Analysis of Carbon Emissions and Emission Reduction from Coal-Fired Power Plants Based on Dual Carbon Targets

Round 1

Reviewer 1 Report

This study constructs a carbon emissions calculation model and carbon emissions data accounting model for coal-fired power plants, and carries out example data calculation and carbon emission reduction analysis. This is a meaningful study in the process of realizing the goal of double carbon in China.

Specific content:

1. Please introduce the China's dual carbon goals in “Intrduction” section.

2. “Jia K proposed an innovative mechanism to address the dual carbon target, thus providing suggestions...”, What is the suggestion?

3. Please double check if Equations are correct.

4. Please introduce the carbon emissions calculation model in Section 3.1.

5. What is the significance of accounting modeling based on carbon-sensitive analysis? (Section 3.2)

6. In the coal-fired power plant example, CO2 emissions generated during the combustion of fossil minerals or coal?

7. “Based on this, the study analysed the turbine side and boiler side data under different operating conditions”, The operating conditions must be clearly described.

Author Response

This study constructs a carbon emissions calculation model and carbon emissions data accounting model for coal-fired power plants, and carries out example data calculation and carbon emission reduction analysis. This is a meaningful study in the process of realizing the goal of double carbon in China.

Specific content:

1. Please introduce the China's dual carbon goals in “Intrduction” section.

Reply: Thank you very much for your comments. China's dual carbon goals are added in “Intrduction” section of the revised paper.

"Double carbon" is the abbreviation of carbon peak and carbon neutral synthesis. In 2020, China explicitly proposed to achieve the dual carbon goal, that is, by 2025, the proportion of non mineral energy consumption will be increased to 20%, the energy consumption per unit of gross domestic product (GDP) will be reduced by 13.5%, and the CO2 emission per unit of GDP will be reduced by 18%. By 2030, the proportion of non mineral energy consumption will be 25%, and the CO2 emission per unit of GDP will be reduced by 65%.

2. “Jia K proposed an innovative mechanism to address the dual carbon target, thus providing suggestions...”, What is the suggestion?

Reply: Thank you very much for your comments. The suggestion is added in the revised paper. As follows:

Jia K analyzes the innovation mechanism of the dual carbon target based on relevant issues, thereby providing assistance for the construction of response mechanisms in the overall development form of the dual carbon target.

3. Please double check if Equations are correct.

Reply:Thank you very much for your comments. Wechecked all the formulas in the manuscript and they are correct.

4. Please introduce the carbon emissions calculation model in Section 3.1.

Reply: Thank you very much for your comments. The carbon emission calculation model you mentioned in the article is essentially a mathematical model for parameter sensitivity calculation and a data accounting model, which I have described in the manuscript. In addition, perhaps the descriptions of some sentences in the article have misled you, and I have also revised them, such as the setence “Case data calculations and carbon emission reduction analysis were conducted” in the revised paper.

5. What is the significance of accounting modeling based on carbon-sensitive analysis? (Section 3.2)

Reply: Thank you very much for your comments. It is precisely because of the sentence description that the article chapters have misled you. In essence, the calculation model contains the data accounting model in section 3.2. Therefore, section 3.2 is both the content of the calculation model and a supplement to the mathematical calculation model for carbon sensitivity analysis.

6. In the coal-fired power plant example, CO2 emissions generated during the combustion of fossil minerals or coal?

Reply: Thank you very much for your comments. The carbon dioxide emissions during coal combustion are added in the revised paper. At the same time, the statement description issueshave also been revised. As follows:

At the same time, taking coal-fired power plants as an example, carbon and sulfur pollutants are inevitably generated during coal combustion, while the gas is mainly CO2. The main processes include coal water conversion reaction, Fischer Tropsch reaction, methanation reaction, and disproportionation reaction.

In the experiment, the research took a coal-fired power plant in Inner Mongolia Autonomous Region of China as the analysis object, and the specific research contents were CO2 emissions generated during coal combustion, CO2 emissions in desulfurization projects, and CO2 emissions generated during power procurement and use in the factory.

