The Compressibility of and an Equation of State for Gaseous Normal Butane

Abstract

Ill 26 (0 to 130°) are somewhat higher than the values given in Table I.Critical Constants.-In Table II are given the compressibility data in the critical region, and these values are plotted in Fig. 1. The pressures are given to 0.0005 atm. since relative values are consistent to about 0.001 atm. The critical data resulting from our measurements are given at the bottom of Table II. Germann and Pickering7 select íQ = 153°, pc = 36 atm., which are the values obtained by Seibert and Burrell.6 The critical isotherm, 152.01°, was reinvestigated with the second loading of the bomb. The pressures so measured were uniformly 0.02

Thermophysical properties of normal butane from 135 to 700 K at pressures to 70 MPa

“…The temperature {J^= 272.638 K) is froin vapor pressure eq (2) at a pressure of 1 atm = 0.101325 MPa. Liquid and vapor densities are from eqs (3) and (4).…”

“…3 £n(P^-10) = a/T^+ b + c-T^+ d-T^+ e-T^+ f-(l -T^)^, (2) where e = 1.85 and, from least squares analysis, …”

“…The equation has been modified from earlier forms [26][27][28][29]. For any density (isochore) the coexistence temperature, T^(p)» is obtained by iteration from eqs (3) and (4) …”

“…The value for 3 was found by trial, while the value for n was determined from critical region behavior. …”

“…Results for the vapor pressures appear in table 1 at ID = 80, and for the heats of vaporization in table 10 at ID = 80. Saturated vapor densities from the thermal loop computations are replaced in table 3 at ID = 40 by derived data from the fitted vapor-pressure eq (2) and the virial eq (5a). Table 10 shows the fit of selected data.…”