The thermodynamic properties of 1,2,3,4- and 5,6,7,8-tetrahydroquinolines

Article abstract of DOI:10.1016/0021-9614(89)90100-6

Measurements leading to the calculation of the ideal-gas thermodynamic properties for 1,2,3,4- and 5,6,7,8-tetrahydroquinoline are reported.Thermochemical and thermophysical properties were determined by adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston-gauge manometry, and combustion calorimetry.Results were used to calculate standard entropies, enthalpies, and Gibbs energies of formation for the ideal-gas state at selected temperatures to 500 K.The results of the thermodynamic-property measurements were used to determine equilibrium constants, and hence, equilibrium mol alities, for the quinoline/hydrogen/tetrahydroquinoline reaction network at temperatures of interest in the processing of fossil-fuel feedstocks with a high nitrogen content.The results show that under typical processing conditions (650 K and 7.0 MPa hydrogen pressure) there is thermodynamic equilibrium between quinoline and 1,2,3,4-tetrahydroquinoline.That equilibrium conditions exist between quinoline and 5,6,7,8-tetrahydroquinoline in processing is more equivocal; however, there is strong evidence for such an equilibrium.