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Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Vapor Phase PvTx Measurements of Binary Blends of trans-1-Chloro-3,3,3-trifluoroprop-1-ene + Isobutane and cis-1,3,3,3-Tetrafluoroprop-1-ene + Isobutane J. Steven Brown,*,† Gianluca Coccia,‡ Sebastiano Tomassetti,‡ Mariano Pierantozzi,§ and Giovanni Di Nicola‡ †

Department of Mechanical Engineering, The Catholic University of America, Washington, DC United States Dipartimento di Ingegneria Industriale e Scienze Matematiche, Università Politecnica delle Marche, Ancona, Italy § Scuola di Ateneo Architettura e Design, Università degli studi di Camerino, Ascoli Piceno Italy ‡

S Supporting Information *

ABSTRACT: This paper provides eighty-four PvTx data points for binary blends of trans-1-chloro-3,3,3-trifluoroprop-1-ene (R1233zd(E)) and isobutane (R600a) in the vapor phase and ninety-seven PvTx data points for binary blends of cis-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(Z)) and R600a in the vapor phase. The R1233zd(E)/R600a data were recorded along six isochores (0.0499, 0.0536, 0.0927, 0.1263, 0.1431, 0.1744) m3·kg−1 for temperatures (303 < T < 383) K for six R600a mole fractions (0.125, 0.453, 0.564, 0.644, 0.746, 0.865). The R1234ze(Z)/R600a blends were recorded along five isochores (0.0759, 0.0907, 0.1272, 0.1288, 0.1520) m3·kg−1 for temperatures (303 < T < 383) K for six R600a mole fractions (0.118, 0.222, 0.427, 0.510, 0.658, 0.725). The data were regressed using several equations of state.

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INTRODUCTION There is growing interest in low global warming potential (GWP) working fluids for a number of higher-temperature heating, refrigerating, and power generating applications. However, because of increasing legislation and regulations,1−6 it is becoming increasingly more difficult to identify single-component working fluids able to meet all system design constraints and criteria.7,8 Therefore, it is becoming increasingly necessary to blend working fluids in order to tailor the blend properties so as to meet the various system design constraints and criteria. This paper furthers previous studies9−13 by the authors focused on blends possessing low global warming potentials (GWP). In the most recent of these studies,13 the authors focused on the hydrocarbon isobutane (R600a) blended with two fluorinated propene isomers: 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) and trans-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(E)). The present paper focuses once again on blends of R600a; however, it extends the previous study13 to include two halogenated propene isomers: trans-1-chloro-3,3,3-trifluoroprop1-ene (R1233zd(E)) and cis-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(Z)). It is worth noting that despite the presence of chlorine in R1233zd(E), it possesses a quite low ozone depletion potential (ODP) value because of its short atmospheric lifetime.14 R1234yf and R1234ze(E) have received considerable commercial development focus over the last 10−15 years including in low- and medium-temperature refrigeration and comfort cooling applications. One of the primary thermodynamic reasons for using these two refrigerants in the previously © XXXX American Chemical Society

mentioned applications is because they each possess a normal boiling point (NBP) temperature appropriate for these applications. While R1234ze(Z) and R1233zd(E) have not received nearly the same level of commercial development focus as have R1234yf and R1234ze(E), they have been, and are being, developed for a number of applications, particularly ones requiring higher NBP temperature working fluids, for example, high temperature heat pumping applications15 and Organic Rankine Cycle applications.16 The NBP temperatures for these four halogenated propene isomers in ascending order are (243.7, 254.2, 282.9, and 291.4) K for R1234yf, R1234ze(E), R1234ze(Z), and R1233zd(E), respectively.17 As for the other natural refrigerants/halogenated propene isomer blends considered by the authors,9−13 the currently considered R1233zd(E)/R600a and R1234ze(Z)/R600a blends can offer potential benefits over the single-component refrigerants alone, for example, the blends could potentially allow for the tailoring of thermodynamic and transport properties, flammability, and toxicity in ways which could allow for the blends to be used in a particular application even though the single-component options may not be appropriate or adequate for the application. Moreover, the blends could potentially lower cost, increase lubricant solubility, and improve heat exchanger performance Received: August 29, 2017 Accepted: November 23, 2017

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DOI: 10.1021/acs.jced.7b00769 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

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Table 1. R600a, R1233zd(E), and R1234ze(Z) Sample Descriptions chemical name

source

initial mole fraction purity

isobutane R1233zd(E)a

Matheson Gas Products Central Glass, Ltd.

0.999 >0.995

R1234ze(Z)b

Central Glass Ltd.

>0.99

a

purification method

final mole fraction purity

analysis method

>0.995

none none

>0.99

none

none several cycles of freezing, evacuation, melting, and ultrasonic agitation several cycles of freezing, evacuation, melting, and ultrasonic agitation

trans-1-Chloro-3,3,3-trifluoroprop-1-ene. bcis-1,3,3,3-Tetrafluoroprop-1-ene.

