Separation of Alcohols from n-Tetradecane Using 1-Ethyl-3-methylimidazolium Hydrogensulfate
, Claire Besnard 2, Flavien Ivol 2, Carine Maaliki 2, Terri-Louise Hughes 3, Peter Goodrich 3 and Johan Jacquemin 1,2,*
Round 1
Reviewer 1 Report
The manuscript Separation of alcohols from n-tetradecane using 1-ethyl-3-me-2 thylimidazolium hydrogensulfate submitted to Thermo - Manuscript Number: thermo-1801403 describes the impact of an ionic liquid on the selectivity and distribution ratio for the aliphatic alcohols from n-tetradecane. The text is logically built, and the conclusions are in line with the figures and tables presented.
Author Response
Response to Reviewer 1 Comments
First of all, we would like to express our gratitude to the referee for their careful examination of our work. We have carefully considered the reviewer’s comments on our manuscript and have made some changes to address the comments of reviewer’s where appropriate. Please note that all corrections and changes made have been highlighted in this revision using the track changes option to help readers. We will now give a detailed response below:
Referee #1: Comments and Suggestions for Authors
The manuscript Separation of alcohols from n-tetradecane using 1-ethyl-3-me-2 thylimidazolium hydrogensulfate submitted to Thermo - Manuscript Number: thermo-1801403 describes the impact of an ionic liquid on the selectivity and distribution ratio for the aliphatic alcohols from n-tetradecane. The text is logically built, and the conclusions are in line with the figures and tables presented.
Response: We thank the referee for their very strong positive feedback on our communication and to allow its publication as is.
Reviewer 2 Report
This work contains novel results on the extraction of alcohols from n-tetradecane using various extraction solvents at a range of temperatures under ambient pressure. The article is well written from a technical and scientific perspective. I recommended this work for publication after a minor revision.
1. How was the accuracy of temperature measured? Is there any deviation? That should be added, if yes “A temperature of 303 K was chosen 131 to be slightly above the melting point (300 K) of sulfolane.”
2. Were the extracting solvents recycled? Add the details extracting procedure and their NMR characterization, if yes.
3. What is the stability of sulfolane under the applied conditions? Is there any degradation that occurred during the extraction of alcohol?
4. Typo--> <300pm, it should be ppm
5. Add the relevant reference, particular for toxicity “The hydrophilic ionic liquid 1-ethyl-3-methylimidazolium hydrogensulfate [C2mim][HSO4] was selected on the basis of price, commercial availability, and low toxicity”
Author Response
Response to Reviewer 2 Comments
First of all, we would like to express our gratitude to the referee for their careful examination of our work. We have carefully considered the reviewer’s comments on our manuscript and have made some changes to address the comments of reviewer’s where appropriate. Please note that all corrections and changes made have been highlighted in this revision using the track changes option to help readers.
Referee #2: Comments and Suggestions for Authors
This work contains novel results on the extraction of alcohols from n-tetradecane using various extraction solvents at a range of temperatures under ambient pressure. The article is well written from a technical and scientific perspective. I recommended this work for publication after a minor revision.
Response: We thank the referee for their very strong positive feedback on our communication and to allow its publication after a minor revision.
We will now give a detailed response below:
- How was the accuracy of temperature measured? Is there any deviation? That should be added, if yes “A temperature of 303 K was chosen to be slightly above the melting point (300 K) of sulfolane.”
Response: We thank the referee for providing these comments. Accuracy of the temperature was added in this revision as follows:
“The set temperature (± 0.5 K) was controlled using a standard Pt 100 Ω resistance thermometer with a precision of ± 0.1 K and an accuracy of ± 0.5 K.”
- Were the extracting solvents recycled? Add the details extracting procedure and their NMR characterization, if yes.
Response: We thank the referee for providing this comment. Extracting solvent was not recycled during this work, which must be further quantified to truly evaluate the potential of selected IL. However, our initial goal was to provide evidence and novel insights on the extraction of alcohols from n-tetradecane.
- What is the stability of sulfolane under the applied conditions? Is there any degradation that occurred during the extraction of alcohol?
Response: We thank the referee for providing these comments. No degradation of the sulfolane was observed during our measurements at 295 K. The following sentence was added accordingly:
“It is important to highlight that no degradation of the sulfolane nor the ionic liquid was observed during our measurements set at 295 K.”
- Typo--> <300pm, it should be ppm
Response: We thank the referee for highlighting this typo which was corrected during this revision.
