Vapor−Liquid Equilibrium for the Difluoromethane (R32) + n-Butane (R600) System

Abstract

Vapor−liquid equilibria (VLE) for the difluoromethane (R32) + n-butane (R600) system that shows liquid-phase immiscibility below 246 K were measured at (263.15, 278.15, and 293.15) K by means of a static analytical method. The (T−P−x−y) VLE data were correlated using various equations of state and various mixing rules to compare the ability of these models to correlate data for this strongly nonideal system. The correlation of the VLE data and published VLLE data shows that the system is azeotropic at temperatures higher than the upper critical end point, UCEP, (246 K), heterohomoazeotropic between (246 and 230) K, and heteroazeotropic below 230 K. A comparison with the available VLE data in the literature was performed.

Assessment of Low Global Warming Potential Refrigerants for Drop-In Replacement by Connecting their Molecular Features to Their Performance

“…The last demonstration of the accuracy of the model in capturing the effect of dipolar interactions is demonstrated through predicting the VLE for binary mixtures of dipolar + nonpolar fluids. In this manner, the ability of the model to correctly approximate the contribution of dipole–dipole interactions can be isolated, as dipole interactions have a larger effect on the nonideality of their VLEs with nonpolar fluids. , For this end, binary mixtures of dipolar refrigerants with nonpolar n -alkanes (modeled as a chain-like LJ fluid, using parameters included in Table S2 in the SI) were predicted from the thermodynamic model for mixtures including ethane with R23 or R1234ze­(E) and n-butane with R32, R152a, R134a, and R1234yf as dictated by available experimental data. − Indeed, the agreement between the experimental VLE data and model predictions is excellent with AADs = 1.0%, as seen in Figure , merely from the accurate representation of the behavior of the pure refrigerants.…”

The study of binary interaction parameters on VLE for alternative refrigerant mixtures

“…The SRK, PR, and CSD equations of states with van der Waals mixing rules could reasonably calculate the VLE properties of the HCs + HFCs and DME + HFCs. The values of the optimum interaction parameter k ij HFC23 + HC170 48 [6] 0.195 2.151 0.0142 0.199 0.891 0.0132 0.179 1.875 0.0098 HFC23 + HC290 27 [7] 0.195 1.456 0.0055 0.199 2.389 0.0066 0.179 3.058 0.0090 HFC23 + HC600 28 [7] 0.195 3.333 0.0030 0.199 3.567 0.0051 0.179 4.533 0.0029 HFC23 + HC600a 23 [8] 0.195 3.176 0.0085 0.199 2.784 0.0075 0.179 3.438 0.0089 HFC32 + HC290 63 [9] 0.188 0.707 0.0026 0.195 0.858 0.0036 0.157 1.948 0.0117 HFC32 + HC600 32 [10] 0.188 5.201 0.0134 0.195 5.681 0.0124 0.157 6.231 0.0163 HFC32 + HC600a 26 [11] 0.188 2.806 0.0100 0.195 2.699 0.0097 0.157 3.130 0.0098 HFC125 + HC290 89 [9] 0.156 1.450 0.0074 0.158 1.184 0.0044 0.144 0.855 0.0044 HFC125 + HC600 29 [12,13] 0.156 0.900 0.0030 0.158 1.158 0.0033 0.144 0.946 0.0064 HFC125 + HC600a 23 [14] 0.156 2.182 0.0079 0.158 2.245 0.0062 0.144 1.294 0.0058 HFC134a + HC290 37 [15] 0.168 0.789 0.0048 0.171 0.660 0.0056 0.157 0.835 0.0053 HFC134a + HC600 41 [16] 0.168 0.850 0.0059 0.171 1.046 0.0044 0.157 2.145 0.0100 HFC134a + HC600a 24 [17] 0.168 2.240 0.0093 0.171 2.223 0.0077 0.157 3.236 0.0107 HFC143a + HC290 22 [15] 0.113 1.693 0.0035 0.117 1.314 0.0043 0.101 2.803 0.0070 HFC143a + HC600 47 [18] 0.113 1.502 0.0044 0.117 1.077 0.0056 0.101 1.941 0.0098 HFC143a + HC600a 16 [8] 0.113 2.250 0.0136 0.117 1.994 0.0133 0.101 3.198 0.0153 HFC152a + HC290 25 [19] 0.127 4.149 0.0011 0.132 4.802 0.0184 0.108 1.927 0.0082 HFC152a + HC600 34 [20] 0.127 0.695 0.0051 0.132 1.395 0.0055 0.108 0.976 0.0072 HFC152a + HC600a 32 [11] 0.127 1.706 0.0071 0.132 2.232 0.0072 0.108 1.803 0.0107 HFC227ea + HC290 58 [21] 0.135 1.137 0.0044 0.136 0.953 0.0028 0.122 1.049 0.0083 HFC227ea + HC600 45 [22] 0.135 1.065 0.0038 0.136 1.274 0.0060 0.122 1.093 0.0080 HFC227ea + HC600a 37 [14] 0.135 0.597 0.0055 0.136 0.547 0.0042 0.122 0.298 0.0055 HFC236ea + HC290 37 [23] 0.141 1.663 0.0050 0.143 1.802 0.0071 0.128 1.760 0.0061 HFC236fa + HC290 37 [24] 0.141 1.413 0.0052 0.143 1.492 0.0078 0.128 1.208 0.0055 HFC236fa + HC600a 13 [17] 0.141 1.734 0.0028 0.143 1.873 0.0052 0.128...…”

“…[3,4] However, the blended refrigerants are preferable to pure working fluids on account of energy saving and the flexibility of operation. [5] Because the vapor-liquid equilibrium (VLE) properties are important in the optimization of thermodynamic cycles, the literature on VLE experimental measurement data for new alternative refrigerant mixtures (HCs + HFCs [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] and DME + HFCs binaries [23,[25][26][27][28][29] ) have increased considerably in the recent years. Due to the time-consuming nature of experimental measurement, the predictive models are valuable tools for estimating the VLE properties.…”

Isothermal vapour+liquid equilibrium measurements and correlation for the pentafluoroethane+cyclopropane and the cyclopropane+1,1,1,2-tetrafluoroethane binary systems

“…[1][2][3][4][5][6][7][8][9][10]), in this paper isothermal VLE for systems formed by pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a) and cyclopropane (RC270) are presented. Only one data point is available in literature for the binary mixture RC270 + R134a whereas no data were found for the system R125 + RC270.…”