Page 8 - Handbook of Thermodynamic Diagrams 1 : Organic Compounds C1 to C4

PREFACE

Thermodynamic property data are important in many engineering applications in the chemi-
cal processing and petroleum refining industries. The objective of this book is to provide the
engineer with such data. The data are presented in thermodynamic diagrams (graphs) covering
a wide range of pressures and temperatures to enable the engineer to quickly determine values
at points of interest. The contents of the book are arranged in the following order: graphs, ref-
erences, and appendixes.

The graphs are arranged by carbon number and chemical formula to provide ease of use.
English units are used for the property values. For those involved in SI and metric usage, each
graph displays a conversion factor to provide the SI and metric units.

The graphs provide wide coverage for volume and enthalpy as a function of temperature and
pressure, including the following:

• two-phase region for saturated liquid and vapor
• superheated gas region for gases above saturation temperature
• subcooled liquid region for liquids below saturation temperature
• supercritical region for temperatures and pressures above critical point

The graphs for enthalpy also contain lines of constant entropy to permit engineering usage for
2nd law problems such as adiabatic expansion and compression of fluids.

The coverage encompasses a wide range of organic compounds including hydrocarbons,
such as alkanes, olefins, acetylenes, and cycloalkanes; oxygenates, such as alcohols, aldehydes,
ketones, acids, ethers, glycols, and anhydrides; halogenates, such as chlorinated, brominated,
fluorinated, and iodinated compounds; nitrogenates, such as nitriles, amines, cyanates, and
amides; sulfur compounds, such as mercaptans, sulfides, and sulfates; silicon compounds, such
as silanes and chlorosilanes; and many other chemical types.
The range of coverage for pressure is from 10 to 10,000 psia. Very limited experimental data
are available at pressures above 1,000 to 2,000 psia. Thus, values at the higher pressures
should be considered rough approximations. Values at lower pressures are more accurate.
The graphs are based on the Peng-Robinson equation of state (1) as improved by Stryjek and
Vera (2, 3). The equations for thermodynamic properties using the Peng-Robinson equation of
state are given in the appendix for volume, compressibility factor, fugacity coefficient, residual
enthalpy, and residual entropy. Critical constants and ideal gas heat capacities for use in the
equations are from the data compilations of DIPPR (8) and Yaws (28, 29, 30).

The literature has been carefully searched in construction of the graphs. References for
sources used in preparing the work are given in the section following the graphs near the end
of the book.

For the graphs, some of the compounds may undergo thermal decomposition (reaction) at
the higher temperatures. For such cases of thermal decomposition, the graphs are useful for
ascertaining property values of the pure compound which is contained in the reaction mixture.
Chemistry handbooks and DIPPR (8) notes may be used for specifics regarding thermal
decomposition.

VII