Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Influence of the aromatic ring substituents on phase equilibria of vanillins in binary systems with CO2

Skerget, M.[Mojca], Cretnik, L.[Lucija], Knez, Z.[Zeljko], Skrinjar, M.[Maja]
Fluid Phase Equilib. 2005, 231, 1, 11-19
ABSTRACT
Solid-liquid phase transitions of vanillin, ethylvanillin, o-vanillin and o-ethylvanillin in presence of compressed CO2 were determined with the modified capillary method. Furthermore, the solubilities of the above mentioned vanillins in supercritical CO2 were measured at 313.2, 333.2 and 352.2 K and in the pressure range 8-30 MPa using a static-analytic method. The expreimental equilibrium solubility data have been fitted to the Peng-Robinson equation in combination with two parameter van der Waals mixing rules and binary parameters were determined from the best fit. Results showed that the phase equilibria of vanillins in dense CO2 are influenced by the position of the hydroxyl group bound to the aromatic ring. Under the pressure of CO2 the melting point depression and also the solubility of both o-vanillins was higher that those of p-vanillins. Oppositely, the alchoxy (methoxy or ethoxy) showed no significant influence on the solubility of vanillins.
Compounds
# Formula Name
1 C8H8O3 vanillin
2 C8H8O3 2-hydroxy-3-methoxybenzaldehyde
3 C9H10O3 3-ethoxy-4-hydroxybenzaldehyde
4 C9H10O3 3-ethoxysalicylaldehyde
5 CO2 carbon dioxide
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
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Gas
  • DSC
  • 1
  • POMD
  • 1
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 2
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Gas
  • DSC
  • 1
  • POMD
  • 2
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 3
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Gas
  • DSC
  • 1
  • POMD
  • 3
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 4
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Gas
  • DSC
  • 1
  • POMD
  • 4
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • 5
  • Vapor or sublimation pressure, kPa ; Gas
  • Temperature, K; Gas
  • Gas
  • Liquid
  • Crystal - 1
  • modified capillary method
  • 36
  • POMD
  • 1
  • 5
  • Mole fraction - 1 ; Fluid (supercritical or subcritical phases)
  • Temperature, K; Fluid (supercritical or subcritical phases)
  • Pressure, kPa; Fluid (supercritical or subcritical phases)
  • Fluid (supercritical or subcritical phases)
  • Crystal - 1
  • UV spectra and CO2 gas volume
  • 34
  • POMD
  • 5
  • 2
  • Vapor or sublimation pressure, kPa ; Gas
  • Temperature, K; Gas
  • Gas
  • Liquid
  • Crystal - 2
  • modified capillary method
  • 11
  • POMD
  • 5
  • 2
  • Mole fraction - 2 ; Fluid (supercritical or subcritical phases)
  • Temperature, K; Fluid (supercritical or subcritical phases)
  • Pressure, kPa; Fluid (supercritical or subcritical phases)
  • Fluid (supercritical or subcritical phases)
  • Crystal - 2
  • UV spectra and CO2 gas volume
  • 31
  • POMD
  • 3
  • 5
  • Vapor or sublimation pressure, kPa ; Gas
  • Temperature, K; Gas
  • Gas
  • Liquid
  • Crystal - 3
  • modified capillary method
  • 29
  • POMD
  • 3
  • 5
  • Mole fraction - 3 ; Fluid (supercritical or subcritical phases)
  • Temperature, K; Fluid (supercritical or subcritical phases)
  • Pressure, kPa; Fluid (supercritical or subcritical phases)
  • Fluid (supercritical or subcritical phases)
  • Crystal - 3
  • UV spectra and CO2 gas volume
  • 27
  • POMD
  • 5
  • 4
  • Vapor or sublimation pressure, kPa ; Gas
  • Temperature, K; Gas
  • Gas
  • Liquid
  • Crystal - 4
  • modified capillary method
  • 37
  • POMD
  • 5
  • 4
  • Mole fraction - 4 ; Fluid (supercritical or subcritical phases)
  • Temperature, K; Fluid (supercritical or subcritical phases)
  • Pressure, kPa; Fluid (supercritical or subcritical phases)
  • Fluid (supercritical or subcritical phases)
  • Crystal - 4
  • UV spectra and CO2 gas volume
  • 27