Environmental Impact Analysis of Portland Cement (CEM1) Using the Midpoint Method
Round 1
Reviewer 1 Report
The article presents important issues related to cement production in the context of environmental protection. The topicality of the topic of the article should be emphasized, as cement is the most common material used in construction. Its use is at the highest level among all building materials.
The authors presented their analyses on the example of original data obtained and compiled in South Africa. For this purpose, the Life Cycle Assessment (LCA) method was used, and a detailed analysis was developed in the specialized SimaPro 9.1.1 software.
Development: methodology, method of carrying out the analysis, presentation of the results together with the analysis can be treated very universally. The Authors' approach to the described issues is correct and covers most of the possible elements. It is understandable that, in the assumptions for the analysis, other aspects are also possible, but this is the law of any scientific-research work.
In the opinion of the reviewer, the set of assumptions presented in this paper as well as the analysis itself together with their assessment are correct and have a sufficient strength of "environmental validity".
The only remark that may have a slight impact on the conducted analyzes (LCA and LCIA) is the proposed literature database presented in line number 116 [item 44 and 45], where the authors present ISO standards from 2006. The available standards from 2009 have slight changes in some of the analyzed elements. I recommend checking these issues in order to increase the timeliness of the study.
Author Response
Point 1: The only remark that may have a slight impact on the conducted analyzes (LCA and LCIA) is the proposed literature database presented in line number 116 [item 44 and 45], where the authors present ISO standards from 2006. The available standards from 2009 have slight changes in some of the analyzed elements. I recommend checking these issues in order to increase the timeliness of the study.
Response 1: The available standard from 2009 (ISO/TS 14072:2014) has been included in the manuscript. Page 3, lines 119-123, 136-138; page 6, lines 243-244
Author Response File: 
Author Response.docx
Reviewer 2 Report
Please rewrite the abstract, showing the practical relevance of the results of the study. Abstract should be included such information about research: Purpose. Methods. Findings. Practical value.
Line 14 in the abstract has a colon at the end of the sentence.
After the first section of the Introduction, it is necessary to indicate the purpose and tasks of the study. Example: “The work aims to …. To achieve this aim, the following tasks were set: ...”
It is not clear why there is a separate section for the Life Cycle Assessment? I recommend substantiating why the methodology of LCA was chosen in this work to be placed in the Methodology section, which is more logical.
The numbering of formulas is wrong, formula (1) is followed by formula (3) and then formula (3) again. In addition, the formulas are incorrectly displayed.
It is necessary to justify in the Results and Discussion section what was new in this study in comparison with previous works. Please note what the new results did you obtain? or some new applications of previous work, verification of previous work, an improvement on previous work?
The conclusions provide general recommendations for the implementation of energy efficient technologies and on-site energy recovery technologies. It would be worth to detail them and form recommendations on the directions of implementation of such technologies at specific stages of Portland
cement production, taking into account the results of LCA and the Recipe 2016 v 1.04 midpoint method.
Author Response
Response to Reviewer 2 Comments
Point 1: Please rewrite the abstract, showing the practical relevance of the results of the study. Abstract should be included such information about research: Purpose. Methods. Findings. Practical value.
Response 1: The abstract has been revised in the manuscript. The information about research & the summary of the results is included. Page 1
Point 2: Line 14 in the abstract has a colon at the end of the sentence.
Response 2: This has been noted and corrected in the manuscript. Page 1, line 13
Point 3: After the first section of the Introduction, it is necessary to indicate the purpose and tasks of the study. Example: “The work aims to …. To achieve this aim, the following tasks were set: ...”
Response 3: The aim of the study has been included at the end of the introduction section. Page 4, lines 168-171
Point 4: It is not clear why there is a separate section for the Life Cycle Assessment? I recommend substantiating why the methodology of LCA was chosen in this work to be placed in the Methodology section, which is more logical.
Response 4: This section has been reversed in the manuscript. Page 3
Point 5: The numbering of formulas is wrong, formula (1) is followed by formula (3) and then formula (3) again. In addition, the formulas are incorrectly displayed.
Response 5: The equations figures have been corrected and numbered. Page 8
Point 6: It is necessary to justify in the Results and Discussion section what was new in this study in comparison with previous works. Please note what the new results did you obtain? or some new applications of previous work, verification of previous work, an improvement on previous work?
Response 6: This has been added in the results and discussion section. Page 10, line 373-376; page 11, lines 385-387; page 12, lines 416-418.
Point 7: The conclusions provide general recommendations for the implementation of energy efficient technologies and on-site energy recovery technologies. It would be worth to detail them and form recommendations on the directions of implementation of such technologies at specific stages of Portland cement production, taking into account the results of LCA and the Recipe 2016 v 1.04 midpoint method.
