Improving Electricity Generation during the Product Reaction Loop and the Use of Exhaust Gas for Co-Product Production Using Polyethylene Waste and Flue Gas or Wood

Round 1

Reviewer 1 Report

Comments:

More energy-efficient industries could reduce the problems of pollution, global warming, energy security, and fossil fuel depletion, including processing waste into raw materials and more efficient energy cogeneration. Waste can be converted into useful products and energy, while efficient electricity cogeneration can be carried out using high-pressure reaction looping and exhaust gases.

This research proposed an upgraded electricity cogeneration technique, which was carried out in two steps and based on the productive use of otherwise useless polyethylene waste, flue gas, wood, and electricity cogeneration. The approach is illustrated using an existing methanol production process, using sustainable raw materials, including electricity cogeneration during the reaction loop and exhaust gas, generating a possible increase in annual profit of 7.28 MEUR/a.

From my side, the work is interesting, but it should be carefully revised before reconsideration. I have listed some basic questions, and hope these comments will help the authors to improve the manuscript.

1)      The abstract is too wordy. The research background and significance of this work were too vague, the logic was not close enough, and the exact novelty and contribution of this article were not pointed out.

2)      Please reorganize the introduction. The Research progress, existing problems, and solutions you adopted, etc. should be mentioned in the introduction.

3)      Please polish the English writing. There are too many single sentences. Too much “XXX can XXX.”

4)      “using the Aspen Plus simulator. “ please mention the Aspen Plus version and take care of the copyright of the Aspen Plus software(This is Commercial software).

5)      Introduction>. You should classify these references, rather than list them one by one, and put forward the work background, then the research progress, the existing problems, and then the necessity of the research, your innovation, and the expected results. If you have no experience, you can refer to several articles. [1–5]

[1]       E. Karasavvas, K.D. Panopoulos, S. Papadopoulou, S. Voutetakis, Energy and exergy analysis of the integration of concentrated solar power with calcium looping for power production and thermochemical energy storage, Renew. Energy. 154 (2020) 743–753.

[2]       X. Shi, H. Xiao, H. Azarabadi, J. Song, X. Wu, X. Chen, K.S. Lackner, Sorbents for the Direct Capture of CO2 from Ambient Air, Angew. Chem. Int. Ed. 59 (2020) 6984–7006.

[3]       M.T. Dunstan, F. Donat, A.H. Bork, C.P. Grey, C.R. Müller, CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances, Chem. Rev. 121 (2021) 12681–12745.

[4]       Y. Xu, B. Lu, C. Luo, F. Wu, X. Li, L. Zhang, Na2CO3 promoted CaO-based heat carrier for thermochemical energy storage in concentrated solar power plants, Chem. Eng. J. 435 (2022) 134852.

[5]       S. Yusuf, L. Neal, V. Haribal, M. Baldwin, H.H. Lamb, F. Li, Manganese silicate based redox catalysts for greener ethylene production via chemical looping – oxidative dehydrogenation of ethane, Appl. Catal. B Environ. 232 (2018) 77–85. 

6)      The Figures in the manuscript are too poor. Should be improved.

7)      Line 173, 176, 195, etc. The Eqs. (XX) should be numbered.

8)      Typesetting should be improved.

9)      Pleased double-check the rationality of the formula carefully, and the readability in the manuscript is poor.

10)    Line 352. “this way could reduce CO2 emissions by 1.9 106 kmol/a.” how did you get this comment?

11)    Line 358. “in the first step,” The first letter should be capitalized.

12)    The conclusion is too long and not concise.

13)    The number of references is too small. Should be added more (at least 45+), this is a research paper rather than an experimental report, right?

14)    The acknowledgment is missing.

Author Response

Dear!

Thanks for your reviews!

Anita Kovac Kralj

 

Reviewer 1

Comments and Suggestions for Authors

From my side, the work is interesting, but it should be carefully revised before reconsideration. I have listed some basic questions, and hope these comments will help the authors to improve the manuscript.

• The abstract is too wordy. The research background and significance of this work were too vague, the logic was not close enough, and the exact novelty and contribution of this article were not pointed out.

Answer:

The second sentence was deleted:

Waste can be converted into useful products and energy, while efficient electricity cogeneration can be carried out using high-pressure reaction looping and exhaust gases.

The abstract was improved with novelties:

This research project considers the novelties of the upgraded electricity cogeneration technique, including one open gas turbine during the high-pressure product reaction loop and a second turbine during the exhaust gas for co-product production with only one compressor. The upgraded electricity cogeneration is carried out in two steps and based on the productive use of otherwise useless polyethylene waste, flue gas and wood:

 

• Please reorganize the introduction. The Research progress, existing problems, and solutions you adopted, etc. should be mentioned in the introduction.

Answer: It was corrected.

 

• Please polish the English writing. There are too many single sentences. Too much “XXX can XXX.”

 Answer: It was corrected by lector.

 

• “using the Aspen Plus simulator. “ please mention the Aspen Plus version and take care of the copyright of the Aspen Plus software(This is Commercial software).

Answer: It was replaced with: Aspen Plus^®

 

5)      Introduction>. You should classify these references, rather than list them one by one, and put forward the work background, then the research progress, the existing problems, and then the necessity of the research, your innovation, and the expected results. If you have no experience, you can refer to several articles. [1–5]

[1]       E. Karasavvas, K.D. Panopoulos, S. Papadopoulou, S. Voutetakis, Energy and exergy analysis of the integration of concentrated solar power with calcium looping for power production and thermochemical energy storage, Renew. Energy. 154 (2020) 743–753.

[2]       X. Shi, H. Xiao, H. Azarabadi, J. Song, X. Wu, X. Chen, K.S. Lackner, Sorbents for the Direct Capture of CO2 from Ambient Air, Angew. Chem. Int. Ed. 59 (2020) 6984–7006.

[3]       M.T. Dunstan, F. Donat, A.H. Bork, C.P. Grey, C.R. Müller, CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances, Chem. Rev. 121 (2021) 12681–12745.

[4]       Y. Xu, B. Lu, C. Luo, F. Wu, X. Li, L. Zhang, Na2CO3 promoted CaO-based heