Solvent for Liquid-Liquid Extraction Applications
Thomas Brouwer, and Boelo Schuur
ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/
acssuschemeng.0c04159 • Publication Date (Web): 31 Aug 2020
Downloaded from pubs.acs.org on September 16, 2020
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Dihydrolevoglucosenone (Cyrene™), a Bio-based
Solvent for Liquid-Liquid Extraction Applications
Thomas Brouwera and Boelo Schuura,*
aSustainable Process Technology group, Process and Catalysis Engineering cluster,
Faculty of Science and Technology, University of Twente, Dienerlolaan 5, Meander building, 7522 NB, Enschede, The Netherlands
*corresponding author: Meander building 221, 7522NB, Enschede, The Netherlands,
e: b.schuur@utwente.nl , p: +31 53 489 2891 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Abstract
Dihydrolevoglycosenone, commercially known as Cyrene™, is a versatile bio-based solvent reported for various applications including being a medium of chemical reactions and membrane manufacture. In this work, application of Cyrene™ in liquid-liquid extractions has been investigated. Four ternary systems have been assessed at 298.15K, 323.15K and 348.15K, keeping CyreneTM and methylcyclohexane constant and changing the third compound to toluene, cyclohexanol, cyclohexanone and cyclopentyl methyl ether. Studying these selected ternary systems, yielded an indication of applicability of Cyrene™ in related industrial separation processes such as aromatic/aliphatic separations, and in separations of oxygenates in the cyclohexane oxidation process. Key factors are biphasic system formation, distribution coefficients and selectivity. All ternary systems showed type I liquid-liquid phase behavior with a selective extraction of ternary components from methylcyclohexane by Cyrene™. The highest selectivity at 298.15K was found for cyclohexanol with 61.4±4.33, followed by cyclohexanone with 44.1±8.63, while toluene and cyclopentyl methyl ether had a selectivity of respectively 12.0±0.89 and 6.4±0.08. Although CyreneTM is applicable in 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
indicating a limited operation window for liquid-liquid extraction which will be more severe at higher temperatures. Overall, the studies showed that there are certainly application windows for Cyrene™. In the case of oxygenate extraction, a process with Cyrene™ appears energy-saving because the energy duty appears to be lower than when using water, the best alternative solvent, which is a low boiling solvent for this purpose.
KEYWORDS: Dihydrolevoglucosenone, CyreneTM, Bio-based Solvent, Liquid-Liquid Equilibrium, Liquid-Liquid Extraction
Introduction
Insights in the liquid-liquid extraction (LLX) applicability of dihydrolevoglycosenone, or Cyrene™, was obtained by performing LLX in four different ternary systems. CyreneTM, a bio-based polar solvent, attracted recent attention as being versatile for various applications, e.g. as a medium to perform chemical reactions1-7 and to prepare membranes by phase inversion8, though no mention for LLX applications has been found as of yet. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
CyreneTM can be an alternative aprotic dipolar solvent1, 8, solvents of this class are typically used in a range of molecular separations, from aromatic/aliphatic separation 9-11 to carboxylic acid separation from water.12 Industrially important members of the
solvent class of aprotic dipolar solvents include N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF), which both are considered toxic solvents and subject to restrictive legislation. 13-15 CyreneTM is reported to have a much lower toxicity16-17, and additionally since it is a biobased product, it offers chances for the chemical industry to reduce the consumption of fossil oil by replacing their toxic fossil oil-based solvents for a much more benign biobased alternative.18 In a recent communication, the Circa Group announced a production capacity of CyreneTM of 1 kton per annum, which signifies the mass production of this new biobased solvent.19 Although, bulk prices may not be publically available, Krishna et al. state that the bulk price of CyreneTM may be approximately to be 2 €/kg 20 which is comparable with traditional solvents.
Two key classes of molecular separation processes using solvents include extractive distillation (ED) and LLX. In another article21, we showed the potential of Cyrene™ as entrainer in ED of aromatic/aliphatic mixtures and paraffin/olefin mixtures. Similarly, 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
be useful for LLX as well. In order to investigate the applicability of Cyrene™ in LLX processes, we assessed the liquid-liquid equilibrium (LLE) behavior of several ternary systems formed with Cyrene™. The investigated systems include (1) methylcyclohexane (MCH) and toluene (TOL), (2) MCH and cyclohexanol (CHOH), (3) MCH and cyclohexanone (CHO) and (4) MCH and cyclopentyl methyl ether (CPME). The molecular structures of all species used in this study are displayed in figure 1.
OH O O O O O methylcylohexan e
toluene Cyclohexanol cyclohexanone Cyclopenthyl
methyl ether
Dihydrolevoglucose-none
(MCH) (TOL) (CHOH) (CHO) (CPME) (CyreneTM)
Figure 1. Structures of the molecules used in this study.
These ternary mixtures have specifically been chosen to firstly represent aromatics/aliphatics separations. These separations using LLX has been subject of study for a variety of model compounds, including benzene, toluene, xylenes, (methyl)cyclohexane and n-alkanes.22-27 The model systems vary as the related industrial mixture is complex.28 The results in this study on liquid-liquid equilibria with 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
CyreneTM, MCH and TOL will be compared to the elaborate work done in the past concerning molecular solvents22-24, ionic liquids (ILs)25, 29-30 and deep eutectic solvents (DESs).31-33
The separation of alcohols and ketones from aliphatics was chosen because the compounds possess either an alcohol or a ketone functionality, and they are relevant industrial chemicals, for example in the industrial oxidation process of cyclohexane to CHO and CHOH34-35. Kim et al. and Pei et al. investigated similar systems with CHO and CHOH, though used cyclohexane as hydrocarbon and studied dimethyl sulfoxide (DMSO) and water as a solvent.36-37
The last ternary mixture with MCH and CPME was chosen for the CPME ether functionality. CPME also has the potential of being a biobased solvent.38-40 The extraction of CPME from an aliphatic stream has not been studied yet.
Next to evaluation of the extraction performance of Cyrene™ for each of the systems, the LLE were also correlated using the UNIQUAC model. Lastly, by maintaining MCH as the constant, it became possible to compare all the systems with each other and investigate trends between different functional groups, and thus study the applicability 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Experimental Section Materials
Chemicals, if not otherwise specified, where used as received without any additional purification. Cyclopentyl methyl ether ( 99.9%), cyclohexanone ( 99.9%) and ≥ ≥ cyclohexanol (99%) were obtained from Sigma Aldrich, while methylcylohexane (Reagent Grade. 99%) was purchased from Honeywell. Toluene (ACS, reag.Ph.Eu) was procured from VWR Chemicals, while analytical acetone (LiChrosolv®) was acquired from Merck. A 1L bottle of dihydrolevoglucosenone, or CyreneTM, (99.3%) was supplied by the Circa Group.
