Discussion on the Feasibility of the Integration of Wind Power and Coal Chemical Industries for Hydrogen Production

Round 1

Reviewer 1 Report

From my point of view, this manuscript could be accepted to Sustainability. The content is succinctly described and contextualized with respect to previous and present theoretical background and empirical research on the topic (integration of wind power and coal chemical industry for hydrogen production). The research design, questions, hypotheses and methods are clearly stated. The arguments and discussion of findings are coherent, balanced and compelling. The results are clearly presented.  The conclusions are thoroughly supported by the results presented in the manuscript. English language and style are fine. The manuscript is well illustrated and interesting to read.

Author Response

Sustainability-1407266

Re: “Discussion of the feasibility of the integration of wind power and coal chemical industry for hydrogen production”

 

Respond to Reviewer comments:

Comment

1. From my point of view, this manuscript could be accepted to Sustainability. The content is succinctly described and contextualized with respect to previous and present theoretical background and empirical research on the topic (integration of wind power and coal chemical industry for hydrogen production). The research design, questions, hypotheses and methods are clearly stated. The arguments and discussion of findings are coherent, balanced and compelling. The results are clearly presented.  The conclusions are thoroughly supported by the results presented in the manuscript. English language and style are fine. The manuscript is well illustrated and interesting to read.

Response

Thank you. I have modified the language according to your requirements, and marked the modified content in red in the paper. Thanks for the expert's valuable advice. I sincerely hope that this paper can be published in Sustainability.

Reviewer 2 Report

The manuscript reports on the feasibility of the integration of wind power and
coal chemical industry for hydrogen production. It is an interesting subject in the area of integrating clean power and fossil energy to reduce environmental impact. However, English needs improvement throughout the text. Also, some parts need to be addressed as below:

 

1)Some statements in the text are too long and should be divided to smaller sentences for better understanding.

2)Abstract: This statement is too long. Please spit it: ‘Considering the environmental and economic benefits of wind–coal coupling, a system is established to plan the total cycle-revenue to maximize the net present value goal programming model, realize coal clean and efficient utilization, and overcome challenges for new energy development.’

3)The content of the Abstract does not reflect the importance of hydrogen production included in the title? Please modify and improve the Abstract content.

4)L32-33: This statement is not clear: ‘Although the conversion of coal into natural gas achieves clean utilization of coal, the effect is insignificant.’

5)L62: Please include the names of the authors before numbers of the references.

6)L63: Exergy should be replaced by energy.

7)Section 2.1: Please use a more appropriate title for this instead of subsection.

8)Figure 1: Please put more details for chemical unit as of products and byproducts by names.

9)Each equation should be numbered separately.

10)Each parameter in each equation needs to be defined in the relevant text.

11)Which software was used for programming and analysis of the models? Not indicated?

12)L274-278: This sentence is not complete: ‘Analyze the economy of the coupling system under different capacity reliability scenarios (the pro- portion of the capacity of conventional units that can be replaced by wind turbine units to the installed wind power capacity under the premise of equal reliability, also known as trusted capacity).’

13)The title of figure 5 needs more clarification/explanation: ‘Figure 5. Typical daily curve of wind power and methanol production’

14)Please double check the units in Table 4.

 

Author Response

Sustainability-1407266

Re: “Discussion of the feasibility of the integration of wind power and coal chemical industry for hydrogen production”

 

Respond to Reviewer comments:

Comment

1. Some statements in the text are too long and should be divided to smaller sentences for better understanding.

Response

Thank you for pointing this. I have modified the language according to your requirements, and marked the modified content in red in the paper.

 

Comment

2. 2. Abstract: This statement is too long. Please spit it: ‘Considering the environmental and economic benefits of wind–coal coupling, a system is established to plan the total cycle-revenue to maximize the net present value goal programming model, realize coal clean and efficient utilization, and overcome challenges for new energy development.’

Response

Thank you. The relevant content has been modified according to your opinions and condensed into: ‘A system is established to plan the total cycle-revenue to maximize the net present value goal programming model and overcome challenges for new energy development.’

 

Comment

3. 3. The content of the Abstract does not reflect the importance of hydrogen production included in the title? Please modify and improve the Abstract content.

Response

Thanks a lot. The abstract has been modified and supplemented according to your suggestions, and the importance of wind power hydrogen production has been added. For example:‘Wind power hydrogen production generates O₂ and H₂, which are respectively used for methanol preparation and electricity production in coal chemical system.’

 

Comment

4. 4. L32-33: This statement is not clear: ‘Although the conversion of coal into natural gas achieves clean utilization of coal, the effect is insignificant.’

Response

Thank you very much. The author has supplemented and expanded the content according to the opinions of experts, and the modifications are as follows: ‘Although the conversion of coal into natural gas achieves clean utilization of coal, it greatly reduces pollutant emissions and is beneficial to improve the utilization efficiency of coal. However, we should also pay attention to the high carbon dioxide emission from coal to natural gas.’

