Analysis of Synergistic Drivers of CO2 and NOX Emissions from Thermal Power Generating Units in Beijing–Tianjin–Hebei Region, 2010–2020
, Zilin Yuan 2, Jun Yan 3, Haixu Zhang 2, Qinge Guan 4, Sheng Rao 2, Chunlai Jiang 2,* and Zhiguo Duan 5,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsCO2 and NOx emission reduction is quite clear in JJJ area from 2010 to 2020, mainly driven by end of pipe control for NOx, and energy efficiency improvement together with energy use reduction for CO2 emission reduction. In general, there is conflict bwteen NOx emission reduction and CO2 emission reduction becasue reduction of NOx could increase electricity use in plants and increase CO2 emission reduction. The reduction of Nox emission in JJJ mainly driven by action plan announced in 2013.
The driving forces selected in this paper is still questionable, both NOx and CO2 emission reduction do not have much relationship with population and GDP per capita in the period. better to select some specific factors rather these general ones.
"Among the factors affecting NOx emissions, per capita GDP and population were positively correlated, while emission coefficients, energy structure and energy intensity were negatively correlated on NOx emissions." is common sense, better to present more quantified data for them.
Energy structure change is not well reported, number of power plants were reported, but energy use by power plants, by coal and natural gas is better to be reported. CO2 emission reduction in Beijing mainly comes from shifting coal to natural gas, this is better to discussion further.
Figure 1 caption is not clear, please put each sub-figure in the caption
Conclusion session is very genaral, better to more specific.
Author Response
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Reviewer 2 Report
Comments and Suggestions for Authors
The presented paper is a comprehensive study on synergistic drivers of CO2 and NOx emissions in different regions of China.
I found the topic to be very interesting and replicable in other parts of the world but the work has some flaws that need to be sorted out before it can be published in Sustainability.
The use of English may be revised, and some minor editing done to improve the quality of the publication.
- In subsections 2.1 and 2.3 the authors declare they gathered data from over 700 power plants. First, they should decide where this text goes but avoid repetition. Secondly, since the amount of power plants is very high, it is very interesting to provide a deeper explanation about how all the data was collected, if they collected the data one by one or used a provider who gathered several databases...
- In line 115 the authors start a sentence with "2010-2020...". Please, avoid such abrupt beginnings.
- It is recommended to provide a deeper explanation on the Carbon oxidation rate and its importance for the study. Also, paragraph in lines 130 to 133 should be placed before Table 1.
- Figures 1, 8 and 9 need a larger font size as they are hard to read at the moment.
- For Figure 5, what happened in Tianjin after 2017? Why the coal surged in that way?
- What are the factors behind the high use of coal in Hebei and Tianjin in comparison with Beijing?
- For the conclusions, will energy intensity reduction benefit the decrease of CO2 and NOx emissions equally or one of them will get a higher benefit?
Comments on the Quality of English Language
Some editing may benefit the quality of the publication.
Author Response
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Reviewer 3 Report
Comments and Suggestions for AuthorsThis manuscript presented an analysis of CO2 and NOx emissions in Beijing-Tianjin-Hebei based on the available emission data, from 2010 to 2020, on thermal power units within this area and illustrated the synergistic drivers of CO2 and NOx emissions, which could potentially serve as guide for policymakers. However, the authors needs to address several issues and significantly improve the manuscript before I could recommend it for publication.
1. When the authors have multiple different plots in one figure, please explain each figure in the captions. Some figures were presented, but not mentioned in text or inadequately discussed, for example figure 1 b and c and figure 8. Missing enough explanation makes these figures confusing to readers.
2. Could the authors explain when calculate the CO2 emission, what data was used as energy consumption FCi? It's not clearly stated in the manuscript.
3. When discussing the data from figures, the authors usually use different units in the text from the figures. Could the authors make the units consistent so that the reviewers and your readers don't have to convert by themselves? For example, in line 218, the authors wrote generating capacity in billion kwh while figure 1 e used hundreds million kwh. I don't understand why the authors choose to present data this way in many different places in the manuscript.
4. Whenever you present some data like numbers, please make sure you reference the data source either from your figure plots or a cited source. For example the coal consumption data from line 226 to line 236, etc.
5. Please explain the abbreviations in Table 4 and 4. In table 5, please reasonably decrease the significant numbers.
6. Please check your citations. Many of your references were not cited in the manuscript, for example 2, 3, 5, 7, 8, 12, 21.
7. Please check for typos and inconsistency in format. For example, the authors have used "Fig." and "Figure" in the manuscript.
8. Please improve the English writing. You are clearly presenting an analysis of data between 2010 and 2020, so please use past tense in the manuscript accordingly.
Comments on the Quality of English LanguageEnglish language needs improvement to effectively present your data and interpretation to the readers.
Author Response
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Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsIn the revised manuscript, the authors have addressed the major concerns I had, and I would therefore recommend acceptance for publication.
There are a couple of minor things to correct.
1. Please go over the manuscript again to make sure that past tense was used accordingly such as line 235, 237.
2. The citation format in the manuscript should follow the requirement of the journal, for example, instead of using [1][2][3], use [1,2,3].
3. Please add a period symbol at the end of your table and figure titles.
Comments on the Quality of English LanguageAcceptable.
Author Response
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