Liquid-Phase Thermodynamic Properties for Propane (1), n-Butane (2), and Isobutane (3)

Abstract

Hydrocarbons (HCs) are environmentally friendly natural refrigerants and are expected to be promising alternative candidates to replace some currently used halogenated hydrocarbon refrigerants. Some available data sets for HCs used to formulate the equations of state (EoS) for them are relatively old, so we point out that new data with less uncertainty are expected to play an essential role in updating the EoS for HCs. Therefore, a set of PVT property measurements for hydrocarbon refrigerants including propane, n-butane, and isobutane was conducted in the present study. A newly developed vibrating-tube densimeter was employed for the measurements, and then a total of 430 liquid PVT properties were obtained, including those at the saturation boundaries. The measurement range is (240 to 380) K for temperature and up to 7 MPa for pressure. The measurement uncertainty is about 3 mK for temperature, 0.26 kPa + 0.022% for pressure, and 0.1 kg‚m -3 + 0.024% for density. The present data were compared with available thermodynamic models that are currently considered to be the most reliable. A set of modified Tait equations of state for the liquid phase are also discussed.

Measurements of Vapor Pressures from 280 to 369 K and (p, ρ, T) Properties from 340 to 400 K at Pressures to 200 MPa for Propane

“…The behaviors of density values calculated from the pressure-explicit mBWR-type equation of state developed by Younglove and Ely [16] and the multi-parameter Helmholtz-type equation of state developed by Span and Wagner [17] are also included for comparisons. The new literature data (Claus et al [10], Glos et al [11], and Kayukawa et al [12]) reasonably agreed with the present measurements. In the higher pressure region above 103 MPa, the behavior of calculated density values from three models (by Younglove and Ely [16], Miyamoto and Watanabe [15], and Span and Wagner [17]) and the present measurements agreed reasonably as shown in Fig.…”

“…Figure 3 shows relative pressure deviations of the present measurements from the Wagner-type vapor-pressure correlation for propane proposed by Miyamoto and Watanabe [15]. The vapor-pressure data by Reamer et al [3], Helgeson and Sage [18], Teichmann [19], Kratzke [20], Thomas and Harrison [6], Glos et al [11], and Kayukawa et al [12] were also included in Fig. 3.…”

“…. , Younglove-Ely model [16]; --, Span-Wagner model [17]; , Claus et al [10]; , Glos et al [11]; * , Kayukawa et al [12]. +, Teichmann [19]; , Kratzke [20]; , Thomas and Harrison [6]; ♦, Glos et al [11]; ×, Kayukawa et al [12].…”

“…In previous publications [1,2] we reported measurements of the vapor pressure and ( p, ρ, T ) properties for isobutane by a metal-bellows variable volumometer at temperatures from 280 to 440 K at pressures up to Reamer [3] 306 Mercury piezometer 0.1-69 1-576 311-511 Dittmer [4] 336 Isochoric method 1.0-103 320-590 273-413 Ely [5] 222 Isochoric method 0.3-43 508-652 166-324 Thomas [6] 736 Mercury piezometer 0.6-40 35-549 258-623 Haynes [7] 196 Magnetic suspension densimeter 0.6-37 493-741 90-300 Kratzke [8] 60 Isochoric method 2.2-61 441-565 247-491 Straty [9] 144 Burnett expansion (isochoric) 0.2-35 2-347 363-598 Claus [10] 130 Single-sinker densimeter 2.0-30 24-506 340-520 Glos [11] 72 Two-sinker densimeter 0.2-12 3-727 95-340 Kayukawa [12] 200 MPa. In this paper, the results of (p, ρ, T) measurements for propane using the same apparatus are presented for the compressed liquid phase for temperatures from 340 to 400 K at pressures up to 200 MPa.…”

“…On the other hand, comparatively new information for (p, ρ, T) property measurements were reported from 2002 to 2005 as summarized in Table I. These sets of accurate measurements from three sources were obtained by means of buoyancy methods (single-sinker densimeter below 30 MPa [10] and two-sinker densimeter below 12 MPa [11]) and vibrating tube densimeter below 7 MPa [12].…”