Gilles Richner - Temperature oscillation calorimetry for the determination of the heat capacity in a small-scale reactor

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      Publication Details (including relevant citation   information):

      Chemical Engineering Science, 2008,   36, 3755 - 3765


      This contribution describes a method for heat capacity   determination in a small-scale reaction calorimeter under   quasi-isothermal conditions. The heat capacity of the reactor   content is calculated from the amplitudes and the phase shifts of   the reactor temperature, of the electrical heater and of the   cooling rate when forced temperature oscillations are applied.   The heat capacities of eight solvents (water, ethanol, methanol,   acetone, 1-octanol, diethylenglycol, toluene, and 1-butanol)   covering a wide range of viscosity were calculated for various   experimental conditions, including reactor volume and stirrer   speed. Systematic deviations were detected when compared to the   corresponding literature values. Straight line calibration with   the total heat transfer coefficient and two modern multivariate   calibration techniques (partial least squares and neural network)   were applied to correct for these deviations. The different   calibrations show similar precision and allow for an online   determination of the heat capacity with an accuracy comparable to   other published methods. Successful applications include the   determination of the heat capacities for n-heptane, for various   homogenous ethanol/water mixtures, and during the course of the   hydrolysis of concentrated sulfuric acid.

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