Separation of phenolic compounds from oil mixtures by betaine‐based deep eutectic solvents

Abstract

Separation of phenolic compounds from coal tar is of both economic and technological interest in the processing of coal tar. In this work, three deep eutectic solvents (DES) of betaine-glycerol, betaine-DL-lactic acid, and betaine-levulinic acid were formed and used to extract phenolic compounds from model coal tar. The effects of extraction time, temperature, initial phenol content, and mass ratio of DES to phenol on extraction were investigated. Then, the extraction and formation mechanisms of extractant were studied by the experimental and simulation methods. In addition, the neutral oil entrainment and the recycling of DES were also investigated. The results showed that phenol could be efficiently extracted in short time by three DES and the temperature had little effect on phenol extraction. Fourier transform infrared spectroscopy and deformation charge density indicated that the three DES are formed with hydrogen bonding interaction, the hydrogen bond acceptor and hydrogen bond donor of DES can form hydrogen bonding with phenol, respectively, and then synergistic extract phenol from model oil. The betaine-glycerol (Bet-Gly) was determined to be the preferable solvent with the extraction efficiency of 94.6% and 5.2% neutral oil entrainment under optimal conditions. It is an advantageous extractant in the separation of phenolic compounds from coal tar.

Computer Simulations of Deep Eutectic Solvents: Challenges, Solutions, and Perspectives

“…DFT approaches have not only been fruitful for studies of distribution patterns of DES components, but also in studies of interactions of DESs with various functional substances in gas separation. In particular, free energy changes and structural analyses have been used to develop new solutions towards desulfurization of liquid fuels [ 73 , 78 , 85 , 86 , 89 ], capturing greenhouse gases such as CO 2 or SO 2 [ 72 , 79 , 90 , 91 ], metronidazole extraction from plasma [ 92 ], developing efficient mercury removal strategies from different gases [ 93 ], extractive detoxification of feedstocks for the production of biofuels using new hydrophobic DESs [ 74 ], capturing NH 3 [ 94 ], and for separating phenolic compounds from oil mixtures [ 95 ].…”

Computer Simulations of Deep Eutectic Solvents. Challenges, Solutions, and Perspectives

“…DFT approaches have not only been fruitful for studies of distribution patterns of DES components, but also in studies of interactions of DESs with various functional substances in gas separation. In particular, free energy changes and structural analyses have been used to develop new solutions towards desulfurization of liquid fuels [56,61,68,69,72], capturing greenhouse gases such as CO2 or SO2 [55,62,73,74], metronidazole extraction from plasma [75], developing efficient mercury removal strategies from different gases [76], extractive detoxification of feedstocks for the production of biofuels using new hydrophobic DESs [57], capturing NH3 [77] and for separating phenolic compounds from oil mixtures [78].…”

Screening of Double Solvents Based on Multi-Index Evaluation Method for the Selective Separation m-Cresol from Model Oil

“…Low-temperature coal tar (LTCT) contains a large number of phenolic compounds and aromatic hydrocarbons. 1 − 3 Phenolic compounds are important chemical raw materials and the separation of phenolic compounds in LTCT has a beneficial effect on subsequent oil processing. 4 − 6 In recent years, ionic liquids (ILs) are widely reported to use phenol separation from LTCT and model oil mixtures.…”

“…Low-temperature coal tar (LTCT) contains a large number of phenolic compounds and aromatic hydrocarbons. − Phenolic compounds are important chemical raw materials and the separation of phenolic compounds in LTCT has a beneficial effect on subsequent oil processing. − In recent years, ionic liquids (ILs) are widely reported to use phenol separation from LTCT and model oil mixtures. , For example, Hou et al used 1-butyl-3-methyl imidazolium chloride ([C 4 mim]­[Cl]) to extract phenol from hexane and the extraction efficiency was up to 99.1% . Then, some ILs with low viscosity and without corrosive halogen ions were designed to separate phenolic compounds, such as 1-ethyl-3-methyl imidazolium thiocyanate ([C 2 mim]­[SCN]), 1-ethyl-3-methyl imidazolium lactate ([C 2 mim]­[LAC]), and tetraethylammonium amino acid (TAAA) ILs …”