A Scenario Simulation of Material Substitution in the Cement Industry under the Carbon Neutral Strategy: A Case Study of Guangdong

Round 1

Reviewer 1 Report

1. Abbreviations are not recommended in the abstract.

2. The equation of fitting curve in Figure 1 is not given.

3. The fitting curve in Figure 3 is not given an equation.

4. The format of the graph in the paper should be unified.

5. The article seems to lack innovation.

6. Some sentences in the paper need to be modified.

7. The conclusion of the paper should be concise.

Author Response

Thank you for your consideration and for the comments on our manuscript. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In line 191, it is specified that the CCR for Guandong’s factory is 0.80, which situates this factory among the higher end (taking into account the 0.65 average vs. the 0.87 top-end) of CCRs worldwide. And if (as assumed in Line 245) the utilization of low-carbon raw materials is close to zero for this factory, proportionately speaking the effect is going to be greater than if a CCR of 0.65 (average) is assumed as a starting point.

In line 200, although the Delphi method is widespread and broadly accepted in the scientific community, no brief definition is offered to the reader over the method itself or the reasoning behind the selection of this method particularly.    

In line 276, Table 2, BAU is used as baseline scenario while not being defined (nor mentioned) in the previous sections as (BAU), the use of undefined acronyms might confuse readers.

In figure 3, the word “cumulated” is misspelled.

Evidently, as the replacement ratios increase also the CCR decreases, however, in terms of raw material replacement and clinker substitution the replacement ratios for red mud (70%) and steel slag (20%) are quite high. Considerations over the quality of produced cement (as mentioned in line 43 should be addressed), since the replacement limit is set by hydration, reaction, durability and shrinkage properties of the resultant product. Hence, as a first approximate step over the impact such replacement levels would have on carbon emissions this study is on point. However, when addressing environmental issues related to cement production several key factors should also be taken into account: durability (given the long-term scenarios that were used), strength and standards compliance. As expected, such studies fall out of the scope of the present work, but such considerations should be mentioned in the conclusion or the policy implications section.

Recommended literature cites regarding CO₂-eq emissions related to cement production and admixtures:

Guo, S., Li, Y., Wang, Y., Wang, L., Sun, Y., & Liu, L. (2022). Recent advances in biochar-based adsorbents for CO2 capture. Carbon Capture Science & Technology, 4, 100059. https://doi.org/10.1016/j.ccst.2022.100059

Hafez, H., Teirelbar, A., Tošić, N., Ikumi, T., & de la Fuente, A. (2023). Data-driven optimization tool for the functional, economic, and environmental properties of blended cement concrete using supplementary cementitious materials. Journal of Building Engineering, 67. https://doi.org/10.1016/j.jobe.2023.106022

Miller, S. A., Habert, G., Myers, R. J., & Harvey, J. T. (2021). Achieving net zero greenhouse gas emissions in the cement industry via value chain mitigation strategies. In One Earth (Vol. 4, Issue 10, pp. 1398–1411). Cell Press. https://doi.org/10.1016/j.oneear.2021.09.011

 

 D. Castillo, J.C. Cruz, D.L. Trejo-Arroyo, E.M. Muzquiz , Z. Zarhri, M.P. Gurrola, R.E. Vega-Azamar (2022). Characterization of poultry litter ashes as a supplementary cementitious material. Case Studies in Construction Materials, 17. https://doi.org/10.1016/j.cscm.2022.e01278.

Nahuat-Sansores, J. R., Cruz, J. C., Gurrola, M. P., & Trejo-Arroyo, D. (2022). Suitability of biochar as supplementary cementitious material (SCM) or filler: waste revalorization, a critical review. Journal Civil Engineering, 6, 12–31. https://doi.org/10.35429/JCE.2022.16.6.12.31

 

 

Author Response

We feel great thanks for your professional review work on our article. Please see the attachment

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Reviewer 3 Report

 

This study investigates the simulation of material substitution in the cement industry under the carbon-neutral strategy. The presented study is an interesting study on the reduction of CO₂ from cement production. In order for the study to be published, the following corrections must be made.

·       All abbreviations given in the study should be reviewed.

·       Line 36: The long version of the CCR should be given where it is first mentioned in the introductory part.

·       Line 90: What is IPCC? The long form must be given.

·       Line 186 and 232: “clinker-to-cement ratio (CCR)”, since the long version of this is given in the introduction, it is not necessary to give the long version again in this section.

·       “Table.1. Forecast results of clinker demand in the cement industry.” Table names should be written above the table.

·       Table 2’de BAU? The long form must be given.

·       The quality in Figure 4 is very poor. The inside of the column chart for “Raw Material Replacement” is unreadable. Also, the "x-axes" are not clearly readable. of this shape should be improved.

 

·       Unit should be written on “x and y-axes” in Figure 5.

Author Response

We feel great thanks for your professional review work on our article. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

In this manuscript, the authors simulated and analyzed the impact of two cement substitute materials on carbon dioxide emission reduction in Guangdong Province. The research has certain practical significance. However, the following problems need to be further improved.

(1) As the research background and data source of the manuscript is Guangdong Province, it is suggested to add the "case study" in the title“

(2) What does IPPC mean? The complete spelling of abbreviations or references should be given.

(3) Please explain the rationality of the selected carbon emission calculation method in Part 2.1.

(4) Please explain the reliability of the method of forecasting cement demand through a single GDP per capita. Are other factors affected? For example, national policies, population size, etc. This makes me doubt the reliability of the cement demand forecast results.

(5) Pay attention to the standardization of manuscript, such as line 131 “According to Figure 2.,”

(6) The clarity of Figure 4 must be improved.

(7) The Part 4 is more like a Discussion than a Conclusion. As a Conclusion, the content is too long and unclear.

Author Response

Thank you for your consideration and for the comments on our manuscript. Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Can be accepted.

Reviewer 4 Report

The manuscript has been greatly improved. I think the manuscript can be accepted in present form.