Impact of the Manufacturing Processes of Aromatic-Polymer-Based Carbon Fiber on Life Cycle Greenhouse Gas Emissions
Round 1
Reviewer 1 Report
Dear authors,
the paper's topic is very interesting. Environmental assessment of carbon fiber is an important issue that needs to be explored. However the article is superficial in some places and needs to be improved.
Introduction: the introduction needs to be extended. Not enough articles were cited. For example you could add:
Interactive optimization of the resin transfer molding using a general-purpose tool: a case study; International Journal on Interactive Design and Manufacturing Volume 14, Issue 1, Pages 295 - 3081 March 2020
A methodological approach for the design of composite tanks produced by filament winding; Computer-Aided Design and Applications, 17, Issue 6, Pages 1229 – 12402020
Method: the method is not sufficiently described, the functional unit is not clear, the boundary conditions are not well defined, the method for the analysis of the results has not been presented
Discussion: the phase of discussion of the results is fundamental. in this work the section shown is not sufficient. we need to increase the details
Author Response
Response to Reviewer 1.
Please see attached for my Response to Reviewer 1.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The present manuscript entitled “Impact of Carbon Fiber Fabricated by an Innovative Manufacturing Process by using aromatic polymer on Life Cycle Greenhouse Gas Emissions” by Kotaro Kawajiri et al., describe the inventory analysis was conducted to estimate cradle-to-gate GHG emissions of AP CFs compared with the conventional production process of CFs manufactured from PAN. The results displayed that GHG emissions of AP CFs were reduced by 11% compared with the conventional PAN CFs, and further, it was reduced by 42% by a large tow production process. The objective and justification of the work are clear, and the experimental work is significant. Therefore, I recommend it for publication. However, certain Major issues are detailed below which need to be addressed before its final acceptance in Sustainability.
Comment 1: There are so many typographical errors in the manuscript text, authors must check typos, use of is, are, was, were, and preposition.
Comment 2: The abstract is poorly written, should be edited. It must summarize well the obtained results.
Comment 3: In the introduction section add some more recent literature to strengthen the section.
Comment 4: Include the Graphical Abstract for the manuscript.
Comment 5: All the Figures resolution is very poor, So, Improve the Figures Resolution.
Comment 6: Results and Discussion section should be discussed wider with some more literature support.
Comment 7: The conclusions section is too short, the authors should revise it.
Comment 8: The reference style is not maintained uniformly, so maintain the reference style uniformly.
Author Response
Response to Reviewer 2.
Please see attached for my Response to Reviewer 2.
Author Response File: Author Response.docx
Reviewer 3 Report
Authors covered important aspect of sustainable manufacturing process, namely carbon fibers as promising light-weighting material and their production in more efficient way by terms of energy production during the production and GHG emissions.
Since text needs only minor changes, I'll list them in comments below:
- literature list in references is too short. This can be improved by acknowledgement of other published work that points at the same issue.
- related to first comment, the proposed improvement in CF production process should be put into context of existing examples of (desireably commercial) implementation projects. Special attention should be put on technological readiness level and on economic feasibility of similar studied processes.
Author Response
Response to Reviewer 3.
Please see attched for my Response to Reviewer 3.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear Authors,
the paper has been improved following the indications of the reviewers. It is recommended to add the following paper in the state of the art:
Interactive optimization of the resin transfer molding using a general-purpose tool: a case study; International Journal on Interactive Design and Manufacturing Volume 14, Issue 1, Pages 295 - 3081 March 2020
Author Response
The requested reference was used in Introduction section with the citation number [3].
Reviewer 2 Report
The manuscript has been revised well according to the reviewer concerns and the provided responses are convincing. It can be considered for publication in its current form.
Author Response
Thank you for your wonderful comments
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Dear author,
the evaluation of impact of Carbon Fiber is an interesting topic, but it is necessary to investigate the problem correctly.
the paper proposes an assessment of environmental impacts without following the regulations of LCA methodology.
The method is not adequately described
The functional unit, system boundaries, reference flow are not adequately described.
The inventory is not present and the origin of the data is not clear
There is no discussion of the results
Reviewer 2 Report
This study calculated the greenhouse gas emissions of the production of new carbon fiber by considering the effect of mass production. The LCA of this process has not been reported, and this paper has academic novelty. However, the input/output data of the manufacturing processes is not presented, and transparency is low. The data on which the calculations are based, such as electricity consumption and raw material usage, should be presented. In addition, the basis for the values used in the calculations, such as carbonization efficiency, is unclear. Either a citation should be provided or it should be clearly stated whether it is based on some kind of calculation or experiment. If it is an assumption made by the authors, a sensitivity analysis should be conducted. Without these data, the validity of the data cannot be confirmed. Also, the reader cannot reuse the data. The disclosure of the unit process data and the method of preparing each data should be carefully described.