Table 2. Experimental Values of Pressure P, Specific Volume v, Temperature T, and Mole Fraction x in the Vapor Phase for R1233zd(E)/R600a Binary Blendsa T/K 303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15 303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15

P/kPa xR600a = 0.125 113.3 115.4 117.5 119.6 121.8 123.8 125.8 128.2 130.2 132.2 134.4 136.3 138.3 140.4 142.3 144.4 146.5 xR600a = 0.453 197.4 200.9 204.5 208.0 211.4 214.9 218.5 222.0 225.5 229.0 232.1 235.6 239.1 242.6 246.4 xR600a = 0.564 186.5 190.1 193.7 197.5 200.9 204.3 207.8 211.1 214.6 218.0 221.4 224.6 228.1

v/m3·kg−1

T/K

P/kPa

v/m3·kg−1

0.1740 0.1741 0.1741 0.1742 0.1742 0.1742 0.1743 0.1743 0.1744 0.1744 0.1744 0.1745 0.1745 0.1745 0.1746 0.1746 0.1747

338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

xR600a = 0.644 576.1 587.5 598.7 609.8 620.8 631.1 642.6 653.2 664.1 675.0

0.0499 0.0499 0.0499 0.0499 0.0499 0.0500 0.0500 0.0500 0.0500 0.0500

0.1261 0.1262 0.1262 0.1262 0.1262 0.1263 0.1263 0.1263 0.1264 0.1264 0.1264 0.1264 0.1265 0.1265 0.1265

318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

xR600a = 0.746 340.9 347.6 353.9 360.6 366.9 373.2 379.5 385.8 391.8 398.1 404.2 410.7 416.9 423.2

0.0926 0.0926 0.0926 0.0926 0.0926 0.0927 0.0927 0.0927 0.0927 0.0927 0.0928 0.0928 0.0928 0.0928

0.1429 0.1429 0.1430 0.1430 0.1430 0.1430 0.1431 0.1431 0.1431 0.1432 0.1432 0.1432 0.1433

333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

xR600a = 0.865 648.1 661.4 674.5 687.5 700.5 713.3 726.1 738.7 751.4 763.9 776.5

0.0535 0.0535 0.0536 0.0536 0.0536 0.0536 0.0536 0.0536 0.0536 0.0536 0.0536

Table 2. continued T/K

P/kPa

v/m3·kg−1

368.15 373.15 378.15 383.15

xR600a = 0.564 231.5 234.8 238.2 241.7

0.1433 0.1433 0.1434 0.1434

T/K

P/kPa

v/m3·kg−1

xR600a = 0.865

a

Expanded uncertainties are u(T) = 0.03 K, u(P) = 1 kPa, u(v) = 0.276 dm3·kg−1, and u(xR600a) = 0.009.

Figure 1. Vapor phase pressure P, specific volume v, temperature T, and mole fraction x data (Table 2) for binary blends of R1233zd(E)/ R600a: ●, xR600a = 0.125 and v = 0.1744 m3·kg−1; ×, xR600a = 0.453 and v = 0.1263 m3·kg−1; +, xR600a = 0.564 and v = 0.1431 m3·kg−1; ○, xR600a = 0.644 and v = 0.0499 m3·kg−1; ▲, xR600a = 0.746 and v = 0.0927 m3·kg−1; △, xR600a = 0.865 and v = 0.0536 m3·kg−1.

when compared to the single-component halogenated propene isomer working fluid options. Therefore, this paper wishes to contribute to the overall knowledge base regarding hydrocarbon/halogenated propene isomer blends by presenting vapor phase PvTx data for binary blends of R1233zd(E)/R600a and R1234ze(Z)/R600a, together with presenting several simple fitting models of the data.

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EXPERIMENTAL SECTION Materials. The samples of isobutane (R600a, CH(CH3)3, CAS number 75-28-5), trans-1-chloro-3,3,3-trifluoroprop-1-ene (R1233zd(E), CF3CHCHCl, CAS number 102687-65-0), and cis-1,3,3,3-tetrafluoroprop-1-ene, (R1234ze(Z), CF3CHCHF, CAS number 29118-25-0) are described in Table 1. To remove noncondensable gases, the R1233zd(E) and R1234ze(Z) samples were subjected to several cycles of freezing, evacuation, thawing, and ultrasonic stirring. B



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Table 3. Experimental Values of Pressure P, Specific Volume v, Temperature T, and Mole Fraction x in the Vapor Phase for R1234ze(Z)/R600a Binary Blendsa T/K 303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15 303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15 303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

P/kPa xR600a = 0.118 145.9 148.7 151.4 154.0 156.8 159.4 162.0 164.6 167.2 169.8 172.5 175.1 177.7 180.3 182.9 185.5 188.1 xR600a = 0.222 155.7 158.6 161.5 164.3 167.2 170.0 172.7 175.4 178.2 180.8 183.7 186.5 189.4 192.1 194.9 197.7 200.5 xR600a = 0. 427 206.5 210.5 214.4 218.3 222.2 226.0 229.8 233.6 237.3 241.1 244.7 248.6 252.3 256.0 259.8 263.6 267.4

v/m3·kg−1

T/K

0.1520 0.1520 0.1521 0.1521 0.1521 0.1522 0.1522 0.1522 0.1523 0.1523 0.1523 0.1524 0.1524 0.1524 0.1525 0.1525 0.1525

303.15 308.15 313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

0.1514 0.1514 0.1515 0.1515 0.1515 0.1516 0.1516 0.1516 0.1517 0.1517 0.1517 0.1518 0.1518 0.1518 0.1519 0.1519 0.1519

