Liquid-Liquid Equilibrium Measurements for Model Systems Related to Catalytic Fast Pyrolysis of Biomass

We report liquid-liquid mutual solubilities for binary aqueous mixtures involving 2-, 3-, and 4-ethylphenol, 2-, 3-, and 4-methoxyphenol, benzofuran, and 1H-indene for the temperature range (300 < T/K < 360). Measurements in the waterrich phase for (2-ethylphenol + water) and (4-ethylphenol + water) were extended to T = 440 K and T = 380 K, respectively, to facilitate comparison with literature values. Liquid-liquid equilibrium tie-line determinations were made for four ternary systems involving (water + toluene) mixed with a third component: phenol, 3-ethylphenol, 4-methoxyphenol, or 2,4-dimethylphenol. Literature values at higher temperatures are available for the three (ethylphenol + water) systems, and in general, good agreement is seen. The ternary system (water + toluene + phenol) has been studied previously with inconsistent results reported in the literature, and one report is shown to be anomalous. All systems are modeled with the predictive methods NIST-modified- UNIFAC and NIST-COSMO-SAC, with generally good success (i.e., within 0.05 mole fraction) in the temperature range of interest (300 < T/K < 360). This work is part of a larger project on the testing and development of predictive phase equilibrium models for compound types occurring in catalytic fast pyrolysis of biomass, and background information for that project is provided.