 

Comment

5. 5. L62: Please include the names of the authors before numbers of the references.

Response

Thank you. I comprehensively checked and revised the labeling of the paper according to the expert opinions. Thank you for pointing this. It is has been modified in the revised manuscript. For example: Such as Li et al. (2017)[8], Zhuang et al. (2018)[9] and Firmansyah et al. (2018)[10] have found that different from traditional multi-energy coupling systems, new coal systems are coupled with the chemical industry and involve more energy forms, energy conversion processes, transmission means, and absorption pathways.

 

Comment

6. 6. L63: Exergy should be replaced by energy.

Response

Thank you. We are sorry for that. It has been modified in the revised manuscript. Thank you for pointing this.

 

Comment

7. 7. Section 2.1: Please use a more appropriate title for this instead of subsection.

Response

Thank you very much. The ‘2.1. Subsection’ has been replaced by ‘2.1. Basic framework’ in the revised manuscript. This section mainly describes the basic architecture of the Wind-coal coupled energy system, WCCES.

 

Comment

8. 8. Figure 1: Please put more details for chemical unit as of products and byproducts by names.

Response

Thank you. The main purpose of Figure 1 is to explain the main products of wind power hydrogen production are hydrogen and oxygen. They are used in the chemical production process to get more products, but they are not specific. The specific working mode and process are introduced in detail through the case analysis in Part 5.

 

Comment

9. 9. Each equation should be numbered separately.

Response

Thank you. We are sorry for that. It has been modified in the revised manuscript. Thank you for pointing this.

 

Comment

10. 10. Each parameter in each equation needs to be defined in the relevant text.

Response

Thank you. We are sorry for that. It has been modified in the revised manuscript. Thank you for pointing this. 

 

Comment

11. 11. Which software was used for programming and analysis of the models? Not indicated?

Response

Thank you for pointing this. We are sorry for that. It is an oversight. We built the simulation model of hydrogen producing system in pluripotent coupling system on the basis of MATLAB/Simulink , and the Genetic Algorithm (GA) is used to solve the model. The theoretical and technical parameters of each component of the wind power - hydrogen energy storage and coal chemical multi-energy coupling system are obtained. It has been modified in the revised manuscript. Thank you.

References

Yuan, T.J.; Hu, K.L.; Guan, Y.H; et al. Modeling on hydrogen producing progress in EMR based wind power-hydrogen energy storage and coal chemical pluripotent coupling system. High Voltage Engineering. 2015, 41(7), 2156-2164.

Yuan, T.J.; Duan, Q.X.; Qin, Y.H; et al. Energy wide-area coordination control architecture of wind power-hydrogen energy storage and coal chemical multi-functional coupling system. Adv. Eng. Sci. 2016, 42(9), 2748-2755.

Yuan, T.J.; Li, G.J.; Zhang, Z.Q; et al. Optimal modeling on equipment investment planning of wind power-hydrogen energy storage and coal chemical pluripotent coupling system. Rock Soil Mech. 2016, 31(14), 21-30.

 

 

Comment

12. 12. L274-278: This sentence is not complete: ‘Analyze the economy of the coupling system under different capacity reliability scenarios (the pro- portion of the capacity of conventional units that can be replaced by wind turbine units to the installed wind power capacity under the premise of equal reliability, also known as trusted capacity).’

Response

Thank you so much. The description of the sentence had been corrected in the manuscript. This sentence is complete noe: ‘It can be used to analyze the economic distribution of the coupling system under different capacity reliability of wind farms in Fig. 5 . Among them, the capacity credit of wind power is defined as the ratio of capacity which is equivalent as conventional generation to serve the load as a same reliability level. It is an important indicator measuring its contribution to the power system adequacy.’

References

Zhang, N.; Kang, C.Q.; Xiao, J.Y; et al. Review and Prospect of Wind Power Capacity Credit. Proceedings of the CSEE. 2015, 35(1), 82-94.

 

Comment

13. 13. The title of figure 5 needs more clarification/explanation: ‘Figure 5. Typical daily curve of wind power and methanol production’

Response

Thank you very much. The title of Figure 5 has been changed in the revised manuscript: Daily active power delivered to the grid and methanol production distribution curve. Among them, it needs to be explained that wind power consumption refers to the active power transmitted by wind field to the power grid.

 

Comment

14. 14. Please double check the units in Table 4.

Response

Thank you very much. We are sorry for that. It is a mistake. The ‘kg’ has been replaced by ‘L’ in the revised manuscript.