313.15 318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

xR600a = 0.510 213.5 217.4 221.3 225.2 229.2 233.1 237.0 240.9 244.7 248.6 252.4 256.3 260.1 263.9 267.8 271.7 275.5 xR600a = 0.658 398.1 406.6 414.5 423.1 430.7 438.4 446.0 453.6 461.2 468.5 476.0 483.4 490.9 498.2 505.8

0.1270 0.1270 0.1271 0.1271 0.1271 0.1271 0.1272 0.1272 0.1272 0.1272 0.1273 0.1273 0.1273 0.1274 0.1274 0.1274 0.1274

318.15 323.15 328.15 333.15 338.15 343.15 348.15 353.15 358.15 363.15 368.15 373.15 378.15 383.15

xR600a = 0.725 362.3 369.1 375.8 382.5 389.1 395.8 402.5 409.1 415.6 422.1 428.6 435.2 441.7 448.3

P/kPa

v/m3·kg−1 0.1286 0.1286 0.1286 0.1287 0.1287 0.1287 0.1287 0.1288 0.1288 0.1288 0.1288 0.1289 0.1289 0.1289 0.1290 0.1290 0.1290

Figure 2. Vapor phase pressure P, specific volume v, temperature T, and mole fraction x data (Table 3) for binary blends of R1234ze(Z)/ R600a; O, xR600a = 0.118 and v = 0.1523 m3·kg−1; + , xR600a = 0.222 and v = 0.1517 m3·kg−1; ●, xR600a = 0.427 and v = 0.1272 m3·kg−1; X, xR600a = 0.510 and v = 0.1288 m3·kg−1; ▲, xR600a = 0.658 and v = 0.0759 m3·kg−1; Δ, xR600a = 0.725 and v = 0.0907 m3·kg−1.

Table 4. Coefficients for Eq. 4

0.0757 0.0758 0.0758 0.0758 0.0758 0.0758 0.0758 0.0759 0.0759 0.0759 0.0759 0.0759 0.0759 0.0760 0.0760

R1233zd(E)/R600a R1234ze(Z)/R600a

0.0906 0.0906 0.0906 0.0907 0.0907 0.0907 0.0907 0.0907 0.0908 0.0908 0.0908 0.0908 0.0908 0.0909

D1

D2

D3

0.5600 0.3406

−0.0754 0.1204

0.5098 0.5389

Figure 3. Biases (ΔP/P = (Pcalc − Pexp)/Pexp) between Helmholtz free energy equation of state for R1233zd(E)23 and R600a25 coupled with a modified van der Waals one-fluid linear mixing model26 with optimized constants Kt = 1.03 and Kv = 1.11 and the data of Table 2 (Pexp): ●, xR600a = 0.125 and v = 0.1744 m3·kg−1; ×, xR600a = 0.453 and v = 0.1263 m3·kg−1; +, xR600a = 0.564 and v = 0.1431 m3·kg−1; ○, xR600a = 0.644 and v = 0.0499 m3·kg−1; ▲, xR600a = 0.746 and v = 0.0927 m3·kg−1; △, xR600a = 0.865 and v = 0.0536 m3·kg−1.

capable of operating temperatures from (210 to 380) K. Details regarding the experimental setup and associated uncertainties are reported elsewhere9−13,18,19 and thus will not be repeated here. Instead, only summary highlights are included below. The blends were prepared based on a gravimetric method. To begin, the isochoric sphere and tubing were first subjected to vacuum. Then the desired masses of refrigerants were discharged into the isochoric sphere, where the discharged masses were determined using an analytical balance possessing an

a

Expanded uncertainties are u(T) = 0.03 K, u(P) = 1 kPa, u(v) = 0.225 dm3·kg−1, and u(xR600a) = 0.008.

Experimental Apparatus and Procedure. The apparatus consisted of an isochoric sphere and two thermostatic baths C



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Figure 5. Biases (ΔP/P = (Pcalc − Pexp)/Pexp) between Peng− Robinson equation of state (Pcalc) for R1233zd(E)/R600a coupled with a van der Waals one-fluid linear mixing model28 with binary interaction parameters optimized (Table 4) for each isochore (model PR2) and the data of Table 2 (Pexp): ●, xR600a = 0.125 and v = 0.1744 m3·kg−1; ×, xR600a = 0.453 and v = 0.1263 m3·kg−1; +, xR600a = 0.564 and v = 0.1431 m3·kg−1; ○, xR600a = 0.644 and v = 0.0499 m3·kg−1; ▲, xR600a = 0.746 and v = 0.0927 m3·kg−1; △, xR600a = 0.865 and v = 0.0536 m3·kg−1.

