Quaternary, Ternary, and Binary LLE Measurements for 2-Methoxy-2

Article pubs.acs.org/jced

Quaternary, Ternary, and Binary LLE Measurements for 2‑Methoxy-2-methylpropane + Furfural + Acetic Acid + Water at Temperatures between 298 and 307 K Mikael Man̈ nistö, Juha-Pekka Pokki,* Hele Haapaniemi, and Ville Alopaeus Department of Biotechnology and Chemical Technology, Aalto University, P.O. Box 16100, FI-00076 Aalto, Finland ABSTRACT: In this paper, measured quaternary and ternary liquid−liquid equilibrium (LLE) data for 2-methoxy-2methylpropane (methyl tert-butyl ether, MTBE) + furfural + acetic acid (HAc) + water are presented. The measured data are presented together with the optimized binary interaction parameters for the utilized UNIQUAC-HOC (Hayden− O’Connell) activity coefficient model. Suitability of MTBE for liquid−liquid extraction of furfural in an industrial use is discussed.

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INTRODUCTION Usage of biomass in various forms has gained increasing interest in Finland as the pulp and paper industry is finding new uses for available raw materials. Xylose rich streams of a pulping process are attractive to convert xylose to furfural. Furfural is mainly produced through biomass treatment with steam and sulfuric acid1 as well as through hemicellulose hydrolysation processes as the main product.2 Furfural can also be obtained as a byproduct from fruit juice and wine production and storage.3 Uses of furfural range from extraction solvent for different lubricating oil manufacturing processes4 to a raw material for pharmaceuticals and phenolic resins as well as intermediate in many processes.3 Separation of furfural from aqueous mixtures is done through three main methods: distillation, adsorption, and liquid−liquid extraction. The use of distillation is hindered by the water− furfural azeotrope and high energy consumption, which make it financially challenging.5 Adsorption processes have also been studied by many authors; however, the possible challenges in desorption of furfural from adsorbents is less discussed.3,6−8 The most energy efficient choice at the moment therefore seems to be extraction using different solvents. To facilitate process development of extraction units, various types of data of furfural and its mixtures are needed. In addition to furfural, process streams of biorefinery contain acetic acid, formic acid, and levulinic acid.9 A considerable amount of work has been done to find the most suitable solvent for furfural extraction from aqueous solutions. Recently Pei et al.10 noted that the requirement for efficient recycling of the ionic-liquid is a challenge in their application for extraction. Alcohols like 2-methyl-2-butanol and 2-ethyl-1-hexanol have been studied by Cabezas et al.1 at 298 K. Croker and Bowrey11 studied methyl isobutyl ketone, toluene and isobutyl acetate as solvents for extraction of furfural from water. Our group has previously worked with 2-methyl-2butanol and methyl isobutyl ketone systems with water and furfural in the 298−401 K temperature range.12 The problem © XXXX American Chemical Society

with most of the studied alcohols is their high solubility into the aqueous phase and consequently the loss of solvent. Our aim was to study new solvents for extraction of furfural. In this work, the focus is on a tertiary ether traditionally blended in gasoline, MTBE, which is abundantly available in the market. Suitability of this component for furfural extraction has not been previously studied. MTBE has a very limited operating range in LLE extraction with regard to temperature due to its low normal boiling point (328.35 K), which on the other hand makes the separation of the solvent from the extract more efficient due to its high volatility. In this work, novel liquid−liquid data for the extraction of furfural is provided. Table 1. Used Chemicals and Their Reported and Measured GC Purities, in Wt %, and Refractive Indices, nD25, Measured at 101.3 kPaa chemical 2-methoxy-2methylpropane (MTBE) furfural furfural (distilled) acetic acid acetic acid (dried and distilled) deionized water analytical acetone

reported GC purity

measured GC purity

nD25 measured

nD25, ref 13

99.8+

99.85%

1.36594

1.3661

99

99.5% 99.9% 99.75% 99.91%

1.52263

1.52345 1.52345

1.33249 1.35553

1.3325 1.35596

99.8+

99.93%

a

Refractive indices measured in atmospheric pressure and room temperature, standard uncertainty (u) reported by the refractometer manufacturer u(nD) = 0.0005 and u(T/K) = 0.03. Determined uncertainties are u(w) = 0.05, u(p/kPa) = 2.7. Received: February 19, 2016 Accepted: June 7, 2016

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DOI: 10.1021/acs.jced.6b00149 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

