Experimental Validation of a Test Apparatus for the Evaluation of Hydrogen Permeation in Silane-Modified Sealants on Fuel-Cell-Powered Vehicles

Round 1

Reviewer 1 Report

This manuscript evaluates the hydrogen permeability of two industrial polymeric joint sealants produced by Vaber, Advantseal FR, and Cristalcar Plus, where this analysis was used to carry out design checks for the power car vehicle of the train. The idea is good; however, many issues should be addressed according to the following comments:

1) The overall presentation, readability, and more graphical results and analysis with discussions are mandatory. Please, correct the language problems, it is weak from the Grammarly and sequences of events, I catch 22 errors by using a personal program, and the authors should cure them carefully. Further, don't use the pronoun "we" in the whole manuscript.

2) The "Abstract" section should be more intensively focused on the main idea directly and must contain the contribution of this manuscript supported with numerical result indicators.

3) The "Introduction" section should be made much more impressive by highlighting your contributions. The novelty of this manuscript must be explained simply and clearly in points at the end of the introduction section. Note that, the introduction section should consist of three parts, i.e., a general introduction to the topic, followed by a literature survey, then the contribution clarifications.

4) The introduction section should be enriched with up-to-date references for the last three years, by adding and citing the latest trends in the area of fuel cells and vehicles. E.g., Optimal Estimation of Proton Exchange Membrane Fuel Cells Parameter & Sealing Performance Analysis of Rubber O-ring in high-pressure Gaseous Hydrogen based on finite element method & Optimal scheduling of DG and EV parking lots simultaneously with demand response based on self‐adjusted PSO and K‐means clustering.

5) It is mandatory to check all the citing references of equations 1 & 2 and add more description equations. In addition, check carefully all the abbreviation definitions, symbols, and standard units in the whole manuscript. I catch some errors and the other symbols are not defined, please define the abbreviations of (UV, SATP, TCD, TDS,…).

6) The resolution and quality of result figures must be modified; they should be presented as close to the camera-ready format. Also, please don't use the symbol abbreviations on X-Y-axes, they must have the full name with their SI units. In addition, try to make zoom in at the effective area on each curve.

 

7) The conclusion section should be more concentrated and supported by the numerical results. Also, the authors may propose some interesting problems as future work in the conclusion.

Author Response

Dear Reviewer,

 

thank you for your revision and your useful tips. Below are the answers in cursive point by point:

 

1) The overall presentation, readability, and more graphical results and analysis with discussions are mandatory. Please, correct the language problems, it is weak from the Grammarly and sequences of events, I catch 22 errors by using a personal program, and the authors should cure them carefully. Further, don't use the pronoun "we" in the whole manuscript. The Grammarly and the text in general was revised and the mistakes was corrected. The pronoun “we” was eliminated.

 

2) The "Abstract" section should be more intensively focused on the main idea directly and must contain the contribution of this manuscript supported with numerical result indicators. The Abstract was improved and the contribution of this manuscript was explained with numerical results.

 

3) The "Introduction" section should be made much more impressive by highlighting your contributions. The novelty of this manuscript must be explained simply and clearly in points at the end of the introduction section. Note that, the introduction section should consist of three parts, i.e., a general introduction to the topic, followed by a literature survey, then the contribution clarifications. The Introduction section was reviewed and the contributions of this work was explained.

 

4) The introduction section should be enriched with up-to-date references for the last three years, by adding and citing the latest trends in the area of fuel cells and vehicles. E.g., Optimal Estimation of Proton Exchange Membrane Fuel Cells Parameter & Sealing Performance Analysis of Rubber O-ring in high-pressure Gaseous Hydrogen based on finite element method & Optimal scheduling of DG and EV parking lots simultaneously with demand response based on self‐adjusted PSO and K‐means clustering. The Introduction section and the references was ampliated with the suggested papers.

 

5) It is mandatory to check all the citing references of equations 1 & 2 and add more description equations. In addition, check carefully all the abbreviation definitions, symbols, and standard units in the whole manuscript. I catch some errors and the other symbols are not defined, please define the abbreviations of (UV, SATP, TCD, TDS,…). The equation references was indicated and the abbreviations was explained.

 

6) The resolution and quality of result figures must be modified; they should be presented as close to the camera-ready format. Also, please don't use the symbol abbreviations on X-Y-axes, they must have the full name with their SI units. In addition, try to make zoom in at the effective area on each curve. The resolution of result figure was improved and the units was reported without abbreviations.

 

 

 

7) The conclusion section should be more concentrated and supported by the numerical results. Also, the authors may propose some interesting problems as future work in the conclusion. The conclusion section was improved and numerical results was included.

 

I remain available for any clarification.

 

Best Regards,

 

Patrizio Locatelli

Reviewer 2 Report

1. Introduction section needs explanation on what does the author want to show in this paper. It is also beneficial to discuss the flow of the paper at the end of introduction. Also explain the advantages of the test bench designed by BeonD (maybe a sentence or two to explain why this is better when compared to references 13-15.

