Specific Heat Measurements of Complex Saturated Hydrocarbons.

Abstract

with iodine or bromine as solutes. Therefore, one must be cautious in using these correlations meant for infinite dilution and be assured that such abnormal behavior as found in methyl alcohol-benzene is not present in the system for which diffusion coefficient is required. We would also like to point out that we have taken viscosity of solvent which is easily available, whereas Wilke and Chang have used viscosity of solution in their equation.The average percentage error remains within 13% for the proposed equation which is the same for Wilke and Chang equation. In the latter case, the diffsuion values for water as solute were not included in calculating the average because the Wilke and Chang equation does not hold good. NOMENCLATURE D = n = v, = M , = x = L, = L = DT = diffusion coefficient, sq. cm./sec. viscosity of solvent in Equation 2 and viscosity of solution molecular volume, cc./gram mole molecular weight of solvent association parameter latent heat of vaporization of solvent, at normal boiling point, cal./gram latent heat of vaporization of solute, at normal boiling point, cal./gram diffusion coefficient calculated by Equation 2in Equation 1, cp.Specific heats of complex saturated hydrocarbons were measured from 100" to 400°F.Major hydrocarbon groups investigated were cyclohexanes, bicyclohexyls, tercyclohexyls, decalins, and hydrindans. A differential heating method employing twin thermal cells was used. The cells were charged with 25 ml. of test fluid and 25 ml. reference fluid (diphenyl ether), respectively, and suspended in air in identical bronze cylinders. These cylinders were, in turn, welded in place to the circular metallic cover of a silicone fluid bath regulated to i~O . 0 2 " F . from 80 to 420°F.The samples were stirred magnetically and the rate of heating of each was followed using Chromel-Alumel thermocouples connected to a precision potentiometer. Calorimetric cell constants were previously obtained with fluids of known specific heats. The over-all accuracy of the method at two temperatures, 104" and 212"F., was determined by measuring fluids of known specific heats. Density and viscosity data obtained by standard techniques are included for each fluid.RECENTLY, greater emphasis has been placed on the physical properties of complex saturated hydrocarbons as potential fuels for supersonic aircraft and advanced missile power plants. In addition t ca density-temperature, viscositytemperature, and vapor pressure-temperature relationships, and heat of combustion, boiling range, freezing point, and thermal stability data, the heat transfer properties of these organics have been examined more closely in the past several years. It is increasingly evident that heat capacity and thermal conductivity information a t higher temperatures is of paramount importance in fully evaluating the potential of any hydrocarbon as a fuel in high performance aircraft and missile vehicles.

High-energy components of “designer gasoline and designer diesel fuel” I. Heat capacities, enthalpy increments, vapor pressures, critical properties, and derived thermodynamic functions for bicyclopentyl between the T=(10 and 600) K

“…The authors used a differential heating method with water and diphenyl ether as standards. The values reported by Gudzinowicz et al [31] are 6% to 11% lower than those of the present research. This difference is substantially larger than the 2% uncertainty claimed by the authors.…”

“…Gudzinowicz et al [31] measured heat capacities for bicyclopentyl in the liquid phase for the temperatures (313, 373, and 423) K as part of a contract for the US Air Force. The authors used a differential heating method with water and diphenyl ether as standards.…”

Thermal Conductivity of Hydrocarbon Liquid Organic Hydrogen Carrier Systems: Measurement and Prediction

“…For a comparison of the prediction model for the thermal conductivity at elevated temperatures with the experimental thermal diffusivity data, the latter were combined with temperature-dependent experimental data for the density ρ from this work fitted according to eq up to 363.15 K and for the specific heat at constant pressure c p reported in the literature for H0-DPM between 303.4 and 438.4 K and for H12-DPM between 313.15 and 483.15 K. For this, the experimental c p data were fitted by a linear equation as a function of temperature, which described all values well. For temperatures larger than those studied experimentally, the correlated data for ρ and c p represent extrapolations.…”

Bio‐Based Cycloalkanes: The Missing Link to High‐Performance Sustainable Jet Fuels

“…[211] In comparison to the parent decalin, these substituted decalins benefitted from lower freezing points, while maintaining high density and thermal stability. [212] A series of solid acid catalysts (HPW, Nafion, HY, and H-β) were examined for the dehydration/oligomerization of cyclic alcohols. While alkylated products were observed, no branched decalins were formed, indicating that these catalysts did not possess the required acidity to facilitate the rearrangement.…”

“…To efficiently obtain decalins from biomass sources, the Zou group developed an acid‐catalyzed, one‐pot process, using bio‐based cyclic alcohols (cyclohexanol, cyclopentanol) and branched cycloalkanes (methylcyclohexane, methylcyclopentane) to produce alkyl‐substituted decalins [211] . In comparison to the parent decalin, these substituted decalins benefitted from lower freezing points, while maintaining high density and thermal stability [212] …”