- Add the relevant reference, particular for toxicity “The hydrophilic ionic liquid 1-ethyl-3-methylimidazolium hydrogensulfate [C2mim][HSO4] was selected on the basis of price, commercial availability, and low toxicity”
Response: We thank the referee for providing these comments. We agree that this sentence must be attested thanks to references. The following references were added to this revision. Furthermore, we temper the highlighted sentence in this revision as follows:
The hydrophilic ionic liquid 1-ethyl-3-methylimidazolium hydrogensulfate [C2mim][HSO4] was selected on the basis of price, commercial availability, as well as, its lower toxicity in comparison with other aprotic ionic liquids. [25-28]
Added References:
[25] Ventura, S.P.M.; de Barros, R.L.F.; Sintra, T.; Soares, C.M.F.; Lima, Á.S.; Coutinho, J.A.P.; Simple Screening Method to Identify Toxic/Non-Toxic Ionic Liquids: Agar Diffusion Test Adaptation. Ecotoxicology and Environmental Safety 2012, 83, 55-62
[26] Ventura, S.P.M.; Silva, F.A.e; Quental, M.V.; Mondal, D.; Freire, M.G.; Coutinho, J.A.P.; Ionic-Liquid-Mediated Extraction and Separation Processes for Bioactive Compounds: Past, Present, and Future Trends. Chemical Reviews 2017 117 (10), 6984-7052
[27] Greer, A.J.; Jacquemin, J.; Hardacre, C.; Industrial Applications of Ionic Liquids. Molecules 2020, 25, 5207. DOI: 10.3390/molecules25215207
[28] Buettner, C.S.; Cognigni, A.; Schröder, C.; Bica-Schröder, K.; Surface-Active Ionic Liquids: A Review. J. Mol. Liq. 2022, 347, 118160
Reviewer 3 Report
Report on the Manuscript Number: Ms. ID- thermo-1801403
The submitted entitled “Separation of alcohols from n-tetradecane using 1-ethyl-3-methylimidazolium hydrogensulfate” review in ‘thermo-1801403, manuscript at first glance manuscript looks nice piece of work. G. Ah-Lung et al. presented great effort to establish to separate alcohols containing (alkyl chain C8-C12) from tetradecane using ionic liquids as extraction media. This manuscript demonstrates various laboratory performed experiments including distribution and selectivity calculations. Although the submitted article is a full-length article therefore all sections have been carefully reviewed, during reviewing there are few comments / questions / suggestions raised one-by-one (below), which will help to improve the quality further.
[Minor Revision]
Comments are as follows;
1) Abstract: Range of temperature and pressure should be clearly mentioned.
2) In introduction part there are various place require to improvement by adding;
A) How much is this extraction important for the industrial processes? Specially for longer alkyl chained alcohols.
B) What are the limitations that can be improved through these experiments / study in current scenarios?
C) As we are aware that ionic liquids have a number of designer possibilities, the reason behind selecting said ionic liquids for this study. If the reason is based on price, commercial availability and low toxicity, author (s) may provide the reference if available.
3) In recent published work, γ-Valerolactone has been considered as a green solvent for extraction of alcohols n-tetradecane (C. E. S. Dantas and R. Ceriani, J. Chem. Eng. Data 2022, 67, 6, 1460–1473), how do authors see this research paper by comparing their own submitted manuscript?
4) Experimental Section:
A) What is the data recording procedure at the temperature range of the system, while studying LLE?
B) How precisely separation of supernatant / phase is taken without any contamination for further study?
C) Calibration and reproducibility give the strength of experimental results.
5) I believe a graphical abstract or drawing figure will be helpful to understand at a glance.
6) If possible, similarly a chart of table 2 attracts the maximum number of readers and provides ease. This plot will help to show the capacity for the ionic liquid and affinity with alcohols directly.
7) Is this line corresponding to future work? (Therefore, any new alkyl-sulfate ionic liquid that is formed is also going to be more hydrophobic in character)
Author Response
Response to Reviewer 3 Comments
First of all, we would like to express our gratitude to the referee for their careful examination of our work. We have carefully considered the reviewer’s comments on our manuscript and have made some changes to address the comments of reviewer’s where appropriate. Please note that all corrections and changes made have been highlighted in this revision using the track changes option to help readers.
Referee #3: Comments and Suggestions for Authors
The submitted entitled “Separation of alcohols from n-tetradecane using 1-ethyl-3-methylimidazolium hydrogensulfate” review in ‘thermo-1801403, manuscript at first glance manuscript looks nice piece of work. G. Ah-Lung et al. presented great effort to establish to separate alcohols containing (alkyl chain C8-C12) from tetradecane using ionic liquids as extraction media. This manuscript demonstrates various laboratory performed experiments including distribution and selectivity calculations. Although the submitted article is a full-length article therefore all sections have been carefully reviewed, during reviewing there are few comments / questions / suggestions raised one-by-one (below), which will help to improve the quality further. [Minor Revision] Comments are as follows.
Response: We thank the referee for their very strong positive feedback on our communication and to allow its publication after a minor revision. We will now give a detailed response below:
1) Abstract: Range of temperature and pressure should be clearly mentioned.
Response: We thank the referee for highlighting this point, range of temperature has been added into this revision.
