Two-phase equilibrium in binary and ternary systems - IV. The thermodynamic properties of propane

Abstract

Existing physical and thermal data relative to propane have been summarized and correlated, and some new experimental determinations of pressure-volume-temperature relationships for the liquid at low tempera tures have been carried out to make good deficiencies in the literature.On the basis of the information thus obtained the entropy and enthalpy of propane have been calculated for conditions of temperature between -80 and 200° C, and at pressures of from 0-1 to 200 atm. The results are tabulated and also presented graphically on a temperature base. I ntr o d u ctio nRecent developments in the utilization of propane have revealed the need for more complete information as to its thermodynamic properties and, in particular, the desirability of constructing an entropy diagram covering a wide field of temperature and pressure. On examining the literature it is found th a t sufficient thermal and physical data are available to achieve this object in a serviceable manner, although the accuracy is not everywhere all th a t is to be desired.Certain entropy data, of restricted application, have already been pub lished. Thus, Dana, Jenkins, Burdick and Timm (1926) have calculated the entropy of the saturated liquid and vapour from the normal boihng-point up to c. 50° C, whilst Sage, Schaafsma and Lacey (1934) have published a more comprehensive diagram extending from 20° C up to the critical tem pera ture, with pressures ranging from 1 to about 200 atm. In both cases English units (B.Th. units, pounds per square inch, cubic feet, pounds and degrees Fahrenheit) were employed. A diagram of Ju sti (1936) appears to be identical with th a t of Sage, a centigrade scale being appended.A temperature-enthalpy chart has been published by Ragatz (1934) covering all ordinary practical conditions of temperature and pressure, but lacking in detailed information.The chief requirements, therefore, appear to be entropy and enthalpy diagrams which will correlate the work of Dana and Sage and will take into[ 280 ]on May 11, 2018 http://rspa.royalsocietypublishing.org/ Downloaded from