 650 K and for pressures up to 1000 MPa. The formulation can be used for the calculation of all thermodynamic properties, including density, heat capacity, speed of sound, energy, and saturation properties. Comparisons to available experimental data are given that establish the accuracy of calculated properties. The approximate uncertainties of properties calculated with the new equation are 0.01 % to 0.03 % in density below 350 K, 0.5 % in heat capacities, 0.03 % in the speed of sound between (260 and 420) K, and 0.02 % in vapor pressure above 180 K. Deviations in the critical region are higher for all properties except vapor pressure.

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Thermodynamic Properties of Propane. III. A Reference Equation of State for Temperatures from the Melting Line to 650 K and Pressures up to 1000 MPa

On the derivation and extension of the uniquac equation

Prediction of vapor-liquid equilibrium with the LCVM model : a linear combination of the Vidal and Michelsen mixing rules coupled with the original UNIFAC and the t-mPR equation of state

High-pressure vapour—liquid equilibrium in systems containing carbon dioxide, 1-hexene, and n-hexane

Liquid densities and excess molar volumes for water + diethylene glycolamine, and water, methanol, ethanol, 1-propanol + triethylene glycol binary systems at atmospheric pressure and temperatures in the range of 283.15-363.15 K

Vapour-liquid equilibrium data at normal pressures

Isothermal vapour–liquid equilibrium with chemical reaction in the quaternary water + methanol + acetic acid + methyl acetate system, and in five binary subsystems

Ivan Wichterle

Papers

High-pressure vapour—liquid equilibrium in systems containing carbon dioxide, 1-hexene, and n-hexane

Liquid densities and excess molar volumes for water + diethylene glycolamine, and water, methanol, ethanol, 1-propanol + triethylene glycol binary systems at atmospheric pressure and temperatures in the range of 283.15-363.15 K

Vapour-liquid equilibrium data at normal pressures

Isothermal vapour–liquid equilibrium with chemical reaction in the quaternary water + methanol + acetic acid + methyl acetate system, and in five binary subsystems

Vapour-liquid equilibria in the ethane - propane - n-butane system at high pressures