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Article

EXPERIMENTAL SECTION Materials. All chemicals, except water and analytical acetone, were purchased from Sigma-Aldrich. Gas chromatography (GC) runs and refractive index measurements were carried out for all components to verify their purity. Analytical acetone, purchased from Merck, (CAS: 67-64-1) was used as an internal standard in the GC runs. Reported purity of MTBE (CAS: 1634-04-4) was 99.8%+. Acetic acid (CAS: 64-19-7) had a reported purity of 99.8%+ and was dried and distilled for the preparation of the standards to remove traces of water. Furfural (CAS: 98-01-1) had a reported purity of 99% and was distilled to obtain higher purity. Deionized water was prepared in-house using a Millipore Milli-Q system. Refractive indices were measured with a Dr. Kernchen Abbemat digital automatic refractometer. The reported purities, analyzed purities and refractive indices of all the compounds are shown in Table 1. Mixtures were prepared gravimetrically using a Precisa 410AM-FR analytical balance. It was calibrated by TEOPAL, certified by FINAS (Finnish Accreditation Service), with a reported uncertainty of u(m/g) = 0.002. Apparatus and Procedure. Liquid−liquid equilibrium (LLE) measurements for the quaternary and ternary systems were carried out between 298 and 307 K with a static glass apparatus presented in the earlier work.12 The solution was mixed for approximately 30 min after reaching the required temperature and allowed to settle for approximately 30 min after mixing. The method of mixing allowed for efficient mass transfer and phase dispersion. The settling time was adjusted according to both the density difference between the phases and visual identification of phase separation. The density difference of the phases made the separation fast when a clear

excess of one component was present. The density difference decreased as other components were added to the mixture, slowing down the settling of phases. However, due to adequate settling time, it was clear that all the bubbles from the phases had cleared and separation was complete at most 30 min after the mixing had stopped. Sampling from the apparatus was done using Hamilton sample-lock syringes. Binary systems of MTBE + water, ternary systems of MTBE + water + furfural and MTBE + water + acetic acid, as well as quaternary systems of MTBE + acetic acid + furfural + water were investigated with the glass cell apparatus between 298 and 307 K. There are four identical cells in the device, each approximately 25 mL. The original cell structure and the heating and mixing setups were presented in our earlier work.12 The sampling syringes and temperature correlations were used as in the previous work. The cells were modified for this work by adding a metal mesh mixer to compliment the earlier setup and to enhance mixing. The updated cell is presented in Figure 1. Contents of the equilibrium phases were analyzed with an Agilent Technologies 6890N gas chromatograph (GC) equipped with a quartz y splitter and two detectors and two columns (28m DBWaxETR connected to the thermal conductivity detector (TCD) and a 30 m HP-5 column connected to flame ionization detector (FID)). The setup of the GC was described in earlier work.12 Analysis of Samples. Gravimetric binary standards were prepared into 10 mL volumetric flasks using an analytical balance. The following binary mixtures were used in the prepared standards: furfural + water, furfural + MTBE, MTBE + water, HAc + water, HAc + furfural, and HAc + MTBE. Each of the systems were diluted with gravimetric amount of acetone as an internal standard. The mass fractions were calculated based on TCD peak areas because it can also detect water. The ratio of organic components in FID to TCD were used as a checking procedure as in earlier work.12 Response factors were calculated with eq 1 and their uncertainties with eq 2 ⎛ Astd ⎞⎛ mi ⎞ g μ V·s Fi = Fstd⎜⎜ A ⎟⎟⎜⎜ mstd ⎟⎟ i ⎝ μ V·s ⎠⎝ g ⎠

Figure 1. Example of a utilized glass cell with the updated mixers.

(1)

Table 2. Determined Response Factors, F, for the GC Detectorsa for MTBE + Furfural + Acetic Acid + Water Mixtures with Respect to Acetoneb FID component F (response factor)

MTBE 0.747

HAc 2.042

TCD furfural 0.929

MTBE 1.187

HAc 1.112

furfural 1.183

water 0.892

Thermal conductivity detector, TCD, and flame ionizing detector, FID. bStandard uncertainties (u) are u(MTBE, FID) = 0.014, u(HAc, FID) = 0.030, u(furfural, FID) = 0.016, u(MTBE, TCD) = 0.022, u(HAc, TCD) = 0.016, u(furfural, TCD) = 0.020, u(water, TCD) = 0.014. a

Table 3. Optimized UNIQUAC-HOC Binary Interaction Parameters for Components Used component i

MTBE

furfural

MTBE

furfural

water

component j

water

water

furfural

HAc

HAc

HAc

Aij Aji Bij Bji Cij Cji Dij Dji

−24.6080 3.0685 2717.7500 −101.6570 0 0 0.0450 −0.0097

−4.0277 0.0267 68.5197 108.2790 0 0 0.0106 −0.0024

0 0 −205.3133 41.8421 0 0 0 0

−1.5780 1.2100 689.7579 −644.5795 0 0 0 0

0.0462 5.3635 235.4490 −2413.0124 0 0 0 0

−2.3781 1.0391 −16.5162 −14.0740 0 0 0 0

B

MTBE



ΔFi =

Article

2 2 2 2 ⎛ ∂Fi ⎛ ∂Fi ⎛ ∂Fi ⎛ ∂Fi ΔAi ⎞ ΔA std ⎞ Δmbalance ⎞ Δmbalance ⎞ × × × × ⎟ +⎜ ⎟ ⎜ ⎟ +⎜ ⎟ +⎜ μ V·s ⎠ μ V·s ⎠ g g ⎝ ∂Ai ⎝ ∂A std ⎝ ∂mi ⎠ ⎝ ∂mstd ⎠

where Fstd denotes the “response factor” for the standard and was set to 1, Astd denotes peak area for acetone as the internal standard, Ai for component i, and mi and mstd the masses