Figure 4. Biases (ΔP/P = (Pcalc−Pexp)/Pexp) between Helmholtz free energy equation of state for R1234ze(Z)24 and R600a25 coupled with a modified van der Waals one-fluid linear mixing model26 with optimized constants Kt = 0.91 and Kv = 1.19 and the data of Table 2 (Pexp): ○, xR600a = 0.118 and v = 0.1523 m3·kg−1; +, xR600a = 0.222 and v = 0.1517 m3·kg−1; ●, xR600a = 0.427 and v = 0.1272 m3·kg−1; ×, xR600a = 0.510 and v = 0.1288 m3·kg−1; ▲, xR600a = 0.658 and v = 0.0759 m3·kg−1; △, xR600a = 0.725 and v = 0.0907 m3·kg−1.

accuracy of ±0.3 mg. The total sample mass was determined by subtracting the amounts of refrigerants estimated to remain in the tubing, which were estimated to be between (0.01 and 0.06) g depending on the charging temperature, pressure, and molar mass of the fluid, from the discharged refrigerant masses. Regardless, the expanded uncertainty in mass at the 95% confidence level was estimated to be less than 0.9 mg. The temperature measurements were made using a 25 ohm platinum resistance thermometer (Hart Scientific 5680), the pressure measurements were made using a Ruska 7000 pressure transducer, and the volume of the isochoric sphere was determined to be 273.5 cm3 at 298 K. The expanded uncertainties at the 95% confidence level for the temperature, pressure, and volume measurements were 0.03 K, 1 kPa, and 0.3 cm3, respectively. The expanded uncertainty of the pressure measurements included a contribution due to changes in the thermostatic bath temperature. The uncertainty in the specific volume is a function of the uncertainties in the volume estimation and the mass measurement. The expanded uncertainty in the specific volume was calculated for each isochore from the following equation:13 ⎡⎛ u(v) ⎞2 ⎛ u(M )v ⎞2 ⎤ ⎟ +⎜ ⎟⎥ u(v)2 = v 2⎢⎜ ⎝ V ⎠ ⎥⎦ ⎢⎣⎝ V ⎠

Figure 6. Biases (ΔP/P = (Pcalc − Pexp)/Pexp) between Peng− Robinson equation of state (Pcalc) for R1234ze(Z)/R600a coupled with a van der Waals one-fluid linear mixing model28 with binary interaction parameters optimized (Table 4) for each isochore (model PR2) and the data of Table 2 (Pexp): ○, xR600a = 0.118 and v = 0.1523 m3·kg−1; +, xR600a = 0.222 and v = 0.1517 m3·kg−1; ●, xR600a = 0.427 and v = 0.1272 m3·kg−1; ×, xR600a = 0.510 and v = 0.1288 m3·kg−1; ▲, xR600a = 0.658 and v = 0.0759 m3·kg−1; △, xR600a = 0.725 and v = 0.0907 m3·kg−1.

(1)

where the u(v) is the expanded specific volume uncertainty in dm3·kg−1, v is the specific volume in dm3·kg−1, V is the total

Table 5. Binary Interaction Parameters (k12) for One-Fluid Mixing Model Coupled with Peng−Robinson Equation of State R1233zd(E)/R600a

R1234ze(Z)/R600a

xR600a

v/m3·kg−1

k12 PR1

k12 PR2

xR600a

v/m3·kg−1

k12 PR1

k12 PR2

0.125 0.453 0.564 0.644 0.746 0.865

0.1744 0.1263 0.1431 0.0499 0.0927 0.0536

−0.1865 −0.1865 −0.1865 −0.1865 −0.1865 −0.1865

−0.7117 −0.3870 0.3028 −0.1983 0.0089 −0.1335

0.118 0.222 0.427 0.510 0.658 0.725

0.1523 0.1517 0.1272 0.1288 0.0759 0.0907

−0.1841 −0.1841 −0.1841 −0.1841 −0.1841 −0.1841

−0.8116 −0.0989 0.0186 −0.2610 0.0348 0.0135

D



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Table 6. Coefficients for Bblend [Eq. 6] and for Cblend [Eq. 7] B1

B2

B3

B4

B5

R1233zd(E)/R600a R1234ze(Z)/R600a

−3.7808 0.51083 C1

−1786.1 −269.91 C2

0.16910 −7.3826 C3

−5.5388 7.5947 C4

30.348 −4.9763 C5

R1233ze(E)/R600a R1234ze(Z)/R600a

9.1326 −22.690

3570.5 −7295.9

−141.45 95.182

234.06 −108.62

−156.41 186.82

Figure 7. (a) Constant Bblend [eq 6] for binary blends of R1233zd(E)/R600a as a function of mole fraction x of R600a and temperature T (each symbol represents one of the 17 measured isotherms ranging from 303.2 to 383.2 K.) (b) Constant Cblend [eq 7] for binary blends of R1233zd(E)/ R600a as a function of mole fraction x of R600a and temperature T (each symbol represents one of the 17 measured isotherms ranging from 303.2 to 383.2 K.) (c) Constant Bblend [eq 6] for binary blends of R1234ze(Z)R600a as a function of mole fraction x of R600a and temperature T (each symbol represents one of the 17 measured isotherms ranging from 303.2 to 383.2 K.) (d) Constant Cblend [eq 7] for binary blends of R1234ze(Z)/ R600a as a function of mole fraction x of R600a and temperature T (each symbol represents one of the 17 measured isotherms ranging from 303.2 to 383.2 K.). 2 ⎤ ⎛ vu(m) ⎞2 ⎡⎛ 1⎞ ⎟ ⎢⎜1 + ⎟ + (1 + α)2 ⎥ u(x R600a) = ⎜ ⎝ V ⎠ ⎣⎝ α⎠ ⎦

volume of the isochoric sphere, tubing and pressure transducer cavity, u(M) = 2u(m) and u(m) is the uncertainty of mass in kilograms. On the basis of eq 1, the expanded uncertainties in the specific volume measurement at the 95% confidence level (coverage factor k = 2) for binary blends of R1233zd(E)/R600a and R1234ze(Z)/R600a ranged from (0.057 to 0.276) dm3·kg−1 and from (0.091 to 0.225) dm3·kg−1, respectively. The uncertainty in the molar fraction is a function of the mass of the blend sample charged into the isochoric sphere, on the specific volume of the blend sample, and on the molar fraction itself. The expanded uncertainties in the molar fraction were determined by13

