Review Reports

Round 1

Reviewer 1 Report

The manuscript entitled “An Optimization Study on Biomass Hydrogenation to Ethylene Glycol” submitted by Azlan Shan Hussain is under consideration for publication in the journal “Processes”. The research regards the application of a multivariate approach, as the response surface methodology (RSD) to optimise (maximise) the yield of ethylene glycol (EG) under the influence of specific parameters. Responses demonstrated the importance of four parameters to the yield of the desiderated product. It is appearing as the manuscript is not well grammarly corrected, and the introduction should be written clearly by condensed sentences. All the manuscript should be re-written critically. So that, I recommend revising the manuscript by following these suggestions:

Please re-write the introduction. In addition, authors should highlight the importance of their work, as well as the advantages of using multivariate approaches in this field. From line 68 to 80. The sentences are very confused. Please list the affecting variables in a table in Material and Methods (for example, at the end of section 2.5). It could be clear. Paragraph 3.2. Authors should explain the choose of levels for all the selected factors. In addition, the pre-treatment of fibres could be included in the model as affecting factor. As example, a full or fractional factorial design may be applied to screen the significance of main factors and can help to better estimate the involving one. If the authors could provide it, please mentioned it in the manuscript. It could be integrated with results achieved with ANOVA. Line 178 to 180, Paragraph 3.3. The sentence was already used and repeating the one reported in 3.2. Equation at line 247. From the equation, it is noted as all the factors contribute positively to the selected response, particularly with the higher contribution from factor D (+ 647). Alternatively, the weight of linear interaction terms is negative (especially in the case of the interaction between AD factors, with values of -261). This can suggest the further experimental demand. In this case, I do not understand the experimental conditions used for model validation (are probably listed in Conclusions?).. Please write them at the end of validation tests and discuss them properly. The bibliography should be critical revised. A lot of papers from the same groups…

Author Response

Dear Editors,

Subject: Revision and resubmission of manuscript Processes-669498

Thank you for the opportunity and give us ample time to revise our paper entitled “An optimization study on biomass hydrogenation to ethylene glycol”. The suggestions offered by the reviewers have been immensely helpful, and we also appreciate your insightful and constructive comments on revising the manuscript.

We have included the reviewer comments immediately after this letter and have responded to them individually, indicating how we addressed each suggestion and also describe the changes that we have made. The revisions have been approved by all 4 authors and I would continue to be the corresponding author. The changes are tracked in the documents as you requested.

We hope you find the revised manuscript acceptable for publication. Thank you once again for your consideration.

 

Please address all correspondence concerning this manuscript to me at azlanshah_hh@petronas.com.my.

 

Sincerely,

Azlan Shah Hussain

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript titled “An Optimization Study on Biomass Hydrogenation to Ethylene Glycol” evaluates the synthesis of ethylene glycol from a renewable source such as biomass. In my opinion, the manuscript is interesting to be published in the special issue of this journal. However, the manuscript can present several weaknesses that must be improved. The work is too focused on the verification of the method of analysis, I think that such a detailed study is not relevant for this journal. In my opinion, the study should be more focused on the catalytic process (the economic sustainability of the process, the justification for why these catalysts are good or better than those reported in the literature, the comparison of the data with those shown in the literature through a table and the characterization of the catalysts).
With regards to the fibers, the authors should provide more information. Maybe the authors can enrich the characterization or they can indicate the number of units of each fiber.
Did the authors analyze the possible leaching of the Ni and/or W species after the catalytic tests?
In spite of this journal is not focused on the characterization of the catalysis. In my opinion, the characterization of the active phase can be a key factor to justify the catalytic behavior of these catalytic systems.

Author Response

Dear Editors,

Subject: Revision and resubmission of manuscript Processes-669498

Thank you for the opportunity and give us ample time to revise our paper entitled “An optimization study on biomass hydrogenation to ethylene glycol”. The suggestions offered by the reviewers have been immensely helpful, and we also appreciate your insightful and constructive comments on revising the manuscript.

We have included the reviewer comments immediately after this letter and have responded to them individually, indicating how we addressed each suggestion and also describe the changes that we have made. The revisions have been approved by all 4 authors and I would continue to be the corresponding author. The changes are tracked in the documents as you requested.

We hope you find the revised manuscript acceptable for publication. Thank you once again for your consideration.

 

Please address all correspondence concerning this manuscript to me at azlanshah_hh@petronas.com.my.