weighed in grams for component i and the standard, respectively. The minor variation in response factors indicated them to be accurate. Uncertainties of the individual component areas in GC analysis for TCD were determined as in earlier work.12 Mass uncertainty was estimated to be three times the reported uncertainty of the analytical balance (in total 0.006 g) for the samples (three weighing of the syringe) and four times for the gravimetric standards (four weighing of the vial, in total 0.008 g). The highest uncertainty found for the response factors for TCD during the measurements was for furfural, u(furfural, TCD) = 0.020. Response factors for MTBE, furfural, HAc, and water along with their calculated uncertainties are reported in Table 2. Samples from the cells were taken by first weighing the clean Hamilton syringe, then drawing the sample from the cell, weighing the syringe, drawing the internal standard into the syringe and weighing the syringe again. Then the sample was injected into a 2 mL GC vial and closed with the aluminum crimp septa for analysis. The GC analysis method was kept the same as in the earlier work.12 Modeling of the Measured Data. Our measured liquid− liquid equilibria data as well as literature data for LLE,14−24 VLE,25−32 and additional azeotropic data33−37 were modeled using UNIQUAC-HOC where UNIQUAC38 is the activity coefficient model for the liquid phase and Hayden−O’Connell39 (HOC) is the fugacity coefficient model for the vapor phase. The HOC model takes into account the dimerization of organic acid in vapor phase. This modeling technique aims at a consistent and extrapolative model to describe the LLE and VLE phenomena in liquid−liquid extraction and distillation. Liquid−liquid equilibrium criteria at low to moderate pressure is defined in eq 3

Table 4. MTBE (1) + Water (2) Binary Measurements from Thermal Conductivity Detector Analysis as Mass Fractions, w, as a Function of Temperature, T, at Pressure p = 101 kPaa organic phase

aqueous phase

Tcell/K

w1

w2

w1

w2

298.3 298.3 298.3 307.9 307.9 307.8

0.986 0.987 0.986 0.986 0.986 0.984

0.014 0.013 0.014 0.014 0.014 0.016

0.041 0.041 0.042 0.032 0.031 0.032

0.959 0.959 0.958 0.968 0.969 0.968

a

Standard uncertainties (u) are u(T/K) = 0.2, u(w1, organic) = 0.001, u(w2, organic) = 0.003, u(w1, aqueous) = 0.008, u(w2, aqueous) = 0.002, and u(p/kPa) = 1.

Table 5. MTBE (1) + Furfural (2) + Water (3) Ternary Measurements from Thermal Conductivity Detector Analysis as Mass Fractions, w, as a Function of Temperature, T, at Pressure p = 101 kPaa organic phase

aqueous phase

Tcell/K

w1

w2

w3

w1

w2

w3

298.2 298.2 298.1 298.2 298.3 298.1 298.2 298.2 298.3 298.3 298.2 298.2 298.2 307.5 307.6 307.5 307.9 307.5 307.6 307.6 307.5 307.8 307.6 307.8 307.8 307.9

0.059 0.113 0.168 0.175 0.249 0.349 0.377 0.458 0.557 0.645 0.677 0.775 0.870 0.058 0.111 0.164 0.241 0.347 0.371 0.454 0.541 0.627 0.628 0.673 0.754 0.863

0.888 0.834 0.779 0.772 0.700 0.603 0.576 0.500 0.407 0.323 0.293 0.201 0.110 0.881 0.827 0.778 0.699 0.603 0.580 0.502 0.420 0.335 0.339 0.296 0.220 0.117

0.053 0.053 0.053 0.053 0.051 0.048 0.047 0.042 0.036 0.032 0.030 0.024 0.020 0.061 0.062 0.058 0.060 0.050 0.049 0.044 0.039 0.038 0.033 0.031 0.026 0.020

0.008 0.013 0.018 0.018 0.024 0.029 0.030 0.033 0.035 0.036 0.037 0.038 0.039 0.006 0.011 0.015 0.019 0.024 0.024 0.026 0.028 0.028 0.029 0.029 0.030 0.031

0.075 0.071 0.067 0.066 0.061 0.055 0.053 0.048 0.043 0.038 0.035 0.028 0.018 0.079 0.074 0.070 0.063 0.056 0.055 0.049 0.045 0.039 0.039 0.036 0.029 0.018

0.917 0.916 0.915 0.916 0.915 0.916 0.917 0.919 0.922 0.926 0.928 0.934 0.943 0.915 0.915 0.915 0.918 0.920 0.921 0.925 0.927 0.933 0.932 0.935 0.941 0.951

(2)

xi′γi′ = xi″γi″

(3)

Table 6. MTBE (1) + Acetic Acid (2) + Water (3) Ternary Measurements from Thermal Conductivity Detector Analysis as Mass Fractions, w, as a Function of Temperature, T, at Pressure p = 101 kPaa organic phase

a Standard uncertainties (u) are u(T/K) = 0.2, u(w1, organic) = 0.001, u(w2, organic) = 0.002, u(w3, organic) = 0.003, u(w1, aqueous) = 0.008, u(w2, aqueous) = 0.008, u(w3, aqueous) = 0.002, and u(p/kPa) = 1.

