Fluid Phase Equilibria 341 (2013) 30–34
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Fluid Phase Equilibria
j ournal homepage: www.elsevier.com/locate/fluid
Investigation on vapor–liquid equilibrium for
2-propanol + 1-butanol + 1-pentanol at 101.3 kPa
∗
Juan Wang, Zonghong Bao
College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China
a r t i c l e i n f o a b s t r a c t
Article history: Isobaric vapor–liquid equilibrium (VLE) data for 2-propanol + 1-butanol, 2-propanol + 1-pentanol, 1-
Received 26 September 2012
butanol + 1-pentanol and 2-propanol + 1-butanol + 1-pentanol were measured at 101.3 kPa by using an
Received in revised form 5 December 2012
improved Rose still. All the binary VLE data have passed the traditional area test proposed by Herington.
Accepted 18 December 2012
The interaction parameters for the Wilson, NRTL and UNIQUAC equations were determined by regress-
Available online 7 January 2013
ing the binary VLE data. The prediction for ternary system was given by using the three pairs of binary
parameters correlated. And the ternary data predicted agreed well with the experiment data. Keywords: © 2013 Elsevier B.V. All rights reserved. 2-Propanol 1-Butanol 1-Pentanol
Vapor–liquid equilibrium
1. Introduction 1-pentanol and ternary mixture of 2-propanol + 1-butanol + 1-
pentanol were obtained at 101.3 kPa. The experimental values were
Currently the international oil price has been rising, and the correlated by the Wilson, NRTL and UNIQUAC equations, in which
domestic oil resources are increasingly scarce. All these lead to a the binary parameters were obtained through the maximum like-
trend about producing mixed alcohols by using coal. The C1–C8 lihood. The quality of the experimental binary values was verified
mixed alcohols were produced at the same time by a new coal by the Herington method [5].
chemical synthesis technology in a set of device. This production
has already begun to accelerate the domestic industrial process [1].
2. Experimental
Mixed alcohols can continue to conduct multi-fractionations
and result in a series of single alcohol include methanol, ethanol,
2.1. Chemicals
propanol, etc. But the vapor–liquid equilibrium (VLE) data play
an important role in the design and optimized operations of
The physical properties of chemical reagents used are given
distillation processes. So far many useful VLE data among the
in Table 1. Methanol and 1-pentanol were supplied by Shanghai
mixed alcohols have been presented. However, for 2-propanol + 1-
Lingfeng Chemical Co. Ltd. 2-Propanol and 1-butanol were supplied
pentanol system, there is only one report about VLE data in 313.15 K
by Shanghai Shenbo Chemical Co. Ltd. Methanol and 2-propanol
[2], and no report is in isobaric condition. To 1-butanol + 1-pentanol
were used without further purification. 1-Butanol and 1-pentanol
system, data in low pressure are available [3], but they may not
were further purified by distillation in a column. All the reagents
meet the requirement of design calculations. As for 2-propanol + 1-
were dried on 0.4 nm molecular sieves and degassed by ultrasound
butanol system, Wang et al. [4] determined temperature and
before use. The purity of chemicals used was checked by the gas
liquid phase mole fraction in 101.3 kPa without giving vapor-
chromatography equipped with a thermal conductivity detector
phase mole fraction. Therefore, it is necessary to measure the VLE
and a stainless steel column. The refractive indices and normal boil-
data for 2-propanol + 1-butanol, 2-propanol + 1-pentanol, and 1-
ing points were measured by the WYA Abbe refractometer and the
butanol + 1-pentanol at atmospheric pressure condition.
improved Rose still, respectively.
In this paper, isobaric VLE results for binary mixture of
2-propanol + 1-butanol, 2-propanol + 1-pentanol and 1-butanol +
2.2. Apparatus and procedures
In this study, the VLE data were obtained with a glass recircula-
∗
tion apparatus called improved Rose still described by Zhang et al.
Corresponding author. Tel.: +86 025 83587190.
E-mail address: [email protected] (Z. Bao). [7]. A mercury thermometer was used to measure the equilibrium
0378-3812/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.fluid.2012.12.020
J. Wang, Z. Bao / Fluid Phase Equilibria 341 (2013) 30–34 31
Table 1
Physical properties of experimental materials.