 

Sincerely,

Azlan Shah Hussain

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I would like to thank all authors for the modification of the manuscript. At this point, the paper can be accepted for publication. 

Author Response

Azlan Shah Hussain

PETRONAS Research Sdn Bhd,

Lot 2388 & 3289, Jalan Ayer Itam,

Kawasan Institusi Bangi,

43000 Kajang, Selangor,

MALAYSIA

azlanshah_hh@petronas.com.my

 

Publishing Director

Journal of Processes

MDPI

 

February 24, 2020

 

Dear Editors,

Subject: Revision and resubmission of manuscript Processes-669498

Thank you for the opportunity and time to revise our paper entitled “Optimization study of biomass hydrogenation to ethylene glycol using response surface methodology”. The suggestions offered by the reviewers have been immensely helpful, and we also appreciate your insightful and constructive comments on revising the manuscript.

We have included the reviewer comments immediately after this letter and have responded to them individually, indicating how we addressed each suggestion and also describe the changes that we have made. The revisions have been approved by all 4 authors and I would continue to be the corresponding author. The changes are tracked in the documents as you requested.

We hope you find the revised manuscript acceptable for publication. Thank you once again for your consideration.

 

Please address all correspondence concerning this manuscript to me at azlanshah_hh@petronas.com.my.

 

Sincerely,

Azlan Shah Hussain

 

 

Reviewer Comments, Author Responses and Manuscript Changes

Reviewer 1

Comment: I would like to thank all authors for the modification of the manuscript. At this point, the paper can be accepted for publication.

Response: Thank you for this kind comment.

Reviewer 2 Report

The authors have improved the quality of the manuscript after the suggestion of the reviewers. I only propose small corrections.

 

The title is very general. In my opinion, the authors should highlight the stadistical study in the title.

The authors should highlight what are the positive effects of the optimization process in comparison with those data reported in the literature.

 

Author Response

Azlan Shah Hussain

PETRONAS Research Sdn Bhd,

Lot 2388 & 3289, Jalan Ayer Itam,

Kawasan Institusi Bangi,

43000 Kajang, Selangor,

MALAYSIA

azlanshah_hh@petronas.com.my

 

Publishing Director

Journal of Processes

MDPI

 

February 24, 2020

 

Dear Editors,

Subject: Revision and resubmission of manuscript Processes-669498

Thank you for the opportunity and time to revise our paper entitled “Optimization study of biomass hydrogenation to ethylene glycol using response surface methodology”. The suggestions offered by the reviewers have been immensely helpful, and we also appreciate your insightful and constructive comments on revising the manuscript.

We have included the reviewer comments immediately after this letter and have responded to them individually, indicating how we addressed each suggestion and also describe the changes that we have made. The revisions have been approved by all 4 authors and I would continue to be the corresponding author. The changes are tracked in the documents as you requested.

We hope you find the revised manuscript acceptable for publication. Thank you once again for your consideration.

 

Please address all correspondence concerning this manuscript to me at azlanshah_hh@petronas.com.my.

 

Sincerely,

Azlan Shah Hussain

 

Reviewer 2

Comment 1: The authors have improved the quality of the manuscript after the suggestion of the reviewers. I only propose small corrections. The title is very general. In my opinion, the authors should highlight the statistical study in the title.

Response 1: Thank you for this kind comment. We have changed the title to reflect the statistical study, the proposed new title is “Optimization Study of Biomass Hydrogenation to Ethylene Glycol using Response Surface Methodology”.

Comment 2: The authors should highlight what are the positive effects of the optimization process in comparison with those data reported in the literature.

Response 2: Thank you for this comment. The following paragraph is inserted as a final paragraph in conclusion to include the positive effects of this study when compare to those data reported in the literature:

“Having a high coefficient of determination (R²) value of more than 0.98, the quadratic model developed in this study could be used to give a precise EG yield prediction even when the 4 parameters are being modified in the future. Although many research groups had reported their findings on glucose, cellulose or biomass hydrogenation for EG production, there wasn’t any literature reporting effects of factors as well as effects of confounding factors affecting EG yield. This study filled in this missing gap nicely.”

All the above changes have been made in the manuscript and “track changes” option has been activated in the manuscript for easy tracking.

 

We hope you find the revised manuscript acceptable for publication. Thank you once again for your consideration.

 

Author Response File: Author Response.pdf