7. “Based on this, the study analysed the turbine side and boiler side data under different operating conditions”, The operating conditions must be clearly described.

Reply: Thank you very much for your comments. Based on your comments, the operating conditions are described in the revised paper as follows

On this basis, the research analyzed the data of the steam turbine side and the boiler side under the operating conditions of 60%, 75%, and 90% load rates, and the results are shown in Figure 5.

 

In addition, the whole manuscript is checked to avoid grammatical and spelling mistakes.

 

Reviewer 2 Report

This study constructs a calculation model and data accounting model for carbon emissions from a power plant. The paper is interesting and it proposes some available suggestion to reduce carbon emission in coal-fired power plants. Below are some comments to help improve the quality of the paper. 

1. In the section of “Literature review”: Why was coal-fired power plant chosen as the research object? It was not explained in the paper.

2. The combination of the sections of “Introduction” and the section of “Literature review” may be more beneficial to the reader.

3. Please provides the source or reference of the formula used in the manuscript.

4. “Within smoke temperature model, the other parameters are set constant...”, What other parameters are?

5. Please reorganize the sentence of “the low level heat content of the fuel, carbon content and oxidation rate in unit calorific value”.

6. Why the loading rate of 90% was analyzed separately?

7. “For a coal-fired power plant alone” can be changed to “In terms of a single coal-fired power plant”.

8. What do "Unit 1" and "Unit 2" stand for? Please introduce them.

9. The English grammar of this manuscript needs to be improved.

Author Response

This study constructs a calculation model and data accounting model for carbon emissions from a power plant. The paper is interesting and it proposes some available suggestion to reduce carbon emission in coal-fired power plants. Below are some comments to help improve the quality of the paper. 

1. In the section of “Literature review”: Why was coal-fired power plant chosen as the research object? It was not explained in the paper.

Reply: Thank you very much for your comments. The reasons for choosing coal-fired power plants as the research object is added in the literature review section. As follows:

Considers the principles of operational parameter controllability and the actual conditions of carbon accounting,

2. The combination of the sections of “Introduction” and the section of “Literature review” may be more beneficial to the reader.

Reply: Thank you very much for your comments, and I am very sorry that the introduction and literature review of this article cannot be combined. The main reason is that the introduction is introduced as a research background for the purpose of research, while the literature review is introduced into current research at home and abroad, and the two complement each other. Sorry again.

3. Please provides the source or reference of the formula used in the manuscript.

Reply: Thank you very much for your comments. Thereference is added in the revised paper.

Zhang, X., Dou, Y., Zhang, C., Ding, L., Lv, H. (2023). Carbon emission management of coal power plant from the perspective of production planning in China. Journal of Industrial and Production Engineering, 40(1), 22-34. https://doi.org/10.1080/21681015.2022.2116494

4. “Within smoke temperature model, the other parameters are set constant...”, What other parameters are?

Reply: Thank you very much for your comments. Other parameters are smoke content parameters, carbon content parameters of fly ash, etc.

5. Please reorganize the sentence of “the low level heat content of the fuel, carbon content and oxidation rate in unit calorific value”.

Reply: Thank you very much for your comments. The setence is changed to “In the field of fossil fuel combustion emissions, research is conducted to determine the CO2 emissions of fossil fuels based on the amount of combustion of the fuel type, the actual calorific value of the lower fuel level, the carbon content in the unit calorific value, and the oxidation rate.”

6. Why the loading rate of 90% was analyzed separately?

Reply: Thank you very much for your comments. Perhaps the description in the article is misleading. In fact,the load rates of 60%, 75%, and 90% are also analyzed. See below:

On this basis, the research analyzed the data of the steam turbine side and the boiler side under the operating conditions of 60%, 75%, and 90% load rates, and the results are shown in Figure 5.

7. “For a coal-fired power plant alone” can be changed to “In terms of a single coal-fired power plant”.

Reply: Thank you very much for your comments. The setence is changed to “In terms of a single coal-fired power plant”.

8. What do "Unit 1" and "Unit 2" stand for? Please introduce them.

Reply: Thank you very much for your comments. The two coal-fired power generating units you mentioned, Unit1 and Unit2, may have some omissions in the sentence. This comment is revised in the revised paper.