2

( )x α= MR600a M2−3

(2)

R600a

(1 − x R600a)

(3)

where u(xR600a) is the expanded molar fraction uncertainty of isobutane, MR600a is the molar mass of isobutane, M2−3 are the molar masses of R1233ze(E) and R1234ze(Z) and xR600a is the molar fraction of isobutane. On the basis of eq 2, the expanded E



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uncertainties at the 95% confidence level (coverage factor k = 2) for the six isobutane molar fractions of R1233zd(E)/R600a blends and R1234ze(Z)/R600a blends ranged from (0.001 to 0.009) and from (0.001 to 0.008), respectively. Once the desired thermostatic bath temperature was achieved but prior to making measurements, a circulating pump was activated for 15 min after which the test sample was allowed to stabilize for 20 min. After recording the measured data, the thermostatic bath temperature was changed to the next desired set temperature. The test procedure was then repeated. The vapor pressures, liquid densities, and vapor phase PvTx behaviors of the pure components R1233zd(E) and R1234ze(Z) have been previously measured using this apparatus.20−22

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RESULTS AND DISCUSSION Experimental Data. Table 2 and Figure 1 provide eightyfour PvTx data points for binary blends of R1233zd(E)/R600a in the vapor phase and Table 3 and Figure 2 provide ninetyseven PvTx data points for binary blends of R1234ze(Z)/R600a in the vapor phase. The R1233zd(E)/R600a data were recorded along six isochores (0.0499, 0.0536, 0.0927, 0.1263, 0.1431, 0.1744) m3·kg−1 for temperatures (303 < T < 383) K for six R600a mole fractions (0.125, 0.453, 0.564, 0.644, 0.746, 0.865). The R1234ze(Z)/R600a blends were recorded along five isochores (0.0759, 0.0907, 0.1272, 0.1288, 0.1520) m3·kg−1 for temperatures (303 < T < 383) K for six R600a mole fractions (0.118, 0.222, 0.427, 0.510, 0.658, 0.725). Summary of Thermodynamic Behavior of Blends. The experimental vapor phase pressures of the halogenated propene isomer/isobutane blends vary between the values of the lower-pressure component (the halogenated propene isomers) and the higher-pressure component (isobutane) in a nonlinear fashion as a function of the isobutane mole fraction. In particular, the pressures of the blends vary from being about 5% to about 75% of the way between the lower-pressure and higher-pressure values as described by the following empirical equation:

Figure 8. Biases (ΔP/P = (Pcalc − Pexp)/Pexp) between the virial equation of state (Pcalc) of eq 4 and the data of Table 2 (Pexp) for binary blends of R1233zd(E)/R600a: ●, xR600a = 0.125 and v = 0.1744 m3·kg−1; ×, xR600a = 0.453 and v = 0.1263 m3·kg−1; +, xR600a = 0.564 and v = 0.1431 m3·kg−1; ○, xR600a = 0.644 and v = 0.0499 m3·kg−1; ▲, xR600a = 0.746 and v = 0.0927 m3·kg−1; △, xR600a = 0.865 and v = 0.0536 m3·kg−1.

and R1234ze(Z)/R600a (Table 3) are 7.73% and 6.18%, respectively. While the ideal gas model cannot accurately predict the experimental data, it is included to demonstrate that the simplest model is unable to predict the experimental data. Fundamental Helmholtz Free Energy Equation of State. Figures 3 and 4 present biases between the REFPROP17 Helmholtz Free Energy (FEQ) EoS for R1233zd(E),23 R1234ze(Z),24 and R600a25 coupled with a modified onefluid van der Waals mixing model26 for blends of R1233zd(E)/ R600a (Figure 3) and R1234ze(Z)/R600a (Figure 4). Note: see the Supporting Information for details of the FEQ EoS. The mixing model constants Kt and Kv were optimized for each blend by minimizing the mean ARDs. The results were Kt = 1.03 and Kv = 1.11 and Kt = 0.91 and Kv = 1.19 for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a, respectively. The mean biases between the regressed FEQ EoS and the experimental data for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a are −0.204% and 0.131%, respectively. The mean ARDs between the regressed FEQ EoS and the experimental data for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a are 0.548% and 0.286%, respectively. Peng−Robinson Equation of State. The data were regressed using a Peng−Robinson (PR) EoS27 coupled with a one-fluid linear van der Waals mixing model.28 (Note: see the Supporting Information for details of the PR EoS.) Two such models were developed: the first model (PR1) is based on a mean binary interaction parameter (k12) determined by minimizing the mean ARD of the entire data set and the second model (PR2) is based on employing k12 values for each isochore determined by minimizing the mean ARD of each isochore. Table 5 presents k12 for both models for both blends and Figures 5 and 6 present biases for PR2 for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a, respectively. The mean biases between the regressed PR2 EoS and the experimental data for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a are −0.022% and −0.017%, respectively. The mean ARDs between the regressed PR2 EoS and the experimental data for blends of R1233zd(E)/ R600a and R1234ze(Z)/R600a are 0.101% and 0.053%, respectively.