Liquid-Liquid Extraction Procedure
For the liquid-liquid extraction experiments closed 10mL glass vials were used. All compounds were weighed with an accuracy of 0.5 mg on an analytical balance. Consecutively a vortex mixer and a temperature-controlled shaking bath were used in the equilibration. The mixture was shaken at 200 rpm for at least 12h at a constant temperature and subsequently settled for at least 1h prior to sample-taking. The experiments were conducted at 298.15K, 323.15K or 348.15K with a temperature variation of 0.02K. A solvent to feed ratio on mass basis of 1 was maintained and the 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
total mass of each phase was kept approximately at 3 grams. A sample of 0.5-1.0 mL was taken with a 2mL syringe with an injection needle from both phases. Both phases were analyzed following the analysis produce.
Analysis Procedure
A Thermo Scientific Trace 1300 gas chromatograph with two parallel ovens and an autosampler TriPlus for 100 liquid samples was used for the analyses. Each system was analyzed using an Agilent DB-1MS column (60m × 0.25mm × 0.25μm) with an injection volume of 1 μl diluted in analytical acetone. The same instrumental method was used for every system with a ramped temperature profile following the program of initial temperature at 50oC, followed by a direct ramp of 10 oC/min to 200oC. The second ramp, which was directly initiated after reaching 200oC, of 50 oC/min to 320 oC finished the program, which lasts 20 min. The FID temperature was 330oC. A column flow of 2 ml/min with a split ratio of 5, an airflow of 350 ml/min, a helium make-up flow of 40 ml/min and a hydrogen flow of 35 ml/min were used.
Fitting Procedure 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Each ternary system was correlated for all temperatures simultaneously with the UNIQUAC model. This model predicts the activity coefficient as the summation of the combinatorial ( and residual ( ) term of the activity coefficient, see equation 1.𝛾𝑐 41
𝑖) 𝛾𝑅𝑖
ln 𝛾𝑖= ln 𝛾𝑐𝑖 + ln 𝛾𝑅𝑖 (1)
The combinatorial term, using the Guggenheim-Stavermann approximation42, accounts for the influence of shape differences between the molecules and the corresponding entropy effects. This contribution of the activity coefficient is elaborated in equations 2, 3 and 4. ln 𝛾𝑐𝑖= ln
(
𝛷𝑖 𝑥𝑖)
+ 1 ― 𝛷𝑖 𝑥𝑖 ― 5𝑞𝑖(
ln(
𝛷𝑖 𝜃𝑖)
+ 1 ― 𝛷𝑖 𝜃𝑖)
(2) 𝛷𝑖= 𝑥𝑖𝑟𝑖 ∑ 𝑗𝑥𝑗𝑟𝑗 (3) 𝜃𝑖= 𝑥𝑖𝑞𝑖 ∑ 𝑗𝑥𝑗𝑞𝑗 (4)Where, is the volume fraction, is the surface area fraction, is the molar fraction 𝛷𝑖 𝜃𝑖 𝑥𝑖 and the Van der Waals volume, , and surface area, , of each component.𝑟𝑖 𝑞𝑖
The residual term, see equations 5 and 6, is determined using the same parameters, and the additional empirical binary interaction parameters . This value is fitted using 𝜏𝑖𝑗 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
the temperature independent parameter ( ) and temperature-dependent parameter (𝐴𝑖𝑗 ). 𝐵𝑖𝑗 ln 𝛾𝑅𝑖 = 𝑞𝑖
(
1 ― ln(
∑ 𝑗𝑞𝑗𝑥𝑗𝜏𝑗𝑖 ∑ 𝑗𝑞𝑗𝑥𝑗)
―∑
𝑗 𝑞𝑗𝑥𝑗𝜏𝑗𝑖 ∑ 𝑘𝑞𝑘𝑥𝑘𝜏𝑘𝑗)
(5) 𝜏𝑖𝑗= 𝐴𝑖𝑗+ 𝐵𝑖𝑗 𝑇(𝐾) (6)For the correlation, known Van der Waals volumes and surface areas were used, see table 1. For CyreneTM, the parameters were not available in the literature, and were estimated with Density Functional Theory with a B3LYP 6-311+G** parameterization in combination with the methodology of Banerjee et al.43
Table 1.Van der Waals volumes and surface areas of all components
Component ri qi Methylcyclohexane22 5.174 4.396 Toluene44 3.920 2.970 Cyclohexanol37 4.274 3.284 Cyclohexanone37 4.114 3.340 CPME45 4.214 3.248 CyreneTM 4.843 3.322
Results and Discussion
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
The four ternary LLE systems that were investigated in this study are presented in a subsection for each of the systems. All of the systems showed type I phase behavior46 for all temperatures investigated. For each of the ternary systems the selectivity ( ) 𝑆𝑖𝑗 of the solute (i), being toluene, cyclohexanol, cyclohexanone or CPME, over MCH (j) was examined (equation 8). This selectivity is defined as the ratio of the distribution coefficients (𝐾𝐷,𝑖) of each of the solutes, which in turn is defined as the ratio of the concentration of the solute, on a weight basis, in the solvent ([𝑋𝑖]𝑆) and the organic phase ([𝑋𝑖]𝑂) as in equation 7. 𝐾𝐷,𝑖= [𝑋𝑖]𝑆 [𝑋𝑖]𝑂 (7) 𝑆𝑖𝑗= 𝐾𝐷,𝑖 𝐾𝐷,𝑗 (8)
All experimental results have been correlated using the UNIQUAC model, which was checked on its thermodynamic consistency using the Hessian Matrix test. This information is provided in the Supporting Information(SI),47-48 as well as tables with all the measured data and calculated distribution coefficients and selectivities. This allows an approximate description of the binodal curve and the tielines. After describing the results for each of the ternary systems individually, in the last subsection, all ternary systems are compared to enable a general description of the affinities of CyreneTM 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
towards different moieties. Additionally, rough short-cut calculations were performed of the combined CHOH/MCH and CHO/MCH cases to assess the potential of CyreneTM in a LLX process. In the SI, all the weight fractions, distribution coefficients and selectivities of the ternary diagrams are displayed and/or tableted.
Methylcyclohexane – Toluene - CyreneTM
The results for the MCH – toluene – Cyrene™ ternary system are displayed in figure 2. As can be seen from the binodal curves, a significant miscibility region can be seen. For 298.15K, only below ~35 wt. % toluene a biphasic system is observed, which further reduces with increasing temperatures. This is in line with our work on extractive distillation at a temperature above 373K, where no phase splitting was observed for this system.21 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Figure 2. The ternary diagrams of the LLE of toluene, MCH and CyreneTM with the lie-lines, feed compositions and binodal curves at (a) 298.15K, (b) 323.15K and (c) 348.15K, and (d) the STOL,MCH of CyreneTM at the same temperatures. The UNIQUAC fit is added throughout.
A selectivity of 11.99±0.89 was induced with a toluene concentration of ~0.74 wt. % in the CyreneTM phase at 298.15K. This selectivity decreases to 6.76±0.65 and 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
4.91±0.58 at respectively 353.15K and 348.15K for similar toluene concentrations. This is due to a lower activity coefficient of MCH in CyreneTM, a consequence of a polarity decrease of the solvent phase, which is a consequence of the higher hydrocarbon (MCH and TOL) solubility at elevated temperatures which in turn is caused by the larger entropic contribution at higher temperatures. The correlated UNIQUAC parameters are given in table 2.
Table 2. Correlated UNIQUAC parameter for the MCH-toluene-CyreneTM system
Component i Component j Aij Aji Bij Bji Toluene 0 0 -191,0 171, 5 MCH 4,58 7 -2,627 -1749 773, 7 Toluene CyreneTM 2,70 8 -4,999 -772,6 1463
The LLX performance of CyreneTM has been put in perspective by the comparison with other solvents, such as SulfolaneTM, n-formylmorpholine26, methanol27 and various ILs, EMIM][ESO4]49, [HMIM][B(CN)4]50, [BMIM][B(CN)4]50 and [BMIM][MSO4]51.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
As can be seen in figure 3, SulfolaneTM is outperforming CyreneTM regarding selectivity and n-formylmorpholine26 has a higher selectivity at high toluene fractions in the solvent phase. Also, both solvents have a more significant phase split than CyreneTM. Comparable performance was seen towards methanol,27 though CyreneTM
has a more significant phase split.
Figure 3. (left) A comparison of (left) the LLE and (right) STOL,MCH at 298.15K of several
solvents; CyreneTM, SulfolaneTM, n-formylmorpholine26, methanol27, [EMIM][ESO4]49, [HMIM][B(CN)4]*50, [BMIM][B(CN)4]*50 and [BMIM][MSO4]51. *These systems were measured at 293.15K.
The ILs induce an almost complete immiscibility, due to lower distribution coefficients compared to traditional solvents. This immiscibility is due to their ionic nature, which 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
does not allow to stabilize in the highly apolar hydrocarbon mixture. Additionally, for low toluene fractions in the solvent phase, a similar selectivity towards toluene is observed for the ILs compared to SulfolaneTM. Although, at higher toluene fraction the tetracyanoborate ILs50 are able to retain a higher selectivity compared to SulfolaneTM. A consequence of lower distribution coefficients in ILs is however that a larger solvent quantity is required for the LLX, and the equipment diameter will increase. On the other hand, due to the larger selectivity, less stages are required, reducing the equipment height. Higher selectivity means that less aliphatics need to be boiled from the solvent in the solvent regeneration, which is beneficial for the energy requirement, which seems to be in favor for ILs. Overall, it is not straight forward to decide which solvent is better and a more thorough process simulation including total annual cost estimation is suggested but outside the scope of this paper.
Methylcyclohexane – Cyclopentyl methyl ether - CyreneTM
As can be seen in figure 4, CyreneTM induces a selectivity of 6.42±0.08, 4.55±0.41 and 3.91±0.31 at respectively 298.15K, 323.15K and 348.15K for ~0.65 wt. % of CPME 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Figure 4. The ternary diagrams of the LLE of CPME, MCH and CyreneTM with the lie-lines, feed compositions and binodal curves at (a) 298.15K, (b) 323.15K and (c) 348.15K, and (d) the SCPME,MCH of CyreneTM at the same temperatures. The UNIQUAC fit is added throughout.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The results indicate that CyreneTM is selective towards the polar ether moiety over the aliphatic MCH. A substantial miscibility region at CPME contents over ~35 wt. % CPME is observed, which resembles LLX-application window of the MCH-toluene case. In table 3, the UNIQUAC parameters of the correlation are displayed. This indicates that the dipolar characteristics of the ether moiety induces similar intermolecular interactions as the delocalized π-system of toluene.
Table 3. Correlated UNIQUAC parameter for the MCH-CPME-CyreneTM system
Component i Component j Aij Aji Bij Bji CPME 0 0 -61,53 19,2 1 MCH 3,33 2 -2,020 -1356 588, 3 CPME CyreneTM 2,31 9 -3,522 -661,0 899, 1
Methylcyclohexane – Cyclohexanol - CyreneTM
The results for the system MCH – CHOH – Cyrene™ are given in figure 5. CyreneTM induces a selectivity of 61.42±4.33, 32.8±5.83 and 16.6±2.26 at respectively 298.15K, 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
323.15K and 348.15K at ~0.80 wt. % of CHOH in the solvent phase. This is lower than observed with DMSO36 and water37, which have a selectivity of resp. 155 and 1450, at low CHOH concentrations.
The lower selectivity of CyreneTM can mainly be attributed to the larger hydrocarbon backbone of CyreneTM, compared to the small DMSO and water molecules, which mitigates the multipole interactions with the relatively unselective London dispersion interactions.52
Also in the ternary system MCH – CHOH – Cyrene™ a large miscibility region is observed, for concentrations above ~25 wt. % cyclohexanol. Due to the large miscibility in the system, only a small operation window is available for LLX, and the two phase region decreases at increasing temperature. The larger miscibility region indicates also that the capacity of CyreneTM (𝐾 = 4.64 at ~0.80 wt. % of CHOH in the solvent
𝐷,𝐶𝐻𝑂𝐻
phase) for CHOH is larger than water (𝐾 = 1.60Ɨ,37). 𝐷,𝐶𝐻𝑂𝐻 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Figure 5. The ternary diagrams of the LLE of cyclohexanol, MCH and CyreneTM with the lie-lines, feed compositions and binodal curves at (a) 298.15K, (b) 323.15K and (c) 348.15K, and (d) the SCPME,MCH of CyreneTM at the same temperatures. The UNIQUAC fit is added throughout.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
CyreneTM would be preferred when high CHOH capacities are required, while water is preferred when a larger immiscibility and selectivity is required. DMSO has been shown to be quite toxic53 and is for that reason not the preferred choice. The UNIQUAC parameters for this system are present in table 4.