Compound Purity (mass %) Water (mass %) nD (298.15 K) Tb/K (101.3 kPa)
Experiment Literature [6] Experiment Literature [6]
Methanol >99.5 <0.1% 1.3288 1.3286 337.69 337.66
2-Propanol >99.7 <0.1% 1.3776 1.3775 355.50 355.55
1-Butanol >99.6 0.1% 1.3995 1.3993 390.86 390.85
1-Pentanol >99.6 0.1% 1.4097 1.4099 411.10 411.15
Note: u(w) = ±0.001, u(nD) = ±0.0001, u(Tb) = ±0.01 K.
Table 2
temperature with an accuracy of temperature of 0.1 K, and con-
VLE data for 2-propanol (1) + 1-butanol (2), 2-propanol (1) + 1-pentanol (2), and 1-
ducted exposed neck correction to obtain the true temperature. The
butanol (1) + 1-pentanol (2) system at 101.3 kPa.
experiment pressure was controlled by a constant pressure system
T/K x y T/K x y
(a vacuum pump, a U-tube, and a buffer tank), and the precision 1 1 1 1
±
was within 133 Pa. 2-Propanol (1) + 1-butanol (2)
In the experiments, all the analytical work was carried out by 390.86 0 0 370.75 0.4002 0.7221
389.12 0.0227 0.0672 369.13 0.4471 0.7615
a gas chromatograph (GC6890, supplied by Shandong Lunan Rui-
387.53 0.0474 0.1362 367.77 0.4938 0.7954
hong instruments company), which was equipped with a flame
385.95 0.0744 0.2067 366.51 0.5341 0.8218
ionization detector (FID). The composition of vapor phase and liq-
384.15 0.1062 0.2825 364.99 0.5840 0.8526
uid phase was calculated by the area normalization method, which 382.96 0.1299 0.3357 363.60 0.6307 0.8768
381.80 0.1465 0.3750 362.17 0.6836 0.9015
can accurate to 0.001. The GC column was 30 m long and 0.32 mm
379.00 0.2023 0.4759 360.67 0.7333 0.9221
in diameter silica capillary column packed with OV-1701. The car-
376.05 0.2693 0.5731 359.27 0.7957 0.9448
rier gas was high purity nitrogen, and head pressure was 400 kPa.
374.00 0.3170 0.6373 357.16 0.9052 0.9775
The injector and detector temperature of column were 473.15 K 373.65 0.3255 0.6480 355.50 1 1
and 493.15 K, respectively.
2-propanol (1) + 1-pentanol (2)
Methanol + 2-propanol system as a checking system was mea-
411.10 0 0 380.36 0.3302 0.7905
sured first. The VLE data at 101.3 kPa and comparisons to literature 408.68 0.0156 0.0741 379.45 0.3494 0.8072
406.51 0.0315 0.1499 377.00 0.3956 0.8405
are shown in Fig. 1. The results matched very well with previous
404.91 0.0495 0.2355 374.75 0.4364 0.8644
literature and this result gives us a confidence of our instruments
402.10 0.0682 0.2973 372.45 0.4821 0.8861
and analysis method.
400.42 0.0854 0.3565 371.03 0.5105 0.8990
398.32 0.1016 0.4056 367.88 0.5908 0.9275
395.97 0.1250 0.4684 366.57 0.628 0.9385
3. Results and discussion
392.48 0.1615 0.5509 363.69 0.7059 0.9573
390.25 0.1895 0.6088 361.67 0.7645 0.9685
3.1. VLE model and experiment data 388.14 0.2141 0.6498 359.47 0.8324 0.9798
385.00 0.2579 0.7155 357.45 0.9032 0.9895
383.55 0.2794 0.7398 355.50 1 1
The VLE results of binary system (2-propanol + 1-butanol,
2-propanol + 1-pentanol, and 1-butanol + 1-pentanol) and ternary 1-butanol (1) + 1-pentanol (2)
411.10 0 0 400.17 0.4836 0.6405
system (2-propanol + 1-butanol + 1-pentanol) are shown in
410.00 0.0440 0.0741 398.60 0.5369 0.6895
Tables 2 and 3. The activity coefficient of pure component was
409.70 0.0537 0.0900 397.88 0.5796 0.7297
calculated by:
408.00 0.1046 0.1725 396.57 0.6488 0.7920
407.50 0.1383 0.2245 395.93 0.6913 0.8250