Pblend − PR1233zd(E)or R1234ze(Z) PR600a − PR1233zd(E)or R1234ze(Z) 3 2 = D1x R600a + D2x R600a + D3x R600a

(4)

where the coefficients are provided in Table 4. Ideal Gas Model. The data were first regressed to the Ideal Gas Law. The mean relative deviation (mean bias) is defined as ⎛ n ΔP ⎜⎜∑ i = ⎝ i = 1 Pi

Pcalc, i − Pexp, i ⎞ ⎟⎟ Pexp, i ⎠

n

∑ i=1

and the mean absolute relative deviation (mean ARD) is defined as ⎛ n ΔP i ⎜∑ = ⎜ P i ⎝ i=1

n

∑ i=1

Pcalc, i − Pexp, i ⎞ ⎟ ⎟ Pexp, i ⎠

The mean biases between the Ideal Gas Law (Pcalc) and the experimental data for blends of R1233zd(E)/R600a (Table 2) and R1234ze(Z)/R600a (Table 3) are 7.73% and 6.18%, respectively. The mean ARDs between the Ideal Gas Law (Pcalc) and the experimental data for blends of R1233zd(E)/R600a (Table 2) F



Article

where T is in K. The B and C coefficients (Table 6) were determined by minimizing the mean ARD for each refrigerant pair. Figure 7 panels a and b show Bblend and Cblend for R1233zd(E)/ R600a and Figure 7 panels c and d show Bblend and Cblend for R1234ze(Z)/R600a. Figure 8 reports biases between the Virial EoS and experimental data for R1233zd(E)/R600a blends. For this refrigerant pair, the mean bias is −0.086% and the mean ARD is 0.086%. Figure 9 reports biases between the Virial EoS and experimental data for R1234ze(Z)/R600a blends. For this refrigerant pair, the mean bias is 0.000% and mean ARD is 0.059%. Summary of Model Results. Table 7 shows percentages of the data falling within specified bounds for the various fitting models for blends of R1233zd(E)/R600a and R1234ze(Z)/ R600a. The models PR2 and virial are the best performers with greater than 99% of the data for both blends falling within ±1% for PR2 and within ±0.5% for virial. The PR and FEQ models are capable of predicting over 99% of the data for both blends within ±1.5%, which is acceptable accuracy for a number of engineering applications. Finally, the ideal gas model is unable to predict any of the data well enough even for engineering calculations. Table 8 shows the mean ARDs for the various models for blends of R1233zd(E)/R600a and R1234ze(Z)/ R600a. The models PR2 and virial are the best performers. The mean ARD for PR2 for blends of R1233zd(E)/R600a is 0.166% and is 0.078% for blends of R1234ze(Z)/R600a. The mean ARD for virial for blends of R1233zd(E)/R600a is 0.086% and is 0.059% for blends of R1234ze(Z)/R600a.

Figure 9. Biases (ΔP/P = (Pcalc − Pexp)/Pexp) between the virial equation of state (Pcalc) of eq 4 and the data of Table 3 (Pexp) for binary blends of R1234ze(Z)/R600a: ○, xR600a = 0.118 and v = 0.1523 m3·kg−1; +, xR600a = 0.222 and v = 0.1517 m3·kg−1; ●, xR600a = 0.427 and v = 0.1272 m3·kg−1; ×, xR600a = 0.510 and v = 0.1288 m3·kg−1; ▲, xR600a = 0.658 and v = 0.0759 m3·kg−1; △, xR600a = 0.725 and v = 0.0907 m3·kg−1.

Virial Equation of State. The data of Tables 2 and 3 were regressed to the following truncated virial EoS: P=

⎞ B blend C RT ⎛ ⎜1 + ⎟ + blend 2 v ⎝ v v ⎠

(5) −1

■

−1

where P is in kPa, R is in kJ·kmol ·K , v and Bblend is in m3·kmol−1, and Cblend is in m6·kmol−2. Following our earlier work,12,13 the constants Bblend and Cblend were regressed to the following equations: B 2 B blend = B1 ln T + 2 + B3x R600a + B4 x R600a + B5 (6) T C blend = C1 ln T +

C2 2 + C3x R600a + C4x R600a + C5 T

CONCLUSIONS This paper presents PvTx data in the vapor phase for two lowGWP working fluid blends. Each blend consists of the hydrocarbon isobutane and a low-GWP halogenated propene isomer (either trans-1-chloro-3,3,3-trifluoroprop-1-ene [R1233zd(E)] or cis-1,3,3,3-tetrafluoroprop-1-ene [R1234ze(Z)]). R1233zd(E) and R1234ze(Z) each have normal boiling point temperatures more suited for high-temperature applications or ones requiring

