Liquid−Liquid Equilibria for Phenolic Compounds, Neutral Oils, and Nitrogen Bases at 313.15 K

Abstract

Liquid−liquid extraction with triethylene glycol as solvent, water as cosolvent, and hexane as countersolvent is being investigated as a process for the separation of phenolic compounds from neutral oils and nitrogen bases. To this end, liquid−liquid equilibria at 313.15 K and atmospheric pressure have been determined for the systems triethylene glycol + hexane + water + (phenol + aniline + benzonitrile + 5-ethyl-2-methyl pyridine + mesitylene) or (m-cresol + o-tolunitrile + o-toluidine + indene + pseudocumene + undecane) or (2,4-xylenol + 3,4-xylenol + 3,5-xylenol + indane + naphthalene + dodecane). From the experimental results it is concluded that triethylene glycol, hexane, and water are effective solvents for the separation of phenolic compounds from neutral oils and nitrogen bases by means of liquid−liquid extraction. LLE binary parameters for the NRTL equation were obtained for each of the three systems by regression of the equilibrium data. The NRTL equation fit the experimental data with a root-mean-square-deviation (RMSD) of 0.0037, 0.0100, and 0.0058 for the systems containing phenol, m-cresol, and the xylenol isomers, respectively.

Liquid–Liquid Equilibrium of Water + 2-Methoxyphenol + Methyl Isobutyl Ketone and Water + 1,2-Benzenediol + Methyl Isobutyl Ketone at 303.15 K and 328.15 K

“…These runs were performed by loading the funnels with distilled water, with all other things being equal to the LLE experimental runs, and the two temperatures were found to be within ±0.1 K. During the LLE experiments, the funnels were shaken at regular intervals in order to accelerate equilibration and then left at rest to achieve phase separation, in line with the procedure reported by Venter and Nieuwoudt. 35,36 Some preliminary tests showed that 2 h was sufficient to achieve complete phase separation since clear phases were observed and stable solute concentrations in the two phases were measured. As a further confirmation, the LLE experimental results obtained for the widely studied binary system water + MIBK were found to be in good agreement with literature data, 37 as discussed in further detail in Section 3.1.…”

Solubility and Tie Line Data for Ternary System of (water + phenol + isobutyl acetate) at T=308.2 k

“…Moreover, the removal of phenol and phenolic compounds from wastewater has taken on great environmental interest over the last years [4], [5]. Therefore, recovery of phenolic compounds from aqueous solution using liquid-liquid extraction method is industrially and economically important [6].…”