TY - JOUR
T1 - Extensive Study of the Capabilities and Limitations of the CPA and sPC-SAFT Equations of State in Modeling a Wide Range of Acetic Acid Properties
AU - Ribeiro, Rafael T. C. S.
AU - Alberton, André L.
AU - Paredes, Márcio L. L.
AU - Kontogeorgis, Georgios M.
AU - Liang, Xiaodong
PY - 2018
Y1 - 2018
N2 - The accurate description of many
thermodynamic properties of acetic
acid and its mixtures can be a challenge to model with standard thermodynamic
models such as local-composition activity coefficient models and cubic
equations of state. A possible solution is offered by association
equations of state, e.g., those belonging to the statistical associating
fluid theory (SAFT) family. While several researchers have studied
the use of SAFT variants to model acetic acid properties (pure compound
and mixtures), with few exceptions, those studies focused exclusively
on phase equilibria including vapor pressure and density. Other important
properties, such as the speed of sound, second virial coefficient,
compressibility factor, enthalpy of vaporization, and isobaric heat
capacity have not been considered yet. Few studies investigate which
is the appropriate association scheme to be used for acetic acid.
In this work, we compare the capabilities of two association models,
cubic plus association (CPA) and simplified perturbed-chain SAFT (sPC-SAFT),
to predict a wide range of properties of acetic acid (mixtures) including
derivative properties. We evaluate the influence of including one
or more of those properties in the parameter estimation procedure
for sPC-SAFT, we compare the results obtained with various choices
of the association schemes (one or two sites), and finally we evaluate
the performance of CPA and sPC-SAFT on correlating the phase equilibria
of the binary mixtures of acetic acid with water, hexane, or ethanol.
It is concluded that both equations of state perform overall similarly,
with the one-site scheme performing better overall, especially for
some properties. The results of the evaluation also show that some
properties are intercorrelated in the parameter estimation process,
making it essentially impossible to obtain sets that can accurately
describe all the properties of acetic acid.
AB - The accurate description of many
thermodynamic properties of acetic
acid and its mixtures can be a challenge to model with standard thermodynamic
models such as local-composition activity coefficient models and cubic
equations of state. A possible solution is offered by association
equations of state, e.g., those belonging to the statistical associating
fluid theory (SAFT) family. While several researchers have studied
the use of SAFT variants to model acetic acid properties (pure compound
and mixtures), with few exceptions, those studies focused exclusively
on phase equilibria including vapor pressure and density. Other important
properties, such as the speed of sound, second virial coefficient,
compressibility factor, enthalpy of vaporization, and isobaric heat
capacity have not been considered yet. Few studies investigate which
is the appropriate association scheme to be used for acetic acid.
In this work, we compare the capabilities of two association models,
cubic plus association (CPA) and simplified perturbed-chain SAFT (sPC-SAFT),
to predict a wide range of properties of acetic acid (mixtures) including
derivative properties. We evaluate the influence of including one
or more of those properties in the parameter estimation procedure
for sPC-SAFT, we compare the results obtained with various choices
of the association schemes (one or two sites), and finally we evaluate
the performance of CPA and sPC-SAFT on correlating the phase equilibria
of the binary mixtures of acetic acid with water, hexane, or ethanol.
It is concluded that both equations of state perform overall similarly,
with the one-site scheme performing better overall, especially for
some properties. The results of the evaluation also show that some
properties are intercorrelated in the parameter estimation process,
making it essentially impossible to obtain sets that can accurately
describe all the properties of acetic acid.
U2 - 10.1021/acs.iecr.8b00148
DO - 10.1021/acs.iecr.8b00148
M3 - Journal article
VL - 57
SP - 5690
EP - 5704
JO - Industrial & Engineering Chemistry Research
JF - Industrial & Engineering Chemistry Research
SN - 0888-5885
IS - 16
ER -