(7)

Table 7. Percentage of Measured Data Falling Within Specified Bounds for Binary Blends of R1233zd(E)/R600a and R1234ze(Z)/R600a for Several Equations of Statea R1233ze(E)/R600a

R1234ze(Z)/R600a

bounds

ideal gas

PR1

PR2

FEQ

virial

ideal gas

PR1

PR2

FEQ

virial

±0.025% ±0.05% ±0.25% ±0.50% ±1.00% ±1.50% ±2.50%

0.0 0.0 0.0 0.0 0.0 0.0 0.0

2.4 3.6 28.6 48.8 81.0 100.0 100.0

19.0 33.3 77.4 92.9 100.0 100.0 100.0

2.4 6.0 31.0 60.7 79.8 100.0 100.0

33.3 52.4 91.7 98.8 100.0 100.0 100.0

0.0 0.0 0.0 0.0 0.0 0.0 0.0

4.1 12.4 32.0 49.4 84.5 99.0 100.0

37.1 55.7 92.8 98.9 100.0 100.0 100.0

8.2 13.4 49.5 86.6 100.0 100.0 100.0

33.0 55.7 97.9 100.0 100.0 100.0 100.0

a PR1 is the Peng−Robinson EoS with a mean interaction parameter for R1233zd(E)/R600a of −0.186 and for R1234ze(Z)/R600a of −0.184, PR2 is the Peng−Robinson EoS with binary interaction parameters optimized for each isochore, FEQ is the fundamental Helmholtz EoS contained in REFPROP,27 and Virial is the truncated Virial EoS described in eq 5.

Table 8. Mean ARDs between Models and Measured Data for Blends of R1233zd(E)/R600a and R1234ze(Z)/R600aa R1233zd(E)/R600a

R1234ze(Z)/R600a

ideal gas

PR1

PR2

FEQ

virial

ideal gas

PR1

PR2

FEQ

virial

7.73

0.578

0.166

0.548

0.086

6.18

0.602

0.078

0.286

0.059

a PR1 is the Peng−Robinson EoS with a mean interaction parameter for R1233zd(E)/R600a of −0.186 and for R1234ze(Z)/R600a of −0.184, PR2 is the Peng−Robinson EoS with binary interaction parameters optimized for each isochore, FEQ is the fundamental Helmholtz EoS contained in REFPROP,27 and virial is the truncated virial EoS described in eq 5.

G



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(8) McLinden, M. O.; Brown, J. S.; Brignoli, R.; Kazakov, A. F.; Domanski, P. A. Limited options for low-global-warming-potential refrigerants. Nat. Commun. 2017, 8, 14476. (9) Di Nicola, G.; Di Nicola, C.; Arteconi, A.; Stryjek, R. PVTx measurements of the carbon dioxide + 2,3,3,3-Tetrafluoroprop-1-ene binary system. J. Chem. Eng. Data 2012, 57, 450−455. (10) Di Nicola, G.; Passerini, G.; Polonara, F.; Stryjek, R. PVTx measurements of the carbon dioxide + trans-1,3,3,3-Tetrafluoroprop1-ene binary system. Fluid Phase Equilib. 2013, 360, 124−128. (11) Brown, J. S.; Corvaro, F.; Di Nicola, G.; Giuliani, G.; Pacetti, M. PVT measurements of trans-1,3,3,3-tetrafluoroprop-1-ene + methane and trans-1,3,3,3-tetrafluoroprop-1-ene + nitrogen binary pairs. J. Chem. Eng. Data 2014, 59, 3798−3804. (12) Brown, J. S.; Coccia, G.; Di Nicola, G.; Pierantozzi, M.; Polonara, F. Vapor phase PvTx measurements of binary blends of 2,3,3,3-tetrafluoroprop-1-ene + propane and cis-pentafluoroprop-1-ene + propane. J. Chem. Eng. Data 2016, 61, 3346−3354. (13) Brown, J. S.; Coccia, G.; Tomassetti, S.; Pierantozzi, M.; Di Nicola, G. Vapor phase PvTx measurements of binary blends of 2,3,3,3-tetrafluoroprop-1-ene + isobutane and trans-1,3,3,3-tetrafluoroprop-1-ene + isobutane. J. Chem. Eng. Data 2017, 62, 3577−3584. (14) Orkin, V. L.; Martynova, L. E.; Kurylo, M. J. Photochemical properties of trans-1-chloro-3,3,3-trifluoropropene (trans-CHCL CHCF3): OH reaction rate constant, UV and IR absorption spectra, global warming potential, and ozone depletion potential. J. Phys. Chem. A 2014, 118, 5263−5271. (15) Brown, J. S.; Zilio, C.; Cavallini, A. The fluorinated olefin R1234ze(Z) as a high-temperature heat pumping refrigerant. Int. J. Refrig. 2009, 32, 1412−1422. (16) Eyerer, S.; Wieland, C.; Vandersickel, A.; Spliethoff, H. Experimental study of an ORC (Organic Rankine Cycle) and analysis of R1233zd-E as a drop-in replacement for R245fa for low temperature heat utilization. Energy 2016, 103, 660−671. (17) Lemmon, E. W.; Huber, M. L.; McLinden, M. O. NIST Standard Reference Database 23, Reference Fluid Thermodynamic and Transport Properties (REFPROP), version 9.1; National Institute of Standards and Technology: Gaithersburg, MD, 2010 (R1233zd(E).fld file updated November 6, 2015; R1234zee.fld file updated July 7, 2014; isobutan.fld file updated December 2, 2006). (18) Giuliani, G.; Kumar, S.; Polonara, F. A constant volume apparatus for vapour pressure and gas phase P-v-T measurements: Validation with data for R22 and R134a. Fluid Phase Equilib. 1995, 109, 265−279. (19) Di Nicola, G.; Polonara; Ricci, R.; Stryjek, R. PVTx measurements for the R116 + CO2 and R41 + CO2 systems. New isochoric apparatus. J. Chem. Eng. Data 2005, 50, 312−318. (20) Di Nicola, G.; Fedele, L.; Brown, J. S.; Bobbo, S.; Coccia, G. Saturated pressure measurements of trans-1-chloro-3,3,3-trifluoroprop1-ene (R1233zd(E)). J. Chem. Eng. Data 2017, 62, 2496−2500. (21) Fedele, L.; Di Nicola, G.; Brown, J. S.; Bobbo, S.; Zilio, C. Measurements and correlations of cis-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(Z)) saturation pressure. Int. J. Thermophys. 2014, 35, 1−12. (22) Fedele, L.; Brown, J. S.; Di Nicola, G.; Bobbo, S.; Scattolini, M. Measurements and correlations of cis-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(Z)) subcooled liquid density and vapor phase PvT. Int. J. Thermophys. 2014, 35, 1415−1434. (23) Mondéjar, M. E.; McLinden, M. O.; Lemmon, E. W. Thermodynamic properties of trans-1-chloro-3,3,3-trifluoropropene (R1233zd(E)): Vapor pressure, (p, ρ, T) behavior, and speed of sound measurements, and equation of state. J. Chem. Eng. Data 2015, 60, 2477−2489. (24) Akasaka, R.; Higashi, Y.; Miyara, A.; Koyama, S. A fundamental equation of state for cis-1,3,3,3-tetrafluoropropene (R-1234ze(Z)). Int. J. Refrig. 2014, 44, 168−176. (25) Buecker, D.; Wagner, W. Reference equations of state for the thermodynamic properties of fluid phase n-butane and isobutane. J. Phys. Chem. Ref. Data 2006, 35, 929−1019. (26) McLinden, M. O.; Klein, S. A. A next generation refrigerant properties database. Proceedings of the 1996 International Refrigeration

