Solubility Measurement and Modeling for the NaCl–NH₄Cl–Monoethylene Glycol–H₂O System from (278 to 353) K

Abstract

The solubilities of NH 4 Cl and NaCl in the mixtures of monoethylene glycol (MEG) and water were determined, respectively, in the temperature range of (278 to 353) K by a dynamic method. The NaCl− NH 4 Cl−MEG−H 2 O system with MEG mole fraction of 0.30 on a salt-free basis was also investigated from (278 to 353) K to determine its phase equilibrium as a function of temperature and the concentration of electrolytes. The solubilities of both NH 4 Cl and NaCl in the MEG−H 2 O mixtures were found to decrease with the addition of MEG and the increasing concentration of the secondary electrolyte. The results show that the increment of temperature causes a marked increase in the solubility of NH 4 Cl but only has a slight impact on the solubility of NaCl. The mixed-solvent electrolyte (MSE) model was applied to model solid−liquid equilibrium for the system containing NaCl, NH 4 Cl, MEG, and H 2 O. Binary interaction parameters for MEG−NH 4 + , MEG−Na + , and Na + −NH 4 + were newly determined by regressing the experimental data. The MSE model with new parameters presented very high accuracy to calculate solubilities for the NaCl−NH 4 Cl−MEG−H 2 O system. The average absolute relative deviations (AARD) between the prediction and the experimental solubility are 0.75 and 0.88% for NH 4 Cl and NaCl, respectively.

Salt Solubility and Saturated Electrical Conductivity Data for Water + Monoethylene Glycol + NaCl in a Wide Temperature Range

“…This dependence has been carefully determined, as it may be better appreciated in the zoomed region inside Figure . This NaCl solubility temperature trend is also in accordance with the measurements reported by Baldwin et al and Zeng and Li only for pure MEG. Nonetheless, this reverse behavior was not previously described for MEG aqueous mixtures.…”

“…A reverse temperature dependency of the NaCl solubility was only observed in pure MEG. 14,15,18 In all cases, it was demonstrated that the solubility of NaCl decreases considerably with MEG concentration. Djamali et al 19 measured solubility data for sodium chloride in aqueous mixtures of MEG in the temperature range of 297−467 K at 6.45 MPa.…”

“…Comparison of NaCl solubility measurements in mass fraction: this work at 293.15 K (red) and literature data ,,, at 298.15 K (black); w MEG ′ denotes the salt-free mass fraction of MEG.…”

“…In order to demonstrate the validation of the experimental procedure used, values of the observed salt solubility have been compared to the data sets of Trimble, Baldwin et al., Massoudi et al, and Zeng and Li; see Figure . Moreover, because of a weak temperature influence, values at 293.15 and 298.15 K are close.…”

“…NaCl solubility data in water are widely available in the literature. However, for MEG aqueous mixtures, NaCl solubility data are limited from room temperature up to 353 K at atmospheric pressure. − Zeng and Li reported experimental measurements for the solubility of NaCl in aqueous mixtures of MEG from T = (278 to 353) K in the whole composition range, using a dynamic and visual method. Kraus et al and Baldwin et al measured NaCl solubilities in water + MEG mixtures at 298 and 323 K, respectively.…”