Table 4. Correlated UNIQUAC parameter for the MCH-cyclohexanol-CyreneTM system
Component i Component j Aij Aji Bij Bji Cyclohexano l -0,1112 -0,1675 -435,6 239, 5 MCH 1,738 -0,7045 -817,2 153, 3 Cyclohexan ol CyreneTM 0 0 -128,7 12,0 5
Methylcyclohexane – Cyclohexanone - CyreneTM
The results for the ternary system MCH – CHO – Cyrene™ are given in figure 6. CyreneTM induces a selectivity of 44.07±8.63, 32.14±2.78 and 19.25±2.00 at respectively 298.15K, 323.15K and 348.15K for the lowest amount of CHO in the solvent phase (~0.60 wt. %). Also in this case, the selectivity is lower than reported for DMSO36 and water37, which have been reported to be 42.9 and 1202. Also in this case, 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
a significant miscibility region is observed at CHO contents higher than ~23 wt. %. The single phase region is larger than compared to the previous systems, indicating a narrower LLX application window. This is due to the mutual presence of ketone functionality in CHO and CyreneTM resulting in a significant mutual solubility. Hence CyreneTM has a larger capacity for CHO (𝐾 = 4.47 at ~0.60 wt. % of CHO in the
𝐷,𝐶𝐻𝑂
solvent phase) than water (𝐾 = 2.79Ɨ,37). Also for this case, CyreneTM and water 𝐷,𝐶𝐻𝑂
may be preferred solvent choices, if either CHO capacity or immiscibly window and selectivity are the selection criteria. As previously mentioned, DMSO is toxic and is preferentially avoided. In table 5, the UNIQUAC parameters of the correlation are displayed. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Figure 6. The ternary diagrams of the LLE of cyclohexanone, MCH and CyreneTM with the lie-lines, feed compositions and binodal curves at (a) 298.15K, (b) 323.15K and (c) 348.15K, and (d) the SCPME,MCH of CyreneTM at the same temperatures. The UNIQUAC fit is added throughout.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Table 5. Correlated UNIQUAC parameter for the MCH-cyclohexanone-CyreneTM system Component i Component j Aij Aji Bij Bji Cyclohexanon e -1,090 -1,090 364,9 364, 9 MCH 4,587 -2,627 -1749 773, 7 Cyclohexanon e CyreneTM 2,507 -7,521 -531,6 2133 Comparative Study
By considering the combined data from all ternary systems with toluene (TOL), cyclohexanol (CHOH), cyclohexanone (CHO) and CPME, from MCH, the performance of CyreneTM towards particular moieties can be evaluated. CyreneTM is a bi-cyclic organic molecule in which a double ether moiety, one in each ring, and a ketone functionality is present. All moieties are aprotic and therefore can only act as a hydrogen bond acceptor and will induce next to the omnipresent London dispersion interactions also Keesom and Debye interactions.52 Comparing the results, see table 6 and from the figures 2, 4, 5 and 6, it is concluded that selectivity order is found to be 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
CHOH, likely due to intra- and intermolecular hydrogen bonding, resulting in lower selectivity than CHO at higher temperatures.
Table 6. A comparison between the distribution coefficient and selectivity found for
CHOH, CHO, TOL and CPME at similar low weight percentage in the solvent phase at 298.15K, 323.15K and 348.15K Component j in solvent phase (wt.%) Distribution Coefficient component j (-) Selectivity (-) Component i Component j (298.15K / 323.15K / 348.15K ) CHOH 0.80 / 0.65 / 0.51 4.64 / 2.94 / 1.64 61.4 / 32.8 / 16.6 CHO 0.87 / 0.60 / 0.56 4.47 / 3.15 / 2.20 44.1 / 32.1 / 19.3 TOL 0.74 / 0.82 / 0.72 0.98 / 0.54 / 0.51 12.0 / 5.80 / 5.32 MCH CPME 0.83 / 0.63 / 0.57 0.30 / 0.40 / 0.40 5.15 / 4.27 / 3.54
CHOH and CHO are extracted with significantly higher selectivity than toluene and CPME. This is due to respectively the hydrogen bond donating character of CHOH and the significant dipole moment of 2.75D54 of CHO which induces substantial Keesom and Debye interactions with CyreneTM. Toluene and CPME do not have hydrogen bonding donating capabilities and have much lower dipole moments compared to 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
CHO, respectively 0.37D55 and 1.27D56, hence a lower selectivity is induced. Toluene does however exhibit a significant quadrupole moment,57 which is responsible for more extensive Keesom and Debye interactions and therefore a larger selectivity is induced compared to CPME.
When the CHO and CHOH cases are combined and their extraction performances are compared, a measure of selectivity towards both solutes may be estimated for the lowest weight fractions of solute in the solvent phase. A selectivity ratio (SCHOH,MCH/
SCHO,MCH) of 1.42 and 1.2137 is obtained for resp. CyreneTM and water. We speculate
that CyreneTM is a slightly more selective solvent for the combined extraction of CHO and CHOH than water, though this may be caused by the different alkane used in both studies. A CyreneTM-based LLX process for this separation was further investigated by short-cut energy calculations in the next section.
Process Considerations
Liquid-Liquid Equilibria are cornerstones in an accurate description of Liquid-Liquid Extractions (LLX) that arguably form the heart of LLX processes. As solvents are rarely 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
to recover the solvent and obtain a pure product. An example is given by an de Graff et al.58 where two distillation columns are used to recover the solvent and pure products from a LLX column. The raffinate can also be distilled to recovery the solvent, though for polar solvents the use of a water wash column to recover the solvent can be applied to save energy. Subsequently, the water is then evaporated from the solvent-rich water phase and the vapor is used to strip extracted solutes from the extract stream.59-61 To thoroughly compare Cyrene™ with all conventional solvents for all studied applications will require rigorous process simulations for all these process steps, and even consideration on which of the steps are required and preferred. This is beyond the scope of this paper, in which the applicability of Cyrene™ is explored and a first indication of the usefulness of the application is discussed on the basis of miscibility , distribution coefficients and selectivity. On the basis of a short-cut calculation an estimation of the required heat duty will be given for the combined case of MCH/CHO and MCH/CHOH. This case was chosen as being most interesting for industrial application in the industrial oxidation process of cyclohexane to CHO and CHOH34-35. The MCH-TOL case which certainly is also of industrial interest was not simulated because on the basis of the liquid-liquid equilibrium data it can be seen that both 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Sulfolane and ILs are clearly superior over Cyrene™ with regard to selectivity and immiscibility.