low volumetric cooling capacities more so than for low- and medium-temperature air conditioning and refrigerating applications or ones requiring small volumetric cooling capacities. Thus, this paper presents data and fitting models for blends of R1233zd(E)/R600a and R1234ze(Z)/R600a, as the blended working fluids could potentially be better alternatives for some higher-temperature heating, refrigerating, and power generating applications than the single-component halogenated propene isomers by themselves as the isobutane can potentially serve to reduce the costs, improve lubricant solubility, and improve heat exchanger performance.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.7b00769. Details of the Fundamental Helmholtz Free Energy Equation of State and of the Peng−Robinson Equation of State (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*Tel. + 001 202 3195247. Fax +001 202 3194499. E-mail: [email protected]. ORCID

J. Steven Brown: 0000-0003-4914-7778 Funding

This work was supported by MIUR of Italy within the framework of PRIN2015 project “Clean Heating and Cooling Technologies for an Energy Efficient Smart Grid”. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS The authors thank Central Glass, Ltd. for donating the R1233zd(E) and R1234ze(Z) samples.

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REFERENCES

(1) Kyoto Protocol; United Nations Framework Convention on Climate Change. unfccc.int/kyoto_protocol/items/2830.php (accessed June 30, 2017). (2) No 2002/358/EC: Council Decision of 25 April 2002 concerning the approval, on behalf of the European Community, of the Kyoto Protocol to the United Nations Framework Convention on Climate Change and the joint fulfilment of commitments thereunder. Off. J. Eur. Union: Legis. 2002, 130, 1−20. (3) Regulation (EC) No 842/2006 of The European Parliament and of the Council of 17 May 2006 on Certain Fluorinated Greenhouse Gases. Off. J. Eur. Union: Legis. 2006, 161, 1−11. (4) Directive 2006/40/EC of The European Parliament and of the Council of 17 May 2006 Relating to Emissions from Air-Conditioning Systems in Motor Vehicles & Amending Council Directive 70/156/ EC. Off. J. Eur. Union: Legis. 2006, 161, 12−18. (5) Regulation (EU) No 517/2014 of the European Parliament and of the Council of 16 April 2014 on fluorinated greenhouse gases and repealing Regulation (EC) No 842/2006 Text with EEA relevance. Off. J. Eur. Union: Legis. 2014, 150, 195−230. (6) Paris Agreement; United Nations Framework Convention on Climate Change. http://unfccc.int/paris_agreement/items/9485.php (accessed June 30, 2017). (7) Brown, J. S. Fourth ASHRAE/NIST Refrigerants Conference: “Moving Towards Sustainability. HVAC&R Res. 2013, 19, 101−102. H



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