9. The English grammar of this manuscript needs to be improved.

Reply: Thank you very much for your comments. The whole manuscript is checked to avoid grammatical and spelling mistakes.

 

 

 

Reviewer 3 Report

The comments are in the attached file.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

 

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

 

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

 

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

 

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figurFor ALL the equations and parameters there is lack of units, thus the reviewer has to guess what do the authors want to calculate…. The model equations have to be explained and the units given.

Line 104 – what is ‘per unit standard’? Line 109: What is ‘power supply coal loss’. Correct that and check English, please.

What is the message from Figs. 2 and 3? I do not understand why you need a figure for that?

No explanation of the results in FIg. 4a-b. What were the assumptions? Also in Fig. 4: The axis are wrong – please correct. For example: the term ‘Load rate’ has a unit of [%/s] since it is a rate. The description of the values is poor, why only loads of 60%, 75% and 90% were chosen? Not explained. The same comments refer to Fig. 5 – please correct the axis, caaptions and explain the results.

Fig. 4c – explain the numers 1-7 and correct the axis captions (‘axis serial nimber’? What is it?.

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

The authors’ goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

The language should be chcecked and some phrases should be modiifed to make tchem clear:, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]…..

37-39: the statement is vague – correct.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

Line 366-367: the statement is obvious.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

Comments for author File: Comments.pdf

Author Response

The authors goals seem to be interesting but the paper is not logically written in the current form and has to be revised before publication. My comments and suggestions for corrections are as follows:

The title should be modified – what is ‘dual-carbon background’?

Reply: Thank you very much for your comments. The title was changed to“Analysis of carbon emissions and emission reduction from coal-fired power plants based on dual carbon targets”.

dual carbon, namely carbon peak and carbon neutral for short.

The language should be checked and some phrases should be modified to make them clear, e.g. lines 14-15 ‘carbon sensitivity of the inside of the boiler’ and elsewhere.

Reply: Thank you very much for your comments. Multiple statements in the research have been revised. Such as:

The carbon sensitivity of the inner side of the boiler under control conditions is higher than that of the operating parameters controlled on the inner side of the steam turbine.

Lines 27-28: lack of citation, furthermore more info on ‘double carbon’ is needed.

Reply: Thank you very much for your comments. A citation has been added to this sentence. As follows:

YU, G., HAO, T., & ZHU, J. (2022). Discussion on action strategies of China’s carbon peak and carbon neutrality. Bulletin of Chinese Academy of Sciences (Chinese Version), 37(4), 423-434. https://doi.org/10.16418/j.issn.1000-3045.20220121001

Please correct the names of authors by deleting the initials and put the citation right after the names – do it for whole manuscript text (e.g. Cabernard et al. [6]……

Reply: Thank you very much for your comments. Based on your suggestion, the author's initials have been removed and the citation number has been placed after the author's name.

37-39: the statement is vague – correct.

Reply: Thank you very much for your comments. Based on your suggestion, this sentence has been revised. See below:

The "dual carbon" strategy advocates a green and low-carbon lifestyle, and accelerating emission reduction is an important measure to promote green technology innovation and enhance the international competitiveness of industry and economy. Therefore, implementing reasonable carbon reduction methods under the dual carbon goals has become particularly important. An Y et al.[4] built a carbon emission reduction calculation model on the basis of Data envelopment analysis for carbon emission potential and other related issues.

Delete the statements like ‘melancholy thought’ (line 63) – it is a technical paper not lyrics.

Reply: Thank you very much for your comments. Based on your suggestion, 'moderately thought' has been reasonably deleted. See below:

Booth M S [20] has proposed measures related to energy transfer to address the issue of countries around the world being overly reliant on Russian oil, providing recommendations for upper level policies to implement carbon reduction.

Fig. 1 – what is the message? What are the differences between the first and second level relationships? Not explained completely. The caption is also quite vague – correct or delete the figure.