The most significant difference between water and CyreneTM is related to the recovery of the CHO and CHOH from the solvent, which boil at resp. 429K and 433K. CyreneTM is a high-boiling solvent (bp: 500K8), whereas water is a low-boiling solvent (bp: 373K). Recovery of water thus implies that the solvent has to be boiled off from the solutes, whereas the solutes can be boiled off from the Cyrene™. CyreneTM has therefore a significant advantage over water, due to the fact the energy-penalty associated with the evaporation enthalpy of the solvent is avoided in using the high-boiling CyreneTM. Also, the capacity of CHO and CHOH in water is lower compared to CyreneTM. This entails a larger amount of water is required to extract a certain amount of CHO and/or CHOH than CyreneTM.
In order to estimate the magnitude of the energy advantage, a set of rough calculations on the heat duty in the recovery processes were performed. Using the LLE description by UNIQUAC, the minimum solvent to feed (S:F) ratio (on mass basis) was determined by simulation in ASPEN Plus of the LLX process with 1000 equilibrium 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Afterwards, for the heat duty in the solvent recovery stage, a short-cut calculation was applied. Assuming that most of the sensible heat may be recoverable using heat exchangers, the latent heat of vaporization (ΔHvap) of the most volatile compound was used as estimate. For water as solvent, a minimum S:F ratio of 1.8 was obtained for CHOH and 7.3 for CHO. Since water for these systems is a volatile solvent, evaporation of all the water resulted in a heat duty of 41.3 MJ/kgCHOH and 166 MJ/kgCHO.
For CyreneTM, a lower minimum S:F ratio was required which is a direct consequence from the larger capacity towards CHO and CHOH, being 1.2 for CHOH and CHO. Furthermore, since Cyrene™ in these systems is a high boiling solvent, the solutes CHOH and CHO should be boiled off. Due to solvent leaching, MCH should be boiled off from the raffinate to recover the solvent, and the evaporation of MCH from the raffinate is included in the calculations. This resulted for CHOH in a heat duty of 3.86 MJ/kgCHOH and for CHO in 3.87 MJ/kgCHO. These short-cut calculations show that extraction processes using CyreneTM instead of water may be 11 times more efficient for the separation of CHOH from MCH and 43 times more efficient for CHO from MCH. This is a rough heat duty estimate, and in an accurate process simulation, the final 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
heat duty may be less beneficial. However, with the current figures, it shows high potential for a significant advantage of the high boiling CyreneTM over the low boiling water. The fact that most energy savings compared to water were accomplished by the higher boiling point of the solvent, suggests that for this application the use of ionic liquids (ILs) might be interesting too, on the condition that beneficial behavior is observed in LLE. However, no LLE data has been found for MCH/CHOH or CHO with an IL.
The separation of CHO and CHOH may also be accomplished with CyreneTM due to the fact a larger selectivity is observed toward CHOH than CHO. Although no phase separation is expected and LLX is not possible, other separation techniques may be used such as extractive distillation or perhaps with a extractive divided wall configuration.
Conclusion
Four biphasic ternary systems have been assessed in which methylcyclohexane (MCH) and CyreneTM were kept constant. As third compound toluene, cyclohexanol, 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
system a selective extraction was found at the three studied temperatures of 298.15K, 323.15K and 348.15K. Cyclohexanol (up to SCHOH,MCH = 61.42±4.33) and cyclohexanone (up to SCHO,MCH = 44.07±8.63) were most selectively extracted, while toluene (up to STOL,MCH = 11.99±0.89) and CPME (up to SCPME,MCH = 6.42±0.08) were extracted with considerably lower selectivity. While CyreneTM was outperformed by SulfolaneTM and several ionic liquids in the extraction of toluene, the potential of CyreneTM in the cyclohexanol/cyclohexanone systems was observed. Although a lower selectivity was seen than with water, due to the high boiling point of Cyrene™, recovery can be much less costly. Overall, we conclude that CyreneTM can be applied as biobased extraction solvent for a variety of separations, although for several systems the phase envelop is relatively narrow and narrower at higher temperatures.
Author Information
Boelo Schuur*
Sustainable Process Technology group, Process and Catalysis Engineering cluster, Faculty of Science and Technology, University of Twente. The Netherlands
Meander building 221, PO Box 217, 7500 AE, Enschede, The Netherlands, 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Email: b.schuur@utwente.nl , Phone: +31 53 489 2891 ORCID: 0000-0001-5169-4311
Thomas Brouwer
Sustainable Process Technology group, Process and Catalysis Engineering cluster, Faculty of Science and Technology, University of Twente. The Netherlands
Meander building 221, PO Box 217, 7500 AE, Enschede, The Netherlands, ORCID: 0000-0002-3975-4710
Acknowledgments
This has been an ISPT (Institute for Sustainable Process Technology) project (TEEI314006/BL-20-07), co-funded by the Topsector Energy by the Dutch Ministry of Economic Affairs and Climate Policy. We would like to acknowledge the Circa group for sending us 1L of Cyrene™ to perform this research.
Supporting Information
Electronic Supporting Information is available online, and contains four tables with 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
compounds in each phase, the distribution coefficient of MCH and the solute (being TOL, CHO, CHOH or CPME), and the selectivity of that solute over MCH. The thermodynamic consistency of all UNIQUAC correlations was checked using the determinant of the Hessian matrix approach,47-48 and the results displayed in four figures.
Abbreviations
[BMIM][B(CN)4] - 1-butyl-3-methylimidazolium tetracyanoborate [BMIM][MSO4] - 1-butyl-3-methylimidazolium methylsulfate [EMIM][ESO4] - 1-ethyl-3-methylimidazolium ethylsulfate [HMIM][B(CN)4] - 1-hexyl-3-methylimidazolium tetracyanoborate [Xi]O - Weight Fraction of compound i in the organic phase [Xi]S - Weight Fraction of compound i in the solvent phase
Aij - Temperature independent UNIQUAC fit parameter
Bij - Temperature dependent UNIQUAC fit parameter
Bp - boiling point
CHO - Cyclohexanone
CHOH - Cyclohexanol
CPME - Cyclopentyl methyl ether
CyreneTM - Dihydrolevoglycosenone D - Debye 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
DMF - N,N-dimethylformamide
DMSO - Dimethylsulfoxide
ED - Extractive Distillation
KD,i - Distributation coefficient of solute i
LLE - Liquid-liquid equilibrium
LLX - Liquid-liquid extraction
MCH - Methylcyclohexane
NMP - N-methylpyrrolidone
qi - Van der Waals surface area of solute i
ri - Van der Waals volume of solute i
Sij - Selectivity of solute i over solute j
SulfolaneTM - Tetrahydrothiophene-1,1-dioxide
SI - Supporting Information
S:F ratio - Solvent to Feed ratio (mass basis)
T(K) - Absolute temperature
TOL - Toluene
UNIQUAC - Universal Quasichemical
- Activity Coefficient of solute i 𝑦𝑖
- Combinatorial term of the activity Coefficient of solute i 𝑦𝑐𝑖
- Residual term of activity Coefficient of solute i 𝑦𝑅𝑖
- volume fraction 𝛷𝑖
- surface area fraction 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
- binary interaction parameter between solutes i and j 𝜏𝑖𝑗
Ɨ - Extrapolated from corresponding literature to similar solute
concentration in solvent phase.
References
1. Sherwood, J.; Constantinou, A.; Moity, L.; McElroy, C. R.; Farmer, T. J.; Duncan, T.; Raverty, W.; Hunt, A. J.; Clark, J. H., Dihydrolevoglucosenone (Cyrene) as a bio-based alternative for dipolar aprotic solvents. Chem. Commun. 2014, 50
(68), 9650-9652. https://doi.org/10.1039/C4CC04133J
2. Camp, J. E., Bio‐available Solvent Cyrene: Synthesis, Derivatization, and Applications. ChemSusChem 2018, 11 (18), 3048-3055.
https://doi.org/10.1002/cssc.201801420
3. Wilson, K. L.; Kennedy, A. R.; Murray, J.; Greatrex, B.; Jamieson, C.; Watson, A. J., Scope and limitations of a DMF bio-alternative within Sonogashira
cross-coupling and Cacchi-type annulation. Beilstein J. Org. Chem. 2016, 12 (1), 2005-2011. https://doi.org/10.3762/bjoc.12.187
4. Wilson, K. L.; Murray, J.; Jamieson, C.; Watson, A. J., Cyrene as a Bio-Based Solvent for the Suzuki–Miyaura Cross-Coupling. Synlett 2018, 29 (05), 650-654. DOI:
10.1055/s-0036-1589143
5. Wilson, K. L.; Murray, J.; Jamieson, C.; Watson, A. J., Cyrene as a bio-based solvent for HATU mediated amide coupling. Org. Biomol. Chem. 2018, 16 (16), 2851-2854. https://doi.org/10.1039/C8OB00653A
6. Mistry, L.; Mapesa, K.; Bousfield, T. W.; Camp, J. E., Synthesis of ureas in the bio-alternative solvent Cyrene. Green Chem. 2017, 19 (9), 2123-2128.
https://doi.org/10.1039/C7GC00908A
7. Zhang, J.; White, G. B.; Ryan, M. D.; Hunt, A. J.; Katz, M. J.,
Dihydrolevoglucosenone (Cyrene) as a green alternative to N, N-dimethylformamide (DMF) in MOF synthesis. ACS Sustain. Chem. Eng. 2016, 4 (12), 7186-7192.
https://doi.org/10.1021/acssuschemeng.6b02115
8. Marino, T.; Galiano, F.; Molino, A.; Figoli, A., New frontiers in sustainable membrane preparation: Cyrene™ as green bioderived solvent. J. Membr. Sci. 2019,
580, 224-234. https://doi.org/10.1016/j.memsci.2019.03.034 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
9. Choi, Y. J.; Cho, K. W.; Cho, B. W.; Yeo, Y.-K., Optimization of the sulfolane extraction plant based on modeling and simulation. Ind. Eng. Chem. Res. 2002, 41
(22), 5504-5509. https://doi.org/10.1016/S1474-6670(17)33881-8
10. Wang, Q.; Chen, J. Y.; Pan, M.; He, C.; He, C. C.; Zhang, B. J.; Chen, Q. L., A new sulfolane aromatic extractive distillation process and optimization for better energy utilization. Chem. Eng. Process. 2018, 128, 80-95.
https://doi.org/10.1016/j.cep.2018.04.011
11. Blahušiak, M.; Kiss, A. A.; Babic, K.; Kersten, S. R.; Bargeman, G.; Schuur, B., Insights into the selection and design of fluid separation processes. Sep. Purif.
Technol. 2018, 194, 301-318. https://doi.org/10.1016/j.seppur.2017.10.026
12. Reyhanitash, E.; Brouwer, T.; Kersten, S. R. A.; van der Ham, A. G. J.; Schuur, B., Liquid–liquid extraction-based process concepts for recovery of carboxylic acids from aqueous streams evaluated for dilute streams. Chem. Eng. Res. Des. 2018, 137, 510-533. https://doi.org/10.1016/j.cherd.2018.07.038
13. Lee, K.; Chromey, N.; Culik, R.; Barnes, J.; Schneider, P., Toxicity of
N-methyl-2-pyrrolidone (NMP): teratogenic, subchronic, and two-year inhalation studies.
Fund. Appl. Toxicol. 1987, 9 (2), 222-235. https://doi.org/10.1016/0272-0590(87)90045-5
14. Bergkamp, L.; Herbatschek, N., Regulating chemical substances under REACH: the choice between authorization and restriction and the case of dipolar aprotic solvents. Review of European, Comparative & International Environmental
Law 2014, 23 (2), 221-245. https://doi.org/10.1111/reel.12083
15. Sherwood, J.; Farmer, T. J.; Clark, J. H., Catalyst: Possible consequences of the N-methyl pyrrolidone REACH restriction. Chem. 2018, 4 (9), 2010-2012.
https://doi.org/10.1016/j.chempr.2018.08.035
16. Camp, J. E.; Nyamini, S. B.; Scott, F. J., Cyrene™ is a green alternative to DMSO as a solvent for antibacterial drug discovery against ESKAPE pathogens.
RSC Med. Chem. 2020, 111-117. 10.0.4.15/C9MD00341J
17. Waaijers-van der Loop, S. L.; Dang, Z.; Rorije, E.; Janssen, N., Toxicity screening of potential bio-based Polar Aprotic Solvents (PAS). National Institute for Health and Environment (RIVM): Den Hague, The Netherlands, 2018.
18. MCCoy, M., New solvent seeks to replace NMP. Chemical & Engineering
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
19. Bioenergy International, Circa Group to head ReSolute to ReSolve commercial bio-based solvent production. In Biochemicals & Materials, 20th of December 2019. 20. Krishna, S. H.; Huang, K.; Barnett, K. J.; He, J.; Maravelias, C. T.; Dumesic, J. A.; Huber, G. W.; De Bruyn, M.; Weckhuysen, B. M., Oxygenated commodity
chemicals from chemo-catalytic conversion of biomass derived heterocycles. AlChE
J. 2018, 64 (6), 1910-1922. https://doi.org/10.1002/aic.16172
21. Brouwer, T.; Schuur, B., Bio-based Solvents as entrainers for Extractive Distillation in Aromatic/Aliphatic and Olefin/Paraffin Separation. Green Chem. 2020,
22, 5369-5375. https://doi.org/10.1039/D0GC01769H
22. Chen, D.; Ye, H.; Wu, H., Liquid–liquid equilibria of methylcyclohexane– benzene–N-formylmorpholine at several temperatures. Fluid Phase Equilib. 2007,
255 (2), 115-120. https://doi.org/10.1016/j.fluid.2007.03.013
23. Ashour, I.; Abu-Eishah, S. I., Liquid− liquid equilibria of ternary and six-component systems including cyclohexane, benzene, toluene, ethylbenzene, cumene, and sulfolane at 303.15 K. J. Chem. Eng. Data 2006, 51 (5), 1717-1722.
https://doi.org/10.1021/je060153n
24. Ghannad, S. M. R. S.; Lotfollahi, M. N.; Asl, A. H., (Liquid+ liquid) equilibria for mixtures of (ethylene glycol+ benzene+ cyclohexane) at temperatures (298.15, 308.15, and 318.15) K. J. Chem. Thermodyn. 2011, 43 (3), 329-333.
https://doi.org/10.1016/j.jct.2010.10.003
25. García, J.; Fernández, A.; Torrecilla, J. S.; Oliet, M.; Rodríguez, F., Liquid– liquid equilibria for {hexane+ benzene+ 1-ethyl-3-methylimidazolium ethylsulfate} at (298.2, 313.2 and 328.2) K. Fluid Phase Equilib. 2009, 282 (2), 117-120.
https://doi.org/10.1016/j.fluid.2009.05.006
26. Chen, D.; Ye, H.; Wu, H., Measurement and Correlation of Liquid− Liquid Equilibria of Methylcyclohexane+ Toluene+ N-Formylmorpholine at (293, 303, 313, and 323) K. J. Chem. Eng. Data 2007, 52 (4), 1297-1301.
https://doi.org/10.1021/je700036v
27. Gramajo, M. B.; Veliz, J. H.; Lucena, M. C.; González, D. A., Liquid–liquid equilibria of the methanol+ toluene+ methylcyclohexane ternary system at 278.15, 283.15, 288.15, 293.15, 298.15 and 303.15 K. J. Solution Chem. 2013, 42 (10), 2025-2033.https://doi.org/10.1007/s10953-013-0091-x 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
28. Robbins, W. K.; Hsu, C. S., Petroleum, composition. Kirk‐Othmer Encyclopedia of Chemical Technology 2000.
29. Zhou, T.; Wang, Z.; Chen, L.; Ye, Y.; Qi, Z.; Freund, H.; Sundmacher, K., Evaluation of the ionic liquids 1-alkyl-3-methylimidazolium hexafluorophosphate as a solvent for the extraction of benzene from cyclohexane:(Liquid+ liquid) equilibria. J. Chem. Thermodyn. 2012, 48, 145-149. https://doi.org/10.1016/j.jct.2011.12.006
30. Wang, R.; Li, C.; Meng, H.; Wang, J.; Wang, Z., Ternary liquid− liquid equilibria measurement for benzene+ cyclohexane+ methylimidazole, or
N-ethylimidazole, or N-methylimidazolium dibutylphosphate at 298.2 K and atmospheric pressure. J. Chem. Eng. Data 2008, 53 (9), 2170-2174.
https://doi.org/10.1021/je800376f
31. Ma, S.; Li, J.; Li, L.; Shang, X.; Liu, S.; Xue, C.; Sun, L., Liquid–Liquid Extraction of Benzene and Cyclohexane Using Sulfolane-Based Low Transition Temperature Mixtures as Solvents: Experiments and Simulation. Energ. Fuel. 2018,
32 (7), 8006-8015. https://doi.org/10.1021/acs.energyfuels.8b01524
32. Rodriguez, N. R.; Requejo, P. F.; Kroon, M. C., Aliphatic–aromatic separation using deep eutectic solvents as extracting agents. Ind. Eng. Chem. Res. 2015, 54
(45), 11404-11412. https://doi.org/10.1021/acs.iecr.5b02611
33. Hou, Y.; Li, Z.; Ren, S.; Wu, W., Separation of toluene from toluene/alkane mixtures with phosphonium salt based deep eutectic solvents. Fuel Process. Technol. 2015, 135, 99-104. https://doi.org/10.1016/j.fuproc.2014.11.001
34. Druliner, J. D.; Ittel, S. D.; Krusic, P. J.; Tolman, C. A., Process for producing a mixture containing cyclohexanol and cyclohexanone from cyclohexane. U.S. Patent 4,326,084, 1982.
35. Schuchardt, U.; Cardoso, D.; Sercheli, R.; Pereira, R.; Da Cruz, R. S.; Guerreiro, M. C.; Mandelli, D.; Spinacé, E. V.; Pires, E. L., Cyclohexane oxidation continues to be a challenge. Appl. Catal. A-Gen 2001, 211 (1), 1-17.
https://doi.org/10.1016/S0926-860X(01)00472-0
36. Kim, S. Y.; Choe, J.; Song, K. H., (Liquid+ Liquid) equilibria of (cyclohexane+ dimethyl sulfoxide+ cyclohexanone) and (cyclohexane+ dimethyl sulfoxide+
cyclohexanol) at T= 303.2 K. J. Chem. Eng. Data 2010, 55 (3), 1109-1112.
https://doi.org/10.1021/je900549r 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
37. Pei, Y.; Wang, Q.; Gong, X.; Lei, F.; Shen, B., Distribution of cyclohexanol and cyclohexanone between water and cyclohexane. Fluid Phase Equilib. 2015, 394, 129-139. https://doi.org/10.1016/j.fluid.2015.02.029
38. Yara-Varon, E.; Fabiano-Tixier, A.-S.; Balcells, M.; Canela-Garayoa, R.; Bily, A.; Chemat, F., Is it possible to substitute hexane with green solvents for extraction of carotenoids? A theoretical versus experimental solubility study. RSC Advances 2016,
6 (33), 27750-27759. https://doi.org/10.1039/C6RA03016E
39. Molina, M. C.; Mariscal, R.; Ojeda, M.; Granados, M. L., Cyclopentyl methyl ether: A green co-solvent for the selective dehydration of lignocellulosic pentoses to furfural. Bioresour. Technol. 2012, 126, 321-327.
https://doi.org/10.1016/j.biortech.2012.09.049
40. Oshima, T.; Ohkubo, N.; Fujiwara, I.; Horiuchi, T.; Koyama, T.; Ohe, K.; Baba, Y., Extraction of gold (III) using cyclopentyl methyl ether in hydrochloric acid media.
Solvent Extr. Res. Dev. 2017, 24 (2), 89-96. https://doi.org/10.15261/serdj.24.89
41. Maurer, G.; Prausnitz, J., On the derivation and extension of the UNIQUAC equation. Fluid Phase Equilib. 1978, 2 (2), 91-99. https://doi.org/10.1016/0378-3812(78)85002-X
42. Staverman, A., The entropy of high polymer solutions. Generalization of formulae. Rec. Trav. Chim. Pays Bas 1950, 69 (2), 163-174.
https://doi.org/10.1002/recl.19500690203
43. Banerjee, T.; Singh, M. K.; Sahoo, R. K.; Khanna, A., Volume, surface and UNIQUAC interaction parameters for imidazolium based ionic liquids via polarizable continuum model. Fluid Phase Equilib. 2005, 234 (1-2), 64-76.
https://doi.org/10.1016/j.fluid.2005.05.017
44. Gupta, S.; Rawat, B.; Goswami, A.; Nanoti, S.; Krishna, R., Isobaric vapour— liquid equilibria of the systems: Benzene—triethylene glycol, toluene—triethylene glycol and benzene—N-methylpyrrolidone. Fluid Phase Equilib. 1989, 46 (1), 95-102.
https://doi.org/10.1016/0378-3812(89)80278-X
45. Zhang, H., Measurements and comparative study of ternary liquid–liquid equilibria for water+ acrylic acid+ cyclopentyl methyl ether at (293.15, 303.15, and 313.15) K and 100.249 kPa. J. Chem. Eng. Data 2015, 60 (5), 1371-1376.
https://doi.org/10.1021/je501085y
46. Treybal, R. E., Liquid extraction. 2d ed. ed.; McGraw-Hill: New York, 1963. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
47. Marcilla, A.; Serrano, M.; Reyes-Labarta, J.; Olaya, M., Checking liquid–liquid plait point conditions and their application in ternary systems. Ind. Eng. Chem. Res.
2012, 51 (13), 5098-5102. https://doi.org/10.1021/ie202793r
48. Beegle, B. L.; Modell, M.; Reid, R. C., Thermodynamic stability criterion for pure substances and mixtures. AlChE J. 1974, 20 (6), 1200-1206.
https://doi.org/10.1002/aic.690200621
49. González, E. J.; Calvar, N.; Gómez, E.; Domínguez, Á., Application of
[EMim][ESO4] ionic liquid as solvent in the extraction of toluene from cycloalkanes: Study of liquid–liquid equilibria at T= 298.15 K. Fluid Phase Equilib. 2011, 303 (2), 174-179. https://doi.org/10.1016/j.fluid.2011.01.021
50. Gutierrez, J. P.; Meindersma, W.; De Haan, A. B., Binary and ternary (liquid+ liquid) equilibrium for {methylcyclohexane (1)+ toluene (2)+
1-hexyl-3-methylimidazolium tetracyanoborate (3)/1-butyl-3-1-hexyl-3-methylimidazolium tetracyanoborate (3)}. J. Chem. Thermodyn. 2011, 43 (11), 1672-1677.
https://doi.org/10.1016/j.jct.2011.05.029
51. Domínguez, I.; Calvar, N.; Gómez, E.; Domínguez, Á., Separation of toluene from cyclic hydrocarbons using 1-butyl-3-methylimidazolium methylsulfate ionic liquid at T= 298.15 K and atmospheric pressure. J. Chem. Thermodyn. 2011, 43 (5), 705-710. https://doi.org/10.1016/j.jct.2010.12.012
52. Israelachvili, J. N., 6 - Van der Waals Forces. In Intermolecular and Surface Forces (Third Edition), Israelachvili, J. N., Ed. Academic Press: San Diego, 2011; pp 107-132.
53. Galvao, J.; Davis, B.; Tilley, M.; Normando, E.; Duchen, M. R.; Cordeiro, M. F., Unexpected low-dose toxicity of the universal solvent DMSO. FASEB J. 2014, 28 (3), 1317-1330. DOI: 10.1096/fj.13-235440
54. O'Reilly, D.; Peterson, E.; Hogenboom, D., Self‐Diffusion Coefficients and Rotational Correlation Times in Polar Liquids. V. Cyclohexane, Cyclohexanone, and Cyclohexanol. J. Chem. Phys. 1972, 57 (9), 3969-3976.
https://doi.org/10.1063/1.1678869
55. Petro, A. J., The dipole moment of the carbon-carbon bond. J. Am. Chem. Soc. 1958, 80 (16), 4230-4232. https://doi.org/10.1021/ja01549a027 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
56. Watanabe, K.; Yamagiwa, N.; Torisawa, Y., Cyclopentyl methyl ether as a new and alternative process solvent. Org. Process Res. Dev. 2007, 11 (2), 251-258.
https://doi.org/10.1021/op0680136
57. Schauer, M.; Bernstein, E., Calculations of the geometry and binding energy of aromatic dimers: benzene, toluene, and toluene–benzene. J. Chem. Phys. 1985, 82
(8), 3722-3727. http://dx.doi.org/10.1063/1.448908
58. De Graff, R. R.; Perga, M. W., Method for aromatic hydrocarbon recovery. U.S. Patent 3,466,346, 1969.
59. Thompson, H. L., Process for the extraction and recovery of aromatic hydrocarbons. U.S. Patent 3,544,453A, 1970.
60. Morin, R. D.; Fishel, J. B.; Bearse, A. E., Separation of aromatic hydrocarbons from non-aromatic hydrocarbons utilizing a lactam-water solvent. U.S. Patent
2,933,448A, 1960.
61. Jones, E. A.; Broughton, D. B., Solvent extraction process for recovery of aromatic hydrocarbons. U.S. Patent 3,173,966A, 1965.
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For Table of Content Use Only
Cyrene™ extracts solutes more polar than methylcyclohexane selectively from the hydrocarbon phase 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