aqueous phase

Tcell/K

w1

w2

w3

w1

w2

w3

298.3 298.3 298.3 298.2 298.2 307.4 307.0 306.6 307.8 307.7 307.6

0.918 0.878 0.717 0.704 0.622 0.920 0.881 0.728 0.719 0.641 0.549

0.052 0.082 0.193 0.200 0.248 0.050 0.079 0.187 0.192 0.239 0.287

0.030 0.040 0.090 0.096 0.130 0.030 0.040 0.085 0.089 0.120 0.164

0.046 0.048 0.063 0.065 0.081 0.037 0.040 0.058 0.058 0.073 0.099

0.060 0.091 0.186 0.189 0.232 0.062 0.094 0.191 0.196 0.238 0.279

0.894 0.861 0.751 0.746 0.687 0.901 0.866 0.751 0.746 0.689 0.622

a Standard uncertainties (u) are u(T/K) = 0.2, u(w1, organic) = 0.002, u(w2, organic) = 0.004, u(w3, organic) = 0.005, u(w1, aqueous) = 0.005, u(w2, aqueous) = 0.004, u(w3, aqueous) = 0.002, and u(p/kPa) = 1.

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Table 7. MTBE (1) + Furfural (2) + Acetic Acid (3) + Water (4) Quaternary Measurements from Thermal Conductivity Detector Analysis as Mass Fractions, w, as a Function of Temperature, T, at Pressure p = 101 kPaa organic phase

aqueous phase

Tcell/K

w1

w2

w3

w4

w1

w2

w3

w4

298.2 298.2 298.2 298.2 298.2 298.2 298.3 298.2 298.4 298.2 298.2 298.2 298.2 298.2 298.4 307.7 307.7 307.7 307.6 307.6 307.8 307.8 307.8 307.5 307.7 307.8 307.7 307.7

0.329 0.417 0.419 0.438 0.519 0.520 0.528 0.543 0.573 0.586 0.639 0.650 0.671 0.712 0.713 0.317 0.337 0.425 0.432 0.450 0.523 0.528 0.539 0.553 0.587 0.649 0.675 0.720

0.235 0.162 0.271 0.141 0.247 0.177 0.145 0.135 0.190 0.259 0.206 0.256 0.178 0.203 0.182 0.132 0.236 0.271 0.162 0.142 0.248 0.178 0.147 0.136 0.260 0.257 0.178 0.178

0.219 0.234 0.168 0.237 0.130 0.179 0.195 0.194 0.137 0.082 0.087 0.043 0.087 0.041 0.056 0.270 0.216 0.165 0.229 0.233 0.128 0.175 0.190 0.190 0.081 0.042 0.085 0.054

0.217 0.187 0.142 0.184 0.104 0.124 0.132 0.128 0.100 0.073 0.068 0.051 0.064 0.044 0.049 0.281 0.211 0.139 0.177 0.175 0.101 0.119 0.124 0.121 0.072 0.052 0.062 0.048

0.088 0.087 0.059 0.088 0.051 0.061 0.065 0.067 0.053 0.043 0.046 0.040 0.045 0.042 0.042 0.146 0.084 0.055 0.083 0.083 0.045 0.056 0.060 0.060 0.032 0.028 0.039 0.035

0.091 0.058 0.066 0.052 0.048 0.044 0.040 0.037 0.040 0.041 0.035 0.036 0.032 0.030 0.029 0.083 0.095 0.069 0.060 0.053 0.051 0.046 0.042 0.039 0.069 0.037 0.032 0.030

0.200 0.211 0.149 0.216 0.115 0.158 0.175 0.175 0.123 0.074 0.080 0.040 0.081 0.039 0.053 0.260 0.204 0.153 0.215 0.219 0.118 0.163 0.180 0.179 0.897 0.933 0.084 0.055

0.621 0.644 0.726 0.644 0.786 0.737 0.720 0.721 0.784 0.842 0.839 0.884 0.842 0.889 0.876 0.511 0.617 0.723 0.642 0.645 0.786 0.735 0.718 0.722 0.002 0.002 0.845 0.880

a

Standard uncertainties (u) are u(T/K) = 0.2, u(w1, organic) = 0.003, u(w2, organic) = 0.003, u(w3, organic) = 0.003, u(w4, organic) = 0.004, u(w1, aqueous) = 0.006, u(w2, aqueous) = 0.004, u(w3, aqueous) = 0.003, u(w4, aqueous) = 0.002, and u(p/kPa) = 1.

Figure 2. Furfural mass fractions in extract and raffinate phase for MTBE (1) + furfural (2) + water (3) (left) and Othmer−Tobias plot (right) as calculated from data presented in Table 5: ◆, measured at 298 K; ○, measured at 307 K.

where y refers to vapor mole fraction, ϕ to vapor phase fugacity, p to system pressure, x to liquid mole fraction, γ to activity coefficient, psat i to vapor pressure of pure component, POY to the Poynting term, and the index “sat” refers to saturated state. HOC model affects the VLE and the activity coefficient through eq 5 and has an indirect effect on LLE through eq 3 as the UNIQUAC-HOC activity coefficient model calculates the equilibrium criteria of both the VLE and the LLE with the same set of parameters. The activity coefficient of UNIQUAC as a model is dependent only on liquid mole fraction, temperature, and model parameters (Aij, etc.) whatever the data type is.

