The influence of solvents and impurities on the separation of biobased phenol and 2-octanone

BACKGROUND: Phenol is used as a raw material in the polycarbonate industry and as the incentive for bio-based plastics and products is increasing, so is the interest in and demand for bio-based phenols. In renewable phenol production processes based on biomass, impurities derived from the biomass, including other oxygenate compounds, are expected in the phenol containing solution. Vapor–liquid equilibrium (VLE) of phenol and 2-Octanone was studied and impact of impurities thereon to gain insights applicable for similar systems in biorefineries for renewable phenol production.

RESULTS: For the binary mixture of phenol - 2-octanone azeotropic VLE behavior was found. The effects of ternary compounds on the molecular interactions between phenol and 2-octanone were studied using isothermal calorimetry (ITC) and molecular modelling (MM), and the impact on the VLE behavior was measured using an ebulliometer.

CONCLUSION: It was found that the relative volatility could be improved by adding solvents that are polar and/or contain hydrogen bond accepting groups. Ketones and ethers most strongly improved the relative volatility of the binary mixture 2-octanone – phenol. Addition of a linear alkane, a repelling component especially for 2-octanone, strongly improved the relative volatility as well. ITC and MM results, providing heat of mixing and the interaction energy of mixture components, improved fundamental understanding of the molecular interactions between phenol, 2-octanone and ternary compounds, and supported the VLE findings.