Reviewer 3 Report

1. Please provide references for prices.
2. Would be nice to have a better literature review on what has been published/built in combination of coal industry with other  renewable resources, or similar projects
3. Would be nice to discuss potential hazards, risks, difficulties comprising from this combination 

Author Response

Sustainability-1407266

Re: “Discussion of the feasibility of the integration of wind power and coal chemical industry for hydrogen production”

 

Respond to Reviewer comments:

Comment

1. Please provide references for prices.

Response

Thanks for reviewer’s kind remind. Tables 1, 2, and 3 show the energy price list, the related technical parameters of the traditional coal-to-methanol system and the coupling system, and the simulation parameters of the coupling system, respectively. Tables 2 and 3 show that compared with the traditional coal-to-methanol system, for every ton of methanol produced, the WCCES consumes 0.6 tons of coal, reduces water consumption by 2 tons, reduces CO₂ emissions by 2.24 tons, and consumes electricity of 6.25 MWh.Table 4 shows the specific costs and benefits of the coupling system when the trusted capacities of the wind farm are 0.2 and 0.36. The results show that with an increase in the number of the trusted capacities of the wind farm, the rated power of the planned electrolytic cell and the capacity of the hydrogen storage tank decrease, and the system income increases. The analysis shows that the capacity reliability of wind farms increases from 0.2 to 0.36, the typical daily total power generation of wind farms with the coupling system increases from 2400 to 4317 MWh, and the cost of purchasing power and producing hydrogen is saved by 309 million yuan in the planning period. In addition, there is no need to increase the rated operating power of the electrolytic cell and the capacity of the hydrogen storage tank to reduce the cost of electricity purchase and the investment cost of the system. Table 5 shows the credibility of wind farms under different coal-to-methanol schemes at 0.3, the price of methanol is 2,500 yuan per ton, and the coal-to-methanol system is 20 years old.

Comment

2. Would be nice to have a better literature review on what has been published/built in combination of coal industry with other renewable resources, or similar projects.

Response

Thanks a lot. We have added the introduction about the combination of coal industry with other renewable resources in the revised manuscript. proposed hydrogen energy coupled with coal chemical industry boosts the properties of coal raw materials to achieve carbon neutrality [9]. Therefore, an entry point for the development of hydrogen energy-coal-based energy industry is put forward, including establishment of integrated industrial development mode, activation of raw material properties of coal and realization of zero emission of CO2 (Wang, M.H et al., 2021; Wang, M.H et al., 2021; Yuan, T.J et al.,2016.)

References

Wang, M.H. System performance analysis and development suggestions of hydrogen energy coupling coal to olefin to boost coal raw material properties to achieve carbon neutralization. Mod Chem Ind 2021,(),1-8.

Wang, M.H. Research on strategic transformation paths for hydrogen energy-coal-based energy industry. Mod Chem Ind 2021, 41(07):1-4.

Yuan, T.J.; Li, G.J.; Zhang, Z.Q. et al. Energy wide-area coordination control architecture of wind power-hydrogen energy storage and coal chemical multi-functional coupling system [J]. Transactions of China Electrotechnical Society 2016, 31(14):21-30.

Comment

3. Would be nice to discuss potential hazards, risks, difficulties comprising from this combination.

Response

Thank you for pointing this. We are so sorry for not describing clearly about the challenges of WCCES. The operating efficiency of WCCES is one of the issues to be considered. Including the efficiency of water electrolysis, the efficiency of hydrogen storage and release, and the efficiency of hydrogen transportation and utilization. All or most of the electrical energy required by G-WHCES is provided by intermittent new energy sources, coupled with the fluctuation of electrical load and hydrogen load, it highlights the system supply and demand balance problem under the uncertainty of multi-time and space coupling. In addition, The innovation and development of highly adaptable wind turbines is also critical to WCCES hydrogen production technology which can be found in those studies (Peng et al., 2019; Shen et al., 2019; Yoshida et al.,2015; Valdés et al.)

And we have added the introduction about the challenge between the integration of wind power and coal chemical industry in the revised manuscript.

References

Peng S.; Yang S.; Yuan T, et al. Challenges and Prospects of Generalized Wind-Hydrogen-Coal Energy System[J]. Automation of Electric Power Systems 2019,43(24):6-12.

Shen X.W.; GUO Q.L.; XU Y.L.; et al. Robust planning method for regional integrated energy system considering multi-energy load uncertainties[J].Automation of Electric Power Systems 2019,43(7):34-45

Yoshida Y, Umemura A, Takahashi R, et al. Experimental study of hydrogen production system with stand-alone wind power generators[C]//IEEE Tenth International Conference on Ecological Vehicles and Renewable Energies, Monte Carlo, Monaco 2015:1-5.

Valdés R, Lucio J H, Rodríguez L R. Operational simulation of wind power plants for electrolytic hydrogen production connected to a distributed electricity generation grid[J]. Renewable Energy 2013, 53(9):249-257.

Round 2

Reviewer 2 Report

The comments are addressed carefully and the manuscript is in acceptable form now.