where the prime and double prime refer to two liquid phases in equilibrium and subscript i denotes a component. The temperature dependence of UNIQUAC in Aspen takes in to account binary interaction parameters as shown in eq 4 2

τij = e A ij + (Bij /(T /K)) + Cij * ln(T /K) + Dij * (T /K) + (Eij /(T /K) )

(4)

The equilibrium criteria for vapor liquid equilibrium is defined by eq 5 yi ϕip = xiγipisat ϕisat POY

(5) D



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Figure 3. Acetic acid mass fractions in extract and raffinate phase for MTBE (1) + acetic acid (2) + water (3) (left) and Othmer−Tobias plot (right) as calculated from data presented in Table 6: ◆, measured at 298 K; ○, measured at 307 K.

Figure 4. Comparison of our measured MTBE (1) + water (2) binary data (Table 4) to literature data. Left figure represents the aqueous phase and right figure the organic phase. The line represents the model; ○, this work; *, literature data by Zikmundova et al.;14 +, literature data by Stephenson et al.;15 ▲, literature data by Alkandary et al.;16 □, literature data by Lei et al.18

Figure 5. Regressed models for MTBE (1) + furfural (2) + water (3) with UNIQUAC-HOC, shown with our measurements (Table 5): −, modeled; ◆, measured. Left figure shows the aqueous phase enlarged.

From the regression point of view, the activity coefficients in eq 3 can compensate (x′/x″ equals γ″/γ′) each other as they exist on both sides of the equation, but in eq 5, the activity coefficient exists only on one side and thus is bound by other variables. The regressed model applies not only to

liquid−liquid extraction but also to distillation of extract and raffinate. Parameter regression was accomplished with Aspen Plus 8.6. The binary interaction parameters were optimized based on binary and ternary mixtures of the components. The measured E



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Figure 6. Developed models for MTBE (1) + acetic acid (2) + water (3) with UNIQUAC-HOC, shown with our measurements (Table 6) and literature data: *, literature data by Miao et al.;24 −, modeled; ◆, measured.

Table 8. Calculated Distribution Coefficients, K, and Selectivities, S, of the Mixture MTBE (1) + Furfural (2) + Water (3) Presented with Measurement Temperature, T, and Furfural Mass Fraction, w, from the Data Presented in Table 5a

Table 9. Calculated Distribution Coefficients, K, and Selectivities, S, of the Mixture MTBE (1) + Acetic Acida (2) + Water (3) Presented with Measurement Temperature, T, and HAc Mass Fraction, w, from the Data Presented in Table 6b

Tcell/K

wfurfural,extract

wfurfural,raffinate

Kfurfural

Sfurfural

Tcell/K

wHAc,extract

wHAc,raffinate

KHAc

SHAc

298.2 298.2 298.1 298.2 298.3 298.1 298.2 298.2 298.3 298.3 298.2 298.2 298.2 307.5 307.6 307.5 307.9 307.5 307.6 307.6 307.5 307.8 307.6 307.8 307.8 307.9

0.888 0.833 0.779 0.772 0.700 0.603 0.576 0.499 0.406 0.323 0.293 0.201 0.110 0.881 0.827 0.778 0.699 0.603 0.580 0.502 0.420 0.335 0.339 0.296 0.220 0.117

0.075 0.071 0.067 0.066 0.061 0.055 0.053 0.048 0.043 0.038 0.035 0.028 0.018 0.079 0.074 0.070 0.063 0.056 0.055 0.049 0.045 0.039 0.039 0.036 0.029 0.019

11.87 11.80 11.65 11.71 11.42 11.00 10.93 10.32 9.40 8.60 8.37 7.21 6.06 11.16 11.22 11.11 11.11 10.75 10.63 10.17 9.35 8.65 8.74 8.33 7.46 6.29

205.75 202.23 200.32 204.03 206.69 210.38 214.92 223.58 238.69 251.96 263.80 275.08 294.25 167.13 166.59 176.48 170.48 196.27 200.92 213.92 222.52 214.08 249.65 252.90 266.51 297.15

298.3 298.3 298.3 298.2 298.2 307.4 307.0 306.6 307.8 307.7 307.6

0.052 0.083 0.193 0.200 0.248 0.050 0.080 0.187 0.192 0.239 0.287

0.060 0.091 0.186 0.189 0.232 0.062 0.094 0.191 0.196 0.238 0.279

0.86 0.91 1.04 1.05 1.07 0.80 0.85 0.98 0.98 1.00 1.03

25.58 19.83 8.65 8.20 5.68 24.05 18.55 8.68 8.14 5.75 3.90

a

HAc. bStandard uncertainties (u) are u(T/K) = 0.2, u(wfurfural,extract) = 0.004, u(wfurfural,aqueous) = 0.004.

systems were evaluated based on the regressed parameters in Aspen Plus 8.6. The regression was carried out with the maximumlikelihood objective for Britt−Luecke algorithm and the regressed UNIQUAC-HOC parameters are shown in Table 3. Some binaries required more parameters for appropriate data fitting and therefore the amount of parameters is not uniform across all component pairs. Pure component properties and other required parameters were retrieved with Aspen Plus from NIST ThermoData Engine database. Hayden−O’Connell parameters for MTBE were missing but set equal to parameters

a

Standard uncertainties (u) are u(T/K) = 0.2, u(wfurfural,extract) = 0.002, u(wfurfural,aqueous) = 0.008.