Reply: Thank you very much for your comments. Based on your suggestion, the relevant explanations have been added to Figure 1. As follows:

The difference between the two is that the former calculates the variation relationship based on efficiency, while the latter calculates the variation relationship based on specific parameters. By combining these two steps, the calculation formula between the changes in various parameters and the changes in carbon emission intensity can be obtained.

What kind of power plant is it – at least some main data like total power, coal data, coal consumption, emission limits, boiler type, should be presented BEFORE you present the results! General rule: first present the plant and data, and then the model and results otherwise it is illogical.

Reply: Thank you very much for your comments. Based on your suggestion, some data of the power plant has been added to the research. See below:

Meanwhile, its boiler type is a natural circulation single furnace with a capacity of 1025t/h; The total power is 600MW; The emission limits for smoke, SO2, and NOx shall not exceed 5, 35, and 50mg/m³, respectively.

For ALL the equations and parameters there is lack of units, thus the reviewer has to guess what do the authors want to calculate… The model equations have to be explained and the units given.

Reply: Thank you very much for your comments. The relevant parameter units in the equation have been added to the revised paper.

Line 104 – what is ‘per unit standard’? Line 109: What is ‘power supply coal loss’. Correct that and check English, please.

Reply: Thank you very much for your comments. The English words have been revised. Such as:

unit standard

represents coal loss in power supply

What is the message from Figs. 2 and 3? I do not understand why you need a figure for that? No explanation of the results in Fig. 4a-b. What were the assumptions? Also in Fig. 4: The axis are wrong – please correct. For example: the term ‘Load rate’ has a unit of [%/s] since it is a rate. The description of the values is poor, why only loads of 60%, 75% and 90% were chosen? Not explained. The same comments refer to Fig. 5 – please correct the axis, captions and explain the results.

Reply: Thank you very much for your comments. Figures 2 and 3 have been deleted based on your feedback. The results of Figure 4 (a) and Figure 4 (b) (now Figure 2) have been explained. The title of Axis 4 in Figure is a translation error and has been modified. Meanwhile, an explanation of the reasons for selecting these three load rates has been added to the text, and the title of the axis in Figure 5 (now Figure 3) has been modified and the results have been explained.

Figures 2 (a) and 2 (b) comprehensively demonstrate that factory electricity has higher carbon sensitivity under low operating conditions.

Due to the consideration of practical stability and the need for realistic conditions, the study only considered three stable operating conditions: 60%, 75%, and 90% load factors. At the same time, to more clearly see the common range of changes in various controllable operating parameters in actual operation, a separate analysis was conducted on the 90% load factor.

It indicates that the carbon sensitivity of plant electricity consumption is relatively high under low operating conditions.

Fig. 4c – explain the numers 1-7 and correct the axis captions (‘axis serial number’? What is it?

Reply: Thank you very much for your comments. The numbers 1-7 in Figure 4 (c) have been explained, and the axis title has been modified. As follows:

Lines 253-265: correct the values there, e.g. temperature is not in [W]… Also the value of 5.581 g/kWh is not clear from the figure – explain.

Reply: Thank you very much for your comments. The values have been modified.

29.77 g/MJ.

Fig. 6: Why the coal consumption was reduced in 2021-2019 compared to 2018 (Fig. 6a)? Wrong numerical values for the description of X axis. Simple show the values without and ‘numericals’

Reply: Thank you very much for your comments. The explanation for the lower coal consumption from 2019 to 2021 compared to 2018 in Figure 6 (a)(now Figure 4) has been added to the study. Meanwhile, the X-axis of Figure 6 has been revised.

Due to the proposal to achieve the dual carbon goals and implement carbon reduction strategies, the total coal consumption in the past four years has remained roughly between 1.8 million tons and 2 million tons, with a decreasing trend.

Fig. 7: What do the colors of the bars of Fig. 7a represent? Not shown. Also correct the axis descriptions. Also the values you refer in the text do not correspond (or are difficule to follow) with the numbers in the figures.

Reply: Thank you very much for your comments. A legend has been added to Figure 7 (now Figure 5) and the axis has been changed. At the same time, the text reference value has been corresponding to the numbers in the figure.

Explain the values in Table 1 in the table – not below since it is difficult to read.

Reply: Thank you very much for your comments. The explanations for each element in Table 1 have been revised in the table.

Particular year	2018	2019	2020	2021
Annual average carbon content per unit calorific value of coal (t/TJ)	26.3	27.8	28.1	28.2
Annual production of boiler residue /t	3548.5	2686.7	2248.2	2548.1
The average carbon content level of residue in the boile /%	0.8	0.5	1.1	1.2
Annual fly ash production /t	31936.3	24181.1	20234.0	22931.4
Average carbon content of fly ash /%	0.4	0.5	0.9	1.0
Efficiency of dust collectors/%	99.9	99.9	99.9	99.9
Probability of oxidation of coal carbon during combustion/%	99.6	99.8	99.7	99.5

Correct the axis in Fig. 8. What probability do the authors mean?

Reply: Thank you very much for your comments. The axis of Figure 8 (now Figure 6) has been revised.

Table 2: correct the statements, like ‘Grandma generral’, ‘Carbon oxidation rate’ – what is it? Also the CO2 emission should be given in ‘t/MWh’ – then we could compare. Showing the total emission [t] has no message since it cannot be directly compared.

Reply: Thank you very much for your comments. The first word is incorrect and has been revised in the text. The carbon oxidation rate refers to the rate at which carbon in the fuel is oxidized into carbon dioxide during the combustion process, and this explanation has been added to the text. Meanwhile, 'carbon dioxide emissions' is a part of speech interpretation error and should be' carbon dioxide emissions from coal-fired combustion ', therefore its unit is't', which has been revised in the text.

Annual average low calorific value of raw coal (kJ/kg^-1)

Carbon dioxide emissions from coal-fired combustion(t)

The carbon oxidation rate in Table 2 refers to the rate at which carbon in the fuel is oxidized to carbon dioxide during the combustion process.

Fig. 9: Correct axis caption – what probability do they mean? Also, the explanation text should always be before the Figure, not after.

Reply: Thank you very much for your comments. The axis title in Figure 9 (now Figure 7) has been revised. At the same time, the text explanations for all the results in the figure have been placed in front of the figure.

Line 366-367: the statement is obvious.

Reply: Thank you very much for your comments. These two lines, including the conclusion, have been revised. See below:

To better understand the company's carbon emissions, a carbon emission calculation model and carbon emission data accounting model for coal-fired power plants were studied and constructed, and case data calculations and carbon emission reduction analysis were conducted. The experimental results show that in the carbon emission parameter sensitivity experiment, the efficiency of the inner side of the boiler is higher than the absolute internal efficiency of the steam turbine at different load rates. At a load rate of 60%, for every 1MW reduction in factory power consumption,  will decrease by 29.77 g/MJ. In addition, the emission factor of coal-fired power has averaged 100.806t/TJ in the past four years and is gradually increasing, reaching a maximum of 102.80 t/TJ. In the coal-fired carbon emission experiment, the fitting degree between the carbon emissions of Unit 1 and Unit 2 was less than 2%, indicating the accuracy of the experimental data. Finally, in the carbon emission reduction analysis experiment, taking 2018 as an example, for every 1.58 g/MJ reduction in coal consumption while maintaining the same power supply, 4300 tons of carbon dioxide can be reduced. Overall, under low load conditions, power plants exhibit a high level of carbon sensitivity, indicating significant potential for carbon dioxide reduction. At the same time, reducing the carbon content in fly ash can reduce electricity consumption and achieve carbon emissions reduction. However, the data collected in the study is measured in years, which can affect the accuracy of the results, so data can be collected in months in the future.

The conclusions are quite vague and more attention should be put to the results of the calculations – please rewrite.

Reply: Thank you very much for your comments. The conclusion has been revised. As follows:

To better understand the company's carbon emissions, a carbon emission calculation model and carbon emission data accounting model for coal-fired power plants were studied and constructed, and case data calculations and carbon emission reduction analysis were conducted. The experimental results show that in the carbon emission parameter sensitivity experiment, the efficiency of the inner side of the boiler is higher than the absolute internal efficiency of the steam turbine at different load rates. At a load rate of 60%, for every 1MW reduction in factory power consumption,  will decrease by 29.77 g/MJ. In addition, the emission factor of coal-fired power has averaged 100.806t/TJ in the past four years and is gradually increasing, reaching a maximum of 102.80 t/TJ. In the coal-fired carbon emission experiment, the fitting degree between the carbon emissions of Unit 1 and Unit 2 was less than 2%, indicating the accuracy of the experimental data. Finally, in the carbon emission reduction analysis experiment, taking 2018 as an example, for every 1.58 g/MJ reduction in coal consumption while maintaining the same power supply, 4300 tons of carbon dioxide can be reduced. Overall, under low load conditions, power plants exhibit a high level of carbon sensitivity, indicating significant potential for carbon dioxide reduction. At the same time, reducing the carbon content in fly ash can reduce electricity consumption and achieve carbon emissions reduction. However, the data collected in the study is measured in years, which can affect the accuracy of the results, so data can be collected in months in the future.

Reviewer 4 Report

Comments for author File: Comments.pdf

Author Response

Notes on “Analysis of carbon emission…”

The following points have been noticed:

1) English writing should be reviewed. For instance, in the Abstract the following is found: “…this study constructs a carbon emissions calculation model and carbon emissions data…” Better to write: “…this study constructs a carbon emission model and carbon emission data…”

Reply:Thank you very much for your kind comments. The whole manuscript is checked to avoid grammatical and spelling mistakes. And the setence was changed to “To enable enterprises to better understand their carbon emissions, this study constructs a carbon emission model and carbon emission dataaccounting model for coal-fired power plants, Case data calculations and carbon emission reduction analysis were conducted.”

2) The authors should avoid industrial jargon such as “carbon sensitivity”. Use scientific and precise nomenclature. Please, they should explain the meaning of “carbon sensitivity.”

Reply: Thank you very much for your kind suggestion. 'Carbon Sensitivity' is scientific and precise nomenclature. In order not to affect your reading, according to your kind suggestion, the definition of its term has been added to the text. As follows:

Carbon sensitivity refers to the sensitivity of a company's business, assets, and strategies to carbon emissions and climate change risks.

3) Preferably, use SI units. For example, instead kW h use MJ or even GJ. They may leave the number in kW h between brackets after the value in GJ. Remember that 1 kW h is 3.6 MJ.

Reply: Thank you very much for your comments. The corresponding units in the text were changed to the international units.

4) Again, do not use jargons such as “…protecting people's green homes…” What exactly that means? The authors must use scientific and precise technical language.

Reply: Thank you very much for your kind comments.The sentence has been revised to:

The "double carbon" strategy advocates a green and low-carbon lifestyle. Accelerating emission reduction is an important step to promote green technology innovation and enhance the international competitiveness of industry and economy.

5) At lines 33 to 35, the authors wrote: “Xue X et al. proposed technologies related to mixed combustion of biomass and carbon dioxide capture and collection in order to achieve zero carbon emissions.” The mixing of biomass and coal is a very known idea to reduce overall carbon emission, however, except in the case that just biomass is used as fuel, any introduction of coal in the mixture would lead to a degree of overall carbon emission to the ambient it. The statement made by the authors is not only false and may only serve to impress a naïve or non-technical audience. This jeopardizes the scientific seriousness of their work.

Reply: Thank you very much for your comment. The description of this reference has been revised. As follows:

Xue X et al. proposed technologies related to biomass hybrid combustion and CO2 capture and collection to achieve zero carbon emissions.

6) At lines 78 and 79, the following is found: “Therefore, for the sake of ensuring that 79 the carbon emission concentration of the unit reaches…” What is carbon emission concentration? I think that they mean “rate of carbon dioxide emission”. The work lacks precise language.

Reply: Thank you very much for your comments, and I am also very sorry for the inconvenience caused. The sentence was changed to “Therefore, in order to ensure that the unit's carbon dioxide emission rate reaches a low carbon level”.

