Monoethylene
glycol (MEG) is a gas hydrate inhibitor widely applied
for natural gas flow assurance. A series of density and electrical
conductivity measurements of water + MEG + NaCl mixtures are reported,
allowing the supervision of the MEG regeneration unit. Density (509
data points) and electrical conductivity (212 data points) measurements
were performed in wide ranges of temperature, T =
278.15–363.15 K, and concentration of solvents and NaCl up
to almost saturation. The theory of solutions was applied for density
description using excess volume, which was correlated with the Redlich–Kister
equation. The resulting absolute and relative mean deviations are
0.00127 g·cm–3 and 0.12%, indicating accurate
representation. A semiempirical correlation with 15 adjustable parameters
was considered for electrical conductivity of water + MEG + NaCl mixtures.
The obtained absolute and relative mean deviations are 1.49 mS·cm–1 and 5.70%. The properties functions presented an
approximately orthogonal behavior to each other, allowing the determination
of mixture composition from experimental density and electrical conductivity
data. The Matlab environment was found to be robust in solving the
nonlinear system of two equations with constraints. The proposed methodology
was extensively tested, and deviations less than 0.0060 and 0.0011
in solvents and NaCl mass fractions were obtained, respectively, demonstrating
the required accuracy for industrial application.