Figure 7. Distribution coefficient and selectivity for furfural as a function of furfural mass fraction in raffinate in the system MTBE (1) + furfural (2) + water (3): ◆, measured at 298 K; ○, measured at 308 K. F



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Figure 8. Distribution coefficient and selectivity for acetic acid as a function of acetic acid mass fraction in raffinate in the system MTBE (1) + acetic acid (2) + water (3): ◆, measured at 298 K; ○, measured at 308 K.

of diethyl-ether (CAS: 60-29-7) based on the similarity of their chemical structures.

Mass fraction of each component was calculated from the masses based on the peak areas using eq 7

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RESULTS AND DISCUSSION Masses for components in the sample were calculated based on the recorded GC peak areas and the response factors discussed earlier with eq 6

wi =

A

Fi* μ Vi·s m mi = * std A g Fstd* μ Vstd·s g

Δwi =

Δmi = g

mi g N mi ∑i = 1 g

(7)

where N is the total number of components. The uncertainty for each composition was determined with eq 8 and the uncertainty for each individual mass with eq 9

(6)

2 2 2 2 ⎛ ∂w ⎛ ∂wi ⎛ ∂wi ⎛ ∂wi Δmj ⎞ Δmz ⎞ Δmi ⎞ Δmk ⎞ i ⎟ +⎜ × × × × ⎟ ⎜ ⎟ + ⎜⎜ ⎟ +⎜ g ⎠ g ⎟⎠ g ⎠ g ⎠ ⎝ ∂mi ⎝ ∂mk ⎝ ∂mz ⎝ ∂mj

2 2 2 ⎛ ∂mi ⎛ ∂mi ⎛ ∂m ⎞2 ⎛ ∂mi ΔAi ⎞ ΔA std ⎞ Δmstd ⎞ × × × ⎟ ⎜ ⎟ +⎜ ⎟ + ⎜ i × ΔFi ⎟ + ⎜ μ V·s ⎠ μ V·s ⎠ g ⎠ ⎝ ∂Ai ⎝ ∂A std ⎝ ∂Fi ⎠ ⎝ ∂mstd

Measurement results for both furfural and acetic acid mixtures with MTBE and water are shown in Tables 4 to 7. Binary mixture data for MTBE (1) + water (2) are reported in Table 4. The ternary mixture data are available in Table 5 for MTBE (1) + furfural (2) + water (3) and in Table 6 for MTBE (1) + acetic acid (2) + water (3). The quaternary mixtures of MTBE (1) + furfural (2) + acetic acid (3) + water (4) are reported in in Table 7. Othmer−Tobias plot40 and a plot of furfural mass fraction in solvent phase as a function of furfural mass fraction in aqueous phase were used as additional indicators of the success of sampling. Points out of the trend (two points for the furfural ternary and no points for the acetic acid ternary) were rejected. Plots for MTBE (1) + furfural (2) + water (3) are available in Figure 2 and plots for MTBE (1) + acetic acid (2) + water (3) are available in Figure 3. Binary MTBE (1) + water (2) data are compared to available literature in Figure 4. The ternary systems of MTBE (1) + furfural (2)+ water (3) and MTBE (1) + acetic acid (2) + water (3) are presented in Figures 5 and 6. Our data agrees very well at both temperatures with the literature data. It can also be observed that the regressed model represents the data well without high discrepancies. The difference between the experimental points of our measurements

(8)

(9)

and literature data is small and is considered to be insignificant when observed graphically. Suitability of the solvent for industrial applications was analyzed using the distribution coefficient calculated with eq 10 and selectivity calculated with eq 11 wfurfural,extract K= wfurfural,raffinate (10) S=

wfurfural,extract wfurfural,raffinate

×

wwater,raffinate wwater,extract

(11)

Plots for the selectivity of furfural and acetic acid in the extraction as well as the distribution factors for MTBE (1) + furfural (2) + water (3) are presented in Table 8 and shown in Figure 7 and with MTBE (1) + acetic acid (2) + water (3) in Table 9 and Figure 8. The relatively high selectivity for furfural as well as the distribution coefficients between aqueous and organic phases seen in Figure 7 present MTBE as an interesting solvent for extraction processes. The distribution factor for acetic acid seen in Figure 8 does however bring up an issue−if the solvent is used in a stream containing both acetic acid and furfural, a process for acetic acid removal prior to furfural extraction G



