No data were found in the literature for this binary mixture. ... The binary system HFE-7100 + 2-propanol shows positive azeotropes at every measured pressure ...
Isobaric Vapor-Liquid Equilibrium of binary mixtures HFE-7100 + 2-propanol
Electromechanical Engineering Department Escuela Politécnica Superior Avda. Cantabria s/n 09006 BURGOS (Spain) Phone +34 947258916
Natalia Muñoz(a), Adil Srhiyer(a), Eduardo Montero(a), Fernando Aguilar(a)
UNIVERSIDAD DE BURGOS www.ubu.es 1
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Abstract
(a)
Universidad de Burgos, Grupo de Ingeniería Energética
Experimental technique
Hydrofluoroether fluids (HFEs) are being used as third generation alternatives to replace CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons) and PFCs (perfluorocarbons) because of their nearly zero ozone depletion, relatively low global warming potential and short atmospheric lifetimes [1]. In addition, they may be industrially used as cleaning solvents in the electronic components, protective gas used in melting of alloys, decontamination of fluids and heat transfer fluids in the heat exchangers [2]. Though a variety of HFEs have been synthesized, their performance and environmental properties and hence their utility can vary widely. For example, 1-methoxy-nonafluorobutane, also known as HFE 7100, has zero ozone depletion potential and other favorable environmental properties. The high boiling point and low surface tension of HFE 7100 fluid make it ideal for use as cleaner fluid as pure component or in mixtures with other solvents. Moreover, its chemical and thermal stability, non-flammability and low toxicity make it useful for many other industrial uses, such as high-GWP refrigerants replacement and as heat transfer fluid. Experimental vapor-liquid equilibrium of the binary system HFE7100 + 2-propanol at 50, 101.325 and 200 kPa are reported in this work. Vapor-liquid equilibrium (VLE) have been measured with an isobaric ebullometer. Pressure stability is better than 0.06 kPa and temperature uncertainty is ±0.2 K. Composition of vapor and liquid phase is estimated by means of density and speed of sound measurements. No data were found in the literature for this binary mixture.
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A glass Fischer Labodest VLE apparatus model 602S was used in the equilibrium determinations. The equilibrium vessel is a dynamic recirculating still, and it is equipped with a Cottrell circulation pump. The equilibrium temperature was measured with a digital thermometer, with a four wire PT100 with an accuracy of ±0.02 K. A digital pressure controller Wika Mensor CPC3000 with an accuracy of ±0.001 kPa was used for the pressure measurement. When temperature remains constant for 30 min or longer, the condition of equilibrium is assumed, and then liquid and vapor samples are taken for analysis. Liquid and vapor-phase composition were determined indirectly by measure of density and speed of sound in an Anton Paar DSA 5000M. Data for the composition dependence of the density and speed of sound of studied systems have been measured previously. Densities and speeds of sound were measured to within ±0.000005 g·cm−3 and ±0.5 m·s-1 covering the whole composition range.
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Calculations from experimental results
Tsonopoulos’s Method (Tsonopolulos, 1974)
Materials Chemicals purchased from: 3MTM NovecTM Engineered Fluids
SIGMA-ALDRICH (series puriss)
HFE-7100
2-PROPANOL
>99.5% (G.C.)
>99.9% (G.C.)
Rackett’s equation Fredenslund et al., (1977)
Thermodynamic consistency
Wisniak, (1993)
PURISS P.A. >98.5% (GC) for all components
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Antoine’s equation
Figure 1. Experimental technique: Isobaric ebulliometer Fischer VLE 602
Experimental Results
Models used to correlate experimental VLE data 50 kPa
101,3 kPa
200200 kPakPa
Redlich-Kister (Redlich et al. 1948) Margules (Abott et al.1975) Wilson (Wilson, 1964) Van Laar (Van Laar, 1913) NRTL (Renon and Prausnitz, 1968) UNIQUAC (Abrams and Prausnitz, 1975) TABLE 1: Summary of parameters for the representation of GE by Redlich-Kister, Margules, Wilson and Van Laar equation, NRTL and UNIQUAC models for the binary system HFE-7100 (1) + 2-propanol (2) at different pressures.
Figure 2. Boiling temperature diagram of the binary system HFE-7100 (1) + 2-propanol(2) a) at 50 kPa, b) at 101.32 and c) at 200 kPa. (O) Experimental VLE data for the binary system, (_____) calculated conposition from Wilson s model. This system shows a positive azeotrope in every pressure.
50 kPa
101,3 kPa
200 kPa
Figure 3. Activity coefficients plots of the binary system 2-propanol (1) + Di-isopropyl ether (2) a) at 50 kPa, b) at 101.32 and c) at 200 kPa. (O) Experimental data, calculated values using: (------) Van Laar, (_____) Margules , (_____) Wilson, (- - - -) NRTL model and (-·-·-·-) UNIQUAC model..
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Discussion of Results
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References [1] W. Tsai, J. Hazard. Mater. A 2005, 119, 69–78. [2] 3M™ Novec™ Engineered Fluids,
The binary system HFE-7100 + 2-propanol shows positive azeotropes at every measured pressure, at temperature lower than boiling temperatures of both pure components.
http://solutions.3m.com/wps/portal/3M/en_US/3MNovec/Home (last visit 06/07/2014). [3] C. Tsonopoulos, AIChE J. 20 (1974) 263–272. [4] J. Wisniak, Ind. Eng. Chem. Res. 32 (1993) 1531-1533.
P = 50 kPa.
P = 101.32 kPa.
Positive Azeotrope
Positive Azeotrope
at x1=0.838 and Tb = 310.56 K •GE>0 for complete composition range
at x1=0.794 and Tb = 328.80 K •GE>0 for complete composition range
[5] A. Fredenslund, J. Gmehling, P. Rasmussen, Vapor–Liquid Equilibria Using UNIFAC. A
P = 200 kPa.
Group Contribution Method, Elsevier, Amsterdam, 1977. [6] J.A. Riddick, W.B. Bunger, T.K. Sakano, Organic Solvents, Willey, New York, 1986.
Positive Azeotrope
[7] O. Redlich, A.T. Kister, Ind. & Eng. Chem. 40 (1948) 345-348.
at x1=0.739 and Tb = 348.77 K
[8] G.M. Wilson, Am. Chem. Soc. 86 (1964) 127–130.
•GE>0 for complete composition range
[9] J.J. Van Laar, Z. Phys. Chem. 83 (1913) 599-608. [10] H. Renon, J.M. Prausnitz, AIChE J. 14 (1968) 135–144. [11] D.S. Abrams, J.M. Prausnitz, AIChE J. 21 (1975) 116–128.
Data Correlation: •Better results for Wilson than for Margules and Van Laar equation. •Better results for UNIQUAC model than for NRTL model.
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Acknowledgement N. Muñoz acknowledges support for this research to the University of Burgos, for the funding of her doctoral grant.
This work is part of the Doctoral Thesis of N. Muñoz
TH 20
EUROPEAN CONFERENCE ON THERMOPHYSICAL PROPERTIES
AUGUST 31st – SEPTEMBER 4th 2014
PORTO (PORTUGAL)
ECTP2014