Carbon sensitivity refers to the degree to which carbon emission intensity reacts to actual changes in various parameters.

7) The meaning of each variable is explained after each equation without measuring units. Those should be put in a nomenclature table with the corresponding SI units.

Reply: Thank you very much for your comments. Based on your comments, the nomenclature of international units were added to the introduction section of the revised paper. In addition, there is an explanation of the meaning of variables behind each formula in the revised paper.

Name	International Units
Carbon emission intensity	kgCO2/IntGK $
Temperature	K
Volume	m3
Specific heat capacity	J /(kg·K)
Quantity of heat	J
Absolute humidity	g/m3
Calorific value	MJ

8) Please, justify the first line of Equation 5. Why have all efficiencies been assumed equal? That is a very strong assumption.

Reply: Thank you very much for your comments. Based on your comments, I have introduced a document to illustrate the first line of Formula 5.

The reference:

Panchal, D., Chatterjee, P., Pamucar, D., & Yazdani, M. (2022). A novel fuzzy‐based structured framework for sustainable operation and environmental friendly production in coal‐fired power industry. International Journal of Intelligent Systems, 37(4), 2706-2738.

9) Figure 2 is too simplistic and naïve for a manuscript submitted to an international technical and scientific journal. It leaves the impression that the authors wrote an article for a popular information magazine.

Reply: Thank you very much for your comment. Now, the Figure 2 in the original paper was deleted.

10) At line 146, the authors refer to “smoke temperature”. What exactly does that mean? They should be referring to flue gas temperature or average temperature of the gas leaving the power unit chimney or chimneys.

Reply: Thank you very much for your comments. The flue gas temperature mentioned here refers to the temperature of the flue gas at the outlet of the boiler flue. Perhaps the statement is misleading. See delow:

In the smoke exhaust temperature model, if other parameters are set unchanged, the smoke exhaust temperature changes.

11) Likewise Figure 2, Figure 3 is simplistic and not worthy of been used in a serious technical paper.

Reply: Thank you very much for your comment. The Figures 2 and 3in the original paper were deleted.

12) At line 254 the authors refer again to “smoke temperature” but using the units of power (W). Please, explain.

Reply: I am so sorry for the mistake. Now, it was changed to K in the revised paper.

13) The phrase from line 253 to 258 is very unclear. It should be carefully edited. Actually, the whole manuscript should be edited.

Reply: Thank you very much for your feedback. The phrase has been revised. At the same time, the entire text was reviewed and revised. For example:

In the experiment, the research took a coal-fired power plant in the Inner Mongolia Autonomous Region of China as the analysis object, and the research content mainly included the CO2 emitted during the coal combustion process, the CO2 emitted during the desulfurization project, and the CO2 emitted during the power procurement and use of the plant.

14) Figure 9b is not clear. It is supposed to show the carbon content in the ash leaving the power unit, which is a concentration and not a probability, as indicated in the vertical coordinate. All figures should be reviewed for clarity.

Reply: Thank you very much for your comments. The Figure 9 in the original paper was revised and changed to Figure 7 in the revised paper, as follows:

Figure 7. Result of relationship between carbon content in fly ash and coal consumption for power supply.

15) Actually, the coordinates of all Figures 9 should be edited. In addition, the text after that figure is badly written. The whole manuscript should be edited for clarity.

A complete and deep rewriting is required..

Reply: Thank you very much for your comments. The Figure 9 in the original paper was revised and changed to Figure 7 in the revised paper, as follows:

In addition, the text after that figure was re-written. The whole manuscript was edited for clarity. See below:

From Figure 7, in 2018, the energy supply power was over 12.24 million MJ, and the coal consumption for power supply was 332.71 g/MJ. When the coal consumption for power supply is reduced by1.584 g/MJ, it can effectively save 2500 tons of raw coal and reduce 4300 tons of carbon dioxide, resulting in an overall carbon reduction of over 8000 tons. Therefore, reducing the carbon content in fly ash to reduce electricity consumption is an important direction for carbon reduction.

 

 

Round 2

Reviewer 3 Report

The authors improved the paper substantially. It may be published.