Solvent Screening for Separation of Lignin-Derived Molecules Using the NIST-UNIFAC Model

Abstract

Liquid–liquid phase equilibria were calculated to investigate the potential separations of value-added components from products obtained by lignin depolymerization. In this study, the ability of the group-contribution model was evaluated in the prediction of mutual solubility and liquid–liquid phase equilibria of phenolic compounds. The phase equilibria behaviors of quaternary systems were evaluated by the NIST-UNIFAC model so that the predicted results were in good agreement with the available experimental data. In sequence, the partition coefficients of 29 lignin-derived molecules with complex and polar functional groups were predicted by the model with good accuracy (RMSE = 0.7424). The abilities of binary, ternary, and quaternary solvent systems were evaluated in the counter-current chromatography (CCC) separations of the products reported in the literature that are obtained through lignin depolymerization processes. Based on the empirical solvent selection criteria for CCC measurements, promising solvent systems were found for some of the lignin products. The difficult separations of some products in other cases can be attributed to the very similar chemical structures of the monomers. Finally, it was found that the NIST-UNIFAC model could qualitatively predict the solvent systems from the Arizona series, suitable for the separation of 4-hydroxybenzoic acid, vanillin, acetovanillone, syringaldehyde, acetosyringone, vanillic acid, and syringic acid.

“Sweet space” strategy for solvent system selection in countercurrent chromatography: A case study on separation of polyunsaturated fatty acids from borage oil

“…As outlined in the introduction, established strategies for selecting solvent systems aim to identify a system that facilitates separation within a set of representative solvent systems. These strategies involve either shake flask testing [2] or utilizing predictive models (such as COSMO-RS [11,15,16], NRTL-SAC [17,18], UNIFAC [19,20], and other mathematic models [2]) to estimate the partition coefficient (K value) of a given solvent system. This raises a critical inquiry into the representativeness of these solvent systems: To what extent do these selected predetermined systems accurately reflect the diversity and complexity of CCC separations required in practice?…”

Modeling of Liquid–Vapor Phase Equilibria of Pyrolysis Bio-oils: A Review

“…b UNIFAC Fonseca et al 19 Fast pyrolysis (wheat straw) RK UNIFAC Fonseca and Funke 121 Fast pyrolysis (wheat straw) SRK-KD SRK-KD Gorensek et al 132 Lignocellulosic biomass pyrolysis PR PR Gupta et al 133 Fast pyrolysis multistep condensation Ideal gas UNIQUAC Gura 134 Fast pyrolysis of lignin RK UNIFAC-DMD Gustavsson and Nilsson 48 Flash pyrolysis of forest residues for boiler Ideal gas Wilson c Hammer et al 137 Fast Pyrolysis of equine waste for boiler Ideal gas NRTL Humbird et al 139 Custom FP reactor for pyrolysis (softwood, corn stover, switchgrass) PR-BM PR-BM Ille et al 36 Fast pyrolysis (wheat straw) Ideal gas UNIFAC-DMD Ille et al 36 Fast pyrolysis (wheat straw) GCA GCA Jasperson et al 143 LLE of model FPBO components -b UNIFAC-DMD Jalalinejad et al 118 Screening of solvents for extraction of lignols from bio-oil -b NIST-UNIFAC Kabir et al 123 Pyrolysis of municipal green waste PR-BM PR-BM Kougioumtzis et al 125 Production of 5-HMF from cellulose Ideal gas NRTL Krutof and Hawboldt 110 Distillation curve modeling for FPBO Ideal gas UNIQUAC Mohammed et al 127 Technoeconomic analysis of Napier grass pyrolysis and oil upgrading Ideal gas NRTL Mohammed et al 129 Pyrolysis of Napier grass bagasse Ideal gas NRTL Motta et al 130 Pyrolysis of different Brazilian biomasses Ideal gas NRTL Neves et al 131 Pyrolysis and hydrotreatment of sugar cane bagasse SRK-BM SRK-BM Onarheim et al 109 Fast pyrolysis of pine wood and forest residue Ideal gas UNIQUAC d Parku et al 211 Fast pyrolysis of Miscanthus and coffee grounds Ideal gas UNIFAC-DMD Peters et al 135 Fast pyrolysis of lignocellulosics (pine, eucalyptus, poplar, wheat straw) PR-BM PR-BM Shahbaz et al 136 Slow pyrolysis of cellulose, hemicellulose, and lignin PR-BM PR-BM Shemfe et al 138 Fast-pyrolysis + hydroprocessing for electrical generation (pine wood) Nothnagel EoS UNIQUAC Stephan et al 140 Ternary LLE equilibria of water, isopropyl acetate/toluene, and bio-oil surrogate -b UNIQUAC, NRTL Wagh 141 Fast pyrolysis of mallee wood Nothnagel EoS UNIQUAC d Wang et al 142 High-pressure reactive distillation of bio-oil -b NRTL Z ̌ilnik and Jazbinsěk…”

“…Pyrolysis condensates present a wide variety of compounds for which these parameters are missing, and UNIFAC variants were devised to address this problem. However, several important issues lay on the use of this method: 1. a simplification of the molecule leads to a loss of information, 2. there is no standardized method to divide the molecules into contributor groups, meaning that different users may come to different results based on the same mixture, and 3. not all possible binary combinations between groups have been experimentally determined (however, UNIFAC parameters for missing interactions can be estimated using ab initio methods , ). Some moieties may be difficult to represent using the currently estimated groups, an example being the quinones present in the work by Manrique et al The group contribution nature of UNIFAC allows for the estimation of binary interaction parameters for other activity coefficient models, like Wilson, NRTL, UNIQUAC, and SRK variants .…”

Phase Equilibrium Calculation of Bio-Oil-Related Molecules Using Predictive Thermodynamic Models

“…Because of the high cost of the experimental work, the large numbers of compounds present in FPBO, and the nature of bio-oil-related molecules (molecules with high melting points for vapor–liquid equilibrium studies), the availability of experimental phase equilibria data is limited. Therefore, thermodynamic models are an alternative to experimental research to reduce costs and save time. , Various Gibbs free energy models have been developed for phase equilibria calculations of polar and complex mixtures including correlative, predictive, and pure predictive models. Notably, the Wilson, NRTL, and UNIQUAC models are well-established correlative local composition models.…”

“…Therefore, thermodynamic models are an alternative to experimental research to reduce costs and save time. 18,19 Various Gibbs free energy models have been developed for phase equilibria calculations of polar and complex mixtures including correlative, predictive, and pure predictive models. Notably, the Wilson, 20 NRTL, 21 and UNIQUAC 22 models are well-established correlative local composition models.…”