Article

(9) Raman, J. K.; Gnansounou, E. Furfural production from empty fruit bunch − A biorefinery approach. Ind. Crops Prod. 2015, 69, 371− 377. (10) Pei, Y.; Wu, K.; Wang, J.; Fan, J. Recovery of Furfural from Aqueous Solution by Ionic Liquid Based Liquid−Liquid Extraction. Sep. Sci. Technol. 2008, 43, 2090−2102. (11) Croker, J. R.; Bowrey, R. G. Liquid extraction of furfural from aqueous solution. Ind. Eng. Chem. Fundam. 1984, 23, 480−484. (12) Männistö, M.; Pokki, J.; Creati, A.; Voisin, A.; Zaitseva, A.; Alopaeus, V. Ternary and Binary LLE Measurements for Solvent (4Methyl-2-pentanone and 2-Methyl-2-butanol) + Furfural + Water between 298 and 401 K. J. Chem. Eng. Data 2016, 61, 903−911. (13) Design Institute for Physical Properties DIPPR Project 801 (Full Version), 2014. http://aiche.org/dippr (accessed February, 2016). (14) Zikmundová, D.; Matouš, J.; Novák, J. P.; Kubíček, V.; Pick, J. Liquidliquid and vapourliquid equilibria in the system methyl tert-butyl ether + tetrahydrofuran + water. Fluid Phase Equilib. 1990, 54, 93−110. (15) Stephenson, R. M. Mutual solubilities: water-ketones, waterethers, and water-gasoline-alcohols. J. Chem. Eng. Data 1992, 37, 80− 95. (16) Alkandary, J. A.; Aljimaz, A. S.; Fandary, M. S.; Fahim, M. A. Liquid−liquid equilibria of water + MTBE + reformate. Fluid Phase Equilib. 2001, 187−188, 131−138. (17) Ashour, I. Liquid−Liquid Equilibrium of MTBE + Ethanol + Water and MTBE + 1-Hexanol + Water over the Temperature Range of 288.15 to 308.15 K. J. Chem. Eng. Data 2005, 50, 113−118. (18) Lei, Y.; Chen, Y.; Li, X.; Qian, Y.; Yang, S.; Yang, C. Liquid− Liquid Equilibria for the Ternary System 2-Methoxy-2-methylpropane + Phenol + Water. J. Chem. Eng. Data 2013, 58, 1874−1878. (19) Linek, J.; Bernatova, S. Liquid-Liquid Equilibria in the System Methanol-Water-Tert-Amyl Methyl Ether. Collect. Czech. Chem. Commun. 1986, 51, 188. (20) Arce, A.; Blanco, M.; Riveiro, R.; Vidal, I. Liquid-liquid equilibria of (MTBE or TAME) + ethanol + water mixtures. Can. J. Chem. Eng. 1996, 74, 419−422. (21) Liu, D.; Li, Q.; Chen, Z. Determination of mutual solubility data for four binary systems by the cloud point-equilibrium stillheterothermic methods. Tianranqi Huagong 1994, 19, 52−58. (22) Park, S. -J.; Hwang, I. -C.; Kwak, H. -Y. Binary Liquid−Liquid Equilibrium (LLE) for Dibutyl Ether (DBE) + Water from (288.15 to 318.15) K and Ternary LLE for Systems of DBE + C1 ∼ C4 Alcohols + Water at 298.15 K. J. Chem. Eng. Data 2008, 53, 2089−2094. (23) Stephenson, R. M. Mutual solubility of water and aldehydes. J. Chem. Eng. Data 1993, 38, 630−633. (24) Miao, X.; Zhang, H.; Wang, T.; He, M. Liquid−Liquid Equilibria of the Ternary System Water + Acetic Acid + Methyl tert-Butyl Ether. J. Chem. Eng. Data 2007, 52, 789−793. (25) Arich, G.; Tagliavini, G. Liquid-vapor equilibrium isotherms for the water-acetic acid system. Ric. Sci. 1958, 28, 2493. (26) Campbell, A. N.; Kartzmark, E. M.; Gieskes, J. M. T. M. Vapor− Liquid Equilibria, Densities, and Refractivities in the System Acetic Acid − Chloroform − Water at 25 °C. Can. J. Chem. 1963, 41, 407− 429. (27) Calvar, N.; Domínguez, A.; Tojo, J. Vapor−liquid equilibria for the quaternary reactive system ethyl acetate + ethanol + water + acetic acid and some of the constituent binary systems at 101.3 kPa. Fluid Phase Equilib. 2005, 235, 215−222. (28) Bernatová, S.; Aim, K.; Wichterle, I. Isothermal vapour−liquid equilibrium with chemical reaction in the quaternary water + methanol + acetic acid + methyl acetate system, and in five binary subsystems. Fluid Phase Equilib. 2006, 247, 96−101. (29) Luo, J.; Wu, S.; Sun, Y. Vapor-Liquid Equilibrium of Acetic Acid-Water System Under Magnetic Field. Tianjin Daxue Xuebao 2007, 40, 1300. (30) Ping, L.; Peng, Y.; Mao, J. Vapor-Liquid Equilibria of Acetic Acid-Water-N-Methylpyrrolidone System at 26.67 kPa. J. Chem. Eng. Chin. Univ 2011, 25, 554−558.

would be wise, as the data would suggest that acetic acid splits between both extract and raffinate phase equally.

