The SAFT equation of state

Application areas

gSAFT brings accurate physical property calculation to many complex fluid systems for the first time.

A major advantage of the gSAFT approach is that it has an enhanced capability to incorporate general association schemes. This includes schemes 1, 2A, 2B, 3A,3B, 4A, 4B and 4C of Huang and Radosz (1990), for example:

Dimerisation (one site, such as in carboxylic acids)
Chain formation (two sites, such as in polar refrigerant molecules)
Branched chains (three sites, such as in alcohols)
Networks (four or more sites, such as in water or ammonia)
Asymmetric association (such as in HF + refrigerant mixtures or aqueous solutions of PEG)
Induced association (such as in CO₂ + MEA reacting systems).

Specific classes of system treated

gSAFT brings particular advantages to property modelling for many chemical systems of industrial interest, including the following:

Strongly associating/reacting mixtures
- Aqueous hydrogen fluoride
- Replacement refrigerants
- CO₂ absorption in monoethanolamine (MEA) solutions
Polymers
- Gas adsorption (vapour-liquid equilibria)
- Cloud curve (liquid-liquid equilibria)
- Polydisperse systems (multicomponent mixtures)
- Aqueous polymer solutions
Surfactants
- Aqueous solutions of alkyl polyoxyethylene nonionic surfactants
Hydrates
- Hydrocarbon (methane, ethane propane etc.), inert gases, CO₂, H₂S
- Mixed hydrates
- Inhibitors (methanol, glycols, salts).
Carbon dioxide and amine solvent mixtures
- CO₂ absorption in monoethanolamine (MEA), Diethanol amine (DEA), ammonia, amino-2-methylpropanol (AMP), alkyl amines (for modelling of adsorber and desorber)
Strong electrolyte solutions
- Effect of salt on vapour pressure and density of aqueous solution
- Mixed salts
- Salting out effects (e.g. hydrocarbons from aqueous solution)