Thermodynamics of hydrocarbon

D. R. StuU and co-workers. Chemical Thermodynamics of Hydrocarbon Compounds,]olm Wiley Sons, Inc., New York, 1969, p. 368. 

Selected Values of Physical and Thermodynamics of Hydrocarbon and Related Compounds, American Petroleum Institute Research Project 44, Texas A M University,... 

Firoozabadi, a. 1999. Thermodynamics of Hydrocarbon Reservoirs. McGraw-Hill, New York. 

By now an extensive experience has been accumulated in using of methanol in gas industry. The big volume of field and laboratory experiments together with theoretical works on thermodynamics of hydrocarbon systems have allowed to elucidate the influence of an inhibitor on the natural gas-water system [61, GIGS]. 

Simha, R., and Yahsi, U., Statistical thermodynamic of hydrocarbon fluids scaling parameters and their group contributions, J. Chem. Soc. Faraday Trans., 91, 707-715 (1995). 

Scott and McCullough s review of the thermodynamics of hydrocarbons and sulphur compounds includes lists of the following properties free energy function , enthalpy function , enthalpy, entropy, heat capacity, enthalpy of formation, free energy of formation, and logarithm of equilibrium constant of formation at temperatures 0, 273.16, 298.16, 300, 400, 500, 600, 700, 800, 900, and 1000 K. 

Now let us consider the non-electrolytes. Here we have two very distinct types of behaviour. There are the so-called hydro-phobic, and the hydrophilic effects. The hydrophobic effect can be shown schematically from a consideration of the thermodynamics of hydrocarbon solutions. Usually a non-ideal solution arises because the two components either strongly attract each other or strongly repel each other the effects are shown in the enthalpy. Figure 8 shows various types of behaviour, as reflected in the excess thermodynamic functions (Rowlinson, 1969). The drawn out lines are free energies, the broken lines are enthalpies and the dotted lines are the entropy curves. A positive free energy means a positive deviation from ideal behaviour. In normal systems AG follows the AH curve fairly benzene-MeOH. In... 

Zwolinski, B. J., and R. C. Wilhoit "Vapor Pressures and Heats of Vaporization of Hydrocarbons and Related Compounds," Thermodynamic Research Center, Dept, of Chemistry, Texas A M University, College Station, Texas, 1971. 

Example of NHV calculation for toluene based on thermodynamic data from Thermodynamic Tables - Hydrocarbons" edited by TRC (Thermodynamic Research Center, The Texas A M University System College Station, Texas, USA). 

Ideal Adsorbed Solution Theory. Perhaps the most successful approach to the prediction of multicomponent equiUbria from single-component isotherm data is ideal adsorbed solution theory (14). In essence, the theory is based on the assumption that the adsorbed phase is thermodynamically ideal in the sense that the equiUbrium pressure for each component is simply the product of its mole fraction in the adsorbed phase and the equihbrium pressure for the pure component at the same spreadingpressure. The theoretical basis for this assumption and the details of the calculations required to predict the mixture isotherm are given in standard texts on adsorption (7) as well as in the original paper (14). Whereas the theory has been shown to work well for several systems, notably for mixtures of hydrocarbons on carbon adsorbents, there are a number of systems which do not obey this model. Azeotrope formation and selectivity reversal, which are observed quite commonly in real systems, ate not consistent with an ideal adsorbed... 

TRC Thermodynamic Tables—Hydrocarbons and TRC Thermodynamic Tables—Honhydrocarbons, serial pubbcations of the Thermodynamic Research Center, Texas A M University System, CoUege Station, Tex. 

G. Egloff, G. HuUa, and V. I. Komarewski, Isomerisation of Pure Hydrocarbons, Reinhold Publishing Corp., New York, 1942 D. R. Stuhl, E. E. Westrum, and G. C. Sinke, The Chemical Thermodynamics of Organic Compounds, ]ohn Wiley Sons, Inc., New York, 1969. 

Selected Properties of Hydrocarbons and Pelated Compounds American Petroleum Institute Project 44, Chemical Thermodynamic Properties Center, Dept, of Chemistry, A M College of Texas, College Station, Tex. 