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CONCLUSIONS New data were measured for the quaternary, ternary, and binary systems involving MTBE, furfural, water, and acetic acid. The systems have been modeled using UNIQUAC-HOC thermodynamic model. Literature data for both LLE and VLE along with measured LLE data were used in the model development. In aqueous phase, the model over predicts the amount of MTBE slightly, however in process design this means that the extraction equipment would perform better, that is, raffinate would contain less MTBE than calculated. On the basis of the measurements and models, it seems that MTBE can quite selectively extract furfural out of an aqueous furfural + water mixture. In addition to this, the amount of MTBE transferring into the raffinate stream is low. However, in a quaternary case including acetic acid, it seems that acetic acid is present in both phases. This reduces solvent losses in an industrial process and the boiling point difference of the solvent and furfural makes regeneration easy. These factors affect the economics of the separation process. Use of MTBE as an extraction solvent in furfural extraction seems like a feasible option.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: juha-pekka.pokki@aalto.fi. Author Contributions

M.M. and J.-P.P. contributed equally. The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Funding

The authors would like to acknowledge the Academy of Finland (Suomen Akatemia) for its financial support (decision number 253336). Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Cabezas, J. L.; Barcena, L. A.; Coca, J.; Cockrem, M. Extraction of furfural from aqueous solutions using alcohols. J. Chem. Eng. Data 1988, 33, 435−437. (2) Vila, C.; Santos, V.; Parajó, J. C. Recovery of lignin and furfural from acetic acid−water−HCl pulping liquors. Bioresour. Technol. 2003, 90, 339−344. (3) Sahu, A. K.; Srivastava, V. C.; Mall, I. D.; Lataye, D. H. Adsorption of Furfural from Aqueous Solution onto Activated Carbon: Kinetic, Equilibrium and Thermodynamic Study. Sep. Sci. Technol. 2008, 43, 1239−1259. (4) Coto, B.; van Grieken, R.; Peña, J. L.; Espada, J. J. A generalized model to predict the liquid−liquid equilibrium in the systems oils. Chem. Eng. Sci. 2006, 61, 8028−8039. (5) Lange, J.; van der Heide, E.; van Buijtenen, J.; Price, R. Furfural-A promising platform for lignocellulosic biofuels. ChemSusChem 2012, 5, 150−166. (6) Singh, S.; Srivastava, V. C.; Mall, I. D. Fixed-bed study for adsorptive removal of furfural by activated carbon. Colloids Surf., A 2009, 332, 50−56. (7) Gupta, P.; Nanoti, A.; Garg, M. O.; Goswami, A. N. The removal of furfural from water by adsorption with polymeric resins. Sep. Sci. Technol. 2001, 36, 2835−2844. (8) Sahu, A. K.; Mall, I. D.; Srivastava, V. C. Studies on the adsorption of furfural from aqueous solution onto low-cost bagasse fly ash. Chem. Eng. Commun. 2007, 195, 316−335. H



Article

(31) Komatsu, H.; Nakamura, M.; Yamashita, Y.; Hirai, C. VaporLiquid Equilibrium Data for Five Binary Systems of Methanol, tertButylalcohol, tert-Butylmethylether and Water, and Quaternary Reactive System Producing tert-Butylmethylether from Methanol and tert-Butylalcohol. Kagaku Kogaku Ronbunshu 1997, 23, 983−992. (32) Tsirlin, Y. A. Liquid-vapour equilibrium in the furfural - water system at reduced pressures. Zh. Fiz. Khim. 1962, 36, 1673. (33) Chang, T.; Shih, T. T. Development of an azeotropic distillation scheme for purification of tetrahydrofuran. Fluid Phase Equilib. 1989, 52, 161−168. (34) Evans, T. W.; Edlund, K. R. Tertiary Alkyl Ethers Preparation and Properties. Ind. Eng. Chem. 1936, 28, 1186−1188. (35) Komatsu, H.; Yamashita, Y.; Hirai, C.; Tanaka, T.; Hisaki, T. Vapor-Liquid Equilibrium Data for Four Ternary Systems Composed of Methanol, Tert-Butylalcohol, Tert-Butylmethylether and Water at Atmospheric Pressure, and Liquid-Liquid Equilibrium Data for Two Ternary Systems of Tert-Butylmethylether-Water-Methanol or TertButylalcohol at 303 K. Kagaku Kogaku Ronbunshu 1998, 24, 116−122. (36) Lesteva, T. M.; Kachalova, R. V.; Morozova, A. I.; Ogorodnikov, S. K.; Trenke, K. M. Study of Azeotropy in Binary and Ternary Systems. Zh. Prikl. Khim. 1967, 40, 1808−1814. (37) Zong, Z.; Yang, X.; Zheng, X. Determination of Phase Equilibria for Systems Containing Methyl tert-Butyl Ether. Ranliao Huaxue Xuebao 1987, 15, 32−41. (38) Abrams, D. S.; Prausnitz, J. M. Statistical thermodynamics of liquid mixtures: A new expression for the excess Gibbs energy of partly or completely miscible systems. AIChE J. 1975, 21, 116−128. (39) Hayden, J. G.; O’Connell, J. P. A Generalized Method for Predicting Second Virial Coefficients. Ind. Eng. Chem. Process Des. Dev. 1975, 14, 209−216. (40) Othmer, D. F.; Tobias, P. E. Liquid-Liquid Extraction Data The Line Correlation. Ind. Eng. Chem. 1942, 34, 693−696.

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Quaternary, Ternary, and Binary LLE Measurements for 2-Methoxy-2

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