Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Separation of Protocatechuic Acid Using Di-(2-ethylhexyl)phosphoric Acid in Isobutyl Acetate, Toluene, and Petroleum Ether

Antony, Fiona Mary, Wasewar, Kailas
J. Chem. Eng. Data 2018, 63, 3, 587-597
ABSTRACT
Protocatechuic acid has potential pharmacological significances like antioxidant, antibacterial, anticancer activity etc. The extraction of carboxylic acids from dilute aqueous phase is a topic of current interest to researchers. The present equilibrium study deals with the reactive extraction of protocatechuic acid from an aqueous solution by using di-(2ethylhexyl) phosphoric acid (D2EHPA) in diluents such as isobutyl acetate (IBA), toluene, petroleum ether at isothermal conditions (2981 K). The physical extraction of protocatechuic acid with pure diluents is also carried out. The difference between the physical extraction and reactive extraction was studied. The effect of acid concentration (0.001 mol.kg-1- 0.01 mol.kg-1), extractant concentration (0.3445 mol.kg-1 -3.1010 mol.kg-1) and type of diluent on the recovery of protocatechuic acid from aqueous solution were determined. KD values were obtained in the ranges of 1.14 - 4.03, 0.12-0.67, and 0.08-0.48 for D2EHPA in isobutyl acetate, toluene, and petroleum ether respectively. A maximum KD was obtained as 4.03 using 3.101 mol.kg-1 D2EHPA (in IBA) while 80.11 % of the initial protocatechuic acid was extracted.D2EHPA-IBA system was found to provide the highest distribution coefficient of the three diluents tested. Extraction equilibrium complexation constant KE were obtained in the ranges of 5.56-1.17, 0.82-0.20, and 0.49-0.14 for D2EHPA in isobutyl acetate, toluene, and petroleum ether respectively. The feasibility of the extraction process was evaluated by calculating minimum solvent to feed ratio and number of theoretical stages of the extraction column. The number of theoretical stages for D2EHPAIBA system was calculated to be 3, and 1 for D2EHPA-toluene and D2EHPA-petroleum ether systems.
Compounds
# Formula Name
1 C7H6O4 3,4-dihydroxybenzoic acid
2 C6H12O2 2-methylpropyl ethanoate
3 C7H8 toluene
4 H2O water
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • 4
  • Molality, mol/kg - 1 ; Liquid mixture 1
  • Molality, mol/kg - 1; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • UV spectroscopy
  • 5
  • POMD
  • 1
  • 3
  • 4
  • Molality, mol/kg - 1 ; Liquid mixture 1
  • Molality, mol/kg - 1; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • UV spectroscopy
  • 5