Response 7: This has been acknowledged and details were made accordingly. Page 14, lines 510-538.
Author Response File: Author Response.docx
Reviewer 3 Report
Review Assignment for energies-1622776:
This is a comprehensive study on the LCA of cement production. I believe it is very helpful for researchers and producers to identify the potential improvements spots in this industry. Overall, the paper is well written and well gathered the required information. As a reader, I was almost convinced by the amount of information provided to me to understand each analysis part. There are some minor additions that I request to consider for a final touch. I hope the authors apply this revision on their paper since I see good potential in this paper to be published after revisions. Here are my comments:
- On page 5, line 232, what are the cradle to gate stages in the study? It sounds like it needs a bit more explanation or maybe some figure labeling.
- On page 4, line 138, these references have worked very well on the environmental assessment and human health impact and could be cited to support the statement. [Developing Guidelines for Assessing the Effectiveness of Intelligent Compaction Technology] and [Preliminary evaluation of using intelligent compaction for life cycle assessment and life cycle cost analysis of pavement structures]
- Could you please explain the role of steel consumption in cement production?
- On page 4, line 146, the authors could add the following explanation to show how material replacement can lead to a more efficient concrete production:
“For instance, reduction of cement proportion in concrete and addition of different cementitious materials such as pumice, zeolite, fly ash, metakaolin, and nanomaterials has shown strong improvements in fresh properties, mechanical strength, and durability of concrete productions” [Characterizing fiber reinforced concrete incorporating zeolite and metakaolin as natural pozzolans], [Strength optimization of cementitious composites reinforced by carbon nanotubes and Titania nanoparticles], [Evaluating the Use of Recycled and Sustainable Materials in Self-Consolidating Concrete for Underground Infrastructure Applications], [One-step random-walk process of nanoparticles in cement-based materials], [Experimental studies on rheological, mechanical, and microstructure properties of self‐compacting concrete containing perovskite nanomaterial], [A comprehensive experimental study on the performance of pumice powder in self-compacting concrete (SCC)], [Effect of pre-coating lightweight aggregates on the self-compacting concrete].
- How is transportation differentiated from fuel consumption in fig 4 and 5?
In the present form of the paper, my decision is a minor revision. However, I would be glad to review the article after the authors’ revision.
Author Response
Response to Reviewer 3 Comments
Point 1: On page 5, line 232, what are the cradle to gate stages in the study? It sounds like it needs a bit more explanation or maybe some figure labeling.
Response 1: Highlights have been included. Cradle-to-gate, including the acquisition of raw material, transportation (within the plant) and production stages. Page 6, line 255-256.
Point 2: On page 4, line 138, these references have worked very well on the environmental assessment and human health impact and could be cited to support the statement. [Developing Guidelines for Assessing the Effectiveness of Intelligent Compaction Technology] and [Preliminary evaluation of using intelligent compaction for life cycle assessment and life cycle cost analysis of pavement structures]
Response 2: The suggested references have been included in the manuscript. Page 4, line 147
Point 3: Could you please explain the role of steel consumption in cement production?
Response 3: The role of steel in cement production has been added to the manuscript. Page 4, lines 159-166
Point 4: On page 4, line 146, the authors could add the following explanation to show how material replacement can lead to a more efficient concrete production:
"For instance, reduction of cement proportion in concrete and addition of different cementitious materials such as pumice, zeolite, fly ash, metakaolin, and nanomaterials has shown strong improvements in fresh properties, mechanical strength, and durability of concrete productions" [Characterizing fiber reinforced concrete incorporating zeolite and metakaolin as natural pozzolans], [Strength optimization of cementitious composites reinforced by carbon nanotubes and Titania nanoparticles], [Evaluating the Use of Recycled and Sustainable Materials in Self-Consolidating Concrete for Underground Infrastructure Applications], [One-step random-walk process of nanoparticles in cement-based materials], [Experimental studies on rheological, mechanical, and microstructure properties of self‐compacting concrete containing perovskite nanomaterial], [A comprehensive experimental study on the performance of pumice powder in self-compacting concrete (SCC)], [Effect of pre-coating lightweight aggregates on the self-compacting concrete].
Response 4: The suggested statement by the reviewer with the reference has been included in the manuscript. Page 4, line 156-159
Point 5: How is transportation differentiated from fuel consumption in fig 4 and 5?
Response 5: The manuscript has been corrected according to the reviewer's comment. Page 12, lines 436-440; page 13, lines 462-470
Author Response File: Author Response.docx