Compiled from Daubert, T. E., R. R Danner, H. M. Sibul, and C. C. Stebbins, DIPPR Data Compilation of Pure Compound Properties, Project 801 Sponsor Release, July, 1993, Design Institute for Physical Property Data, AlChE, New York, NY and from Thermodynamics Research Center, Selected Values of Properties of Hydrocarbons and Related Compounds, Thermodynamics Research Center Hydrocarbon Project, Texas A M University, College Station, Texas (extant 1994). 

Selected Values of Properties of Hydrocarbons and Related Compounds, Vol. 7, TRC Tables (u-y). Thermodynamic Research Center, Texas A M Univ., College Station, Texas, 1977 and 1987. 

If the thermodynamic data for a compound of interest have not been determined and abulated, it may be possible to estimate AHf or AGj from tabulated data pertaining to dividual structural units. Procedures have been developed for estimating thermodynamic characteristics of hydrocarbons and derivatives by summing the contributions of the constituent groups. The group increments are derived from experimental thermochemical iata and therefore depend on the existence of reliable data for the class of compounds of merest. 

In the discussion of the relative acidity of carboxylic acids in Chapter 1, the thermodynamic acidity, expressed as the acid dissociation constant, was taken as the measure of acidity. It is straightforward to determine dissociation constants of such adds in aqueous solution by measurement of the titration curve with a pH-sensitive electrode (pH meter). Determination of the acidity of carbon acids is more difficult. Because most are very weak acids, very strong bases are required to cause deprotonation. Water and alcohols are far more acidic than most hydrocarbons and are unsuitable solvents for generation of hydrocarbon anions. Any strong base will deprotonate the solvent rather than the hydrocarbon. For synthetic purposes, aprotic solvents such as ether, tetrahydrofuran (THF), and dimethoxyethane (DME) are used, but for equilibrium measurements solvents that promote dissociation of ion pairs and ion clusters are preferred. Weakly acidic solvents such as DMSO and cyclohexylamine are used in the preparation of strongly basic carbanions. The high polarity and cation-solvating ability of DMSO facilitate dissociation... 

It has been found that there is often a correlation between the rate of deprotonation (kinetic acidity) and the thermodynamic stability of the carbanion (thermodynamic acidity). Because of this relationship, kinetic measurements can be used to construct orders of hydrocarbon acidities. These kinetic measurements have the advantage of not requiring the presence of a measurable concentration of the carbanion at any time instead, the relative ease of carbanion formation is judged from the rate at which exchange occurs. This method is therefore applicable to very weak acids, for which no suitable base will generate a measurable carbanion concentration. 

The following table gives exchange rates in methanolic sodium methoxide for a number of hydrocarbons and equilibrium acidities for some. Determine whether there is a correlation between kinetic and thermodynamic acidity in this series of compounds. If so, predict the thermodynamic acidity of the hydrocarbons for which no values are listed. 

Edmister, W, G., Application of Thermodynamics to Hydrocarbon Processing, Pet. Refiner, Part XVI, Effect of Pressure on Entropy and Enthalpy, Feb. (1949). 

Rossini, F. D., Pitzer, K. S., Arnett, R. L., Braun, R. M., and Pimentel, G. C., Selected Values of Physical and Thermodynamic Properties of Hydrocarbons and Related Compounds. Carnegie Press, Pittsburgh, Pennsylvania, 1953. 

For values of heats of combustion of large numbers of organic compounds hydrocarbons and others, see Cox, J.D. Pilcher, G. Thermochemistry of Organic and Organometallic Compounds, Academic Press NY, 1970 Domalski, E.S. J. Phys. Chem. Ref. Data, 1972,1, 221. For large numbers of heats of formation values (from which heats of combustion are easily calculated) see Stull, D.R. Westrum Jr., E.F. Sinke, G.C. The Chemical Thermodynamics of Organic Compounds, Wiley NY, 1969. 

A different approach to the problem of hydrocarbon acidity, and hence carbanion stability, is that of Shatenshtein and Shapiro, who treated hydrocarbons with deuterated potassium amide and measured the rates of hydrogen exchange. The experiments did not measure thermodynamic acidity, since rates were measured, not positions of equilibria. They measured kinetic acidity, that is, which compounds... 

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