2. "The gas molecules that permeate the adhesive septum are conveyed by the carrier gas to a continuous cycle sampler, which repeatedly injects its contents into a gas chromatograph." Is this gas chromatograph 12 in table 1?

3. Please explain the abbreviations like FR, TCD etc.,

4. "The test apparatus set up by BeonD, validated on this test cycle," What does the author mean by validated? What are they validating?

Author Response

Dear Reviewer,

 

thank you for your revision and your useful tips. Below are the answers in cursive point by point:

 

1. Introduction section needs explanation on what does the author want to show in this paper. It is also beneficial to discuss the flow of the paper at the end of introduction. Also explain the advantages of the test bench designed by BeonD (maybe a sentence or two to explain why this is better when compared to references 13-15. The Introduction section was improved and the advantages of the test bench designed by BeonD was explained.

 

2. "The gas molecules that permeate the adhesive septum are conveyed by the carrier gas to a continuous cycle sampler, which repeatedly injects its contents into a gas chromatograph." Is this gas chromatograph 12 in table 1? Yes, it is the gas chromatograph.

 

3. Please explain the abbreviations like FR, TCD etc., Done in the manuscript, in particular TCD is Thermal Conductivity Detector and FR is Fire Retardant.

 

4. "The test apparatus set up by BeonD, validated on this test cycle," What does the author mean by validated? What are they validating? By "validation" we mean that the sensors applied to the test bench did not register any leaks in the external environment and the test apparatus is compliant with the reference standard.

 

I remain available for any clarification.

 

Best Regards,

 

Patrizio Locatelli

Reviewer 3 Report

In their study, Patrizio Tiziano Locatelli Quacchia et al. described an experimental validation of a test apparatus for the evaluation of hydrogen permeation in silane-modified sealants on fuel cell-powered vehicles. The background of the study and its relevance was appreciably presented. Materials and methods used in the permeability test were thoroughly described. The two sealants utilized were Advantseal FR and Cristal Car with thicknesses of 3mm and 6mm each. Results for both sealants revealed negligible hydrogen permeation and non-detection for the 3mm and 6mm, respectively. Further areas of useful applicability of the test apparatus were suggested. Consequently, the research article is publishable after consideration of the following revisions:

1.         Line 53; … focusing on the use of hydrogen in vehicles…

2.         Line 58; … operating hydrogen-hybrid trains on the British railway network…

3.         Lines 18, 71, 73, 79, 81, 86, 116; “silane-modified” should replace “silane modified” for consistency.

4.         Lines 128, 165, 256; the “2” in the hydrogen gas formula should be a subscript (ie H2)

5.         Lines 161, 240, 257, 264, 269; “Cristal Car” and “Cristalcar” are used interchangeably. One could be used to ensure consistency.

6.         Figure 2; label resolution could be improved. The names of each label should be indicated if necessary.

7.         Line 194; … the samples used for the hydrogen permeability test were reported…

8.         Figure 4; image could be well organized into subsets and well described.

9.         Line 222; …Knowing the flow through the lower chamber, …

10.       Line 227; … F is the flow rate in ml/min, …

11.       Line 228; … molar mass of hydrogen gas…

12.       Line 304; the Reference could be well organized, especially Ref 1, 2, 16, 17, and 18.

13.       Finally, the results and discussion could be improved. For example, including more relevant permeability graphs.

Author Response

Dear Reviewer,

 

thank you for your revision and your useful tips. Below are the answers in cursive point by point:

 

1. Line 53; … focusing on the use of hydrogen in vehicles… Done
2. Line 58; … operating hydrogen-hybrid trains on the British railway network… Done
3. Lines 18, 71, 73, 79, 81, 86, 116; “silane-modified” should replace “silane modified” for consistency. Done
4. Lines 128, 165, 256; the “2” in the hydrogen gas formula should be a subscript (ie H2) Done
5. Lines 161, 240, 257, 264, 269; “Cristal Car” and “Cristalcar” are used interchangeably. One could be used to ensure consistency. “Cristalcar” is the correct name and it was corrected in all manuscript.
6. Figure 2; label resolution could be improved. The names of each label should be indicated if necessary. The resolution was improved and the names of each label was indicated.
7. Line 194; … the samples used for the hydrogen permeability test were reported… Done
8. Figure 4; image could be well organized into subsets and well described. Done
9. Line 222; …Knowing the flow through the lower chamber, … Done
10. Line 227; … F is the flow rate in ml/min, … Done
11. Line 228; … molar mass of hydrogen gas… Done
12. Line 304; the Reference could be well organized, especially Ref 1, 2, 16, 17, and 18. Done

13.       Finally, the results and discussion could be improved. For example, including more relevant permeability graphs. More tables with the details of each measure were included.

 

I remain available for any clarification.

 

Best Regards,

 

Patrizio Locatelli

Round 2

Reviewer 1 Report

All of my concerns are adjusted, thanks.