posted on 2022-02-02, 16:12authored byAndrés
F. Arroyo-Avirama, Nicolás F. Gajardo-Parra, Valentina Espinoza-Carmona, José Matías Garrido, Christoph Held, Roberto I. Canales
An
interesting alternative to the chemically produced 2-phenylethanol
is its biotechnological synthesis. However, one of the drawbacks of
this process is that the synthesized solute is typically toxic (nonbiocompatible)
to the producing microorganism in the aqueous phase. Thus, an in situ product removal technique is recommended for separating
the product, for instance, by liquid–liquid extraction using
a hydrophobic and biocompatible solvent. First, the liquid–liquid
equilibrium between 2-phenylethanol + water was measured between 293.15
K and 323.15 K at 101.3 kPa, and modeled with PC-SAFT. Then, life
cycle analysis using CHEM21 methodology, experimental data, and the
perturbed-chain statistical associating fluid theory (PC-SAFT) were
used to evaluate the applicability of potential solvents for 2-phenylethanol
recovery from water by calculating the partition coefficient of the
solute in the solvent + water biphasic system. The solvents selected
were methyl isobutyl ketone, 2-methyl-3-buten-2-ol, 2-octanone, and
dibutyl phthalate. Thus, density and viscosity were measured for pure
2-phenylethanol, all the selected solvents, and the binary mixtures
of 2-phenylethanol and each solvent. The temperature range for all
the measurements was from 293.15 K to 333.15 K at 101.3 kPa. Excess
volumes were calculated from the density of mixtures, obtaining negative
deviations from ideality for 2-phenylethanol + 2-methyl-3-buten-2-ol,
2-phenylethanol + methyl isobutyl ketone, and 2-phenylethanol + 2-octanone
and positive deviations for 2-phenylethanol + dibutyl phthalate. The
density was modeled with PC-SAFT and the viscosity with PC-SAFT +
entropy scaling. The information on the molecular interactions between
2-phenylethanol and the extracting solvents, provided by the models
fed from the performed experiments, allows reducing the further experimental
load when designing the in situ extraction process
from a fermentation broth.