2) In introduction part there are various place require to improvement by adding;
A) How much is this extraction important for the industrial processes? Specially for longer alkyl chained alcohols.
B) What are the limitations that can be improved through these experiments / study in current scenarios?
C) As we are aware that ionic liquids have a number of designer possibilities, the reason behind selecting said ionic liquids for this study. If the reason is based on price, commercial availability and low toxicity, author (s) may provide the reference if available.
Response: We thank the referee for sharing these comments. However, we do believe that the two first points were already clearly mentioned in the original manuscript as to date, no benchmark solvents is recommended for such a purpose. However, we do agree that the point C was not properly covered. For that reason, we tempered this sentence and added 4 references as follows.
The hydrophilic ionic liquid 1-ethyl-3-methylimidazolium hydrogensulfate [C2mim][HSO4] was selected on the basis of price, commercial availability, as well as, its lower toxicity in comparison with other aprotic ionic liquids. [25-28]
Added References:
[25] Ventura, S.P.M.; de Barros, R.L.F.; Sintra, T.; Soares, C.M.F.; Lima, Á.S.; Coutinho, J.A.P.; Simple Screening Method to Identify Toxic/Non-Toxic Ionic Liquids: Agar Diffusion Test Adaptation. Ecotoxicology and Environmental Safety 2012, 83, 55-62
[26] Ventura, S.P.M.; Silva, F.A.e; Quental, M.V.; Mondal, D.; Freire, M.G.; Coutinho, J.A.P.; Ionic-Liquid-Mediated Extraction and Separation Processes for Bioactive Compounds: Past, Present, and Future Trends. Chemical Reviews 2017 117 (10), 6984-7052
[27] Greer, A.J.; Jacquemin, J.; Hardacre, C.; Industrial Applications of Ionic Liquids. Molecules 2020, 25, 5207. DOI: 10.3390/molecules25215207
[28] Buettner, C.S.; Cognigni, A.; Schröder, C.; Bica-Schröder, K.; Surface-Active Ionic Liquids: A Review. J. Mol. Liq. 2022, 347, 118160
3) In recent published work, γ-Valerolactone has been considered as a green solvent for extraction of alcohols n-tetradecane (C. E. S. Dantas and R. Ceriani, J. Chem. Eng. Data 2022, 67, 6, 1460–1473), how do authors see this research paper by comparing their own submitted manuscript?
Response: We thank the referee for sharing this information. However, we cannot compare our data with those published by this group as they investigated the extraction of lighter alcohols from mixtures with n-tetradecane. However, we do agree that this work is very important explaining why we cited this paper in this revision (see. Ref 7) as follows:
“More recently, γ-valerolactone has been also reported as a potential extractant of polar oxygenated solutes (i.e. light alcohols and carboxylic acids) from their mixture with n-tetradecane [7].”
4) Experimental Section:
A) What is the data recording procedure at the temperature range of the system, while studying LLE?
B) How precisely separation of supernatant / phase is taken without any contamination for further study?
C) Calibration and reproducibility give the strength of experimental results.
Response: We thank the referee for sharing these comments. Missing information regarding reproducibility, accuracy, and temperature control has been added in the experimental section as well as in the footnote of each Table. Briefly, all solubility data reported, herein, were determined after stirring each binary or ternary mixture for at least 1 h followed by a settling period of 4-6 h to ensure that the thermodynamic equilibrium was reached. A sample was then taken from each equilibrium phase into which the system had split. The determination of the composition of each component in each phase was carried out by means of 1H-NMR spectroscopy using as reference, d6-DMSO, placed into a sealed probe in order to avoid sample contamination. The expected uncertainty of ternary systems was evaluated by analysis of samples of known composition. Samples of the three components whose composition lay in the homogeneous region were prepared by weight (within a reproducibility and an accuracy of 1·10-3 and 5·10-3 in mole fraction units, respectively).
5) I believe a graphical abstract or drawing figure will be helpful to understand at a glance.
Response: We thank the referee for sharing this comment. As requested, a graphical abstract has been proposed.
6) If possible, similarly a chart of table 2 attracts the maximum number of readers and provides ease. This plot will help to show the capacity for the ionic liquid and affinity with alcohols directly.
Response: We thank the referee for sharing this comment. However, we do think that this table is enough to highlight our findings.
7) Is this line corresponding to future work? (Therefore, any new alkyl-sulfate ionic liquid that is formed is also going to be more hydrophobic in character)
We thank the referee for providing this comment. No, this sentence is just explaining our data. To help readers, we decided to slightly modify this sentence as follows:
“As the chain length of the alcohol increases from 1-hexanol through to 1-dodecanol the hydrophobicity also increases. Therefore, any new alkylsulfate ionic liquid that is formed during the reactive extraction (Equation 3) is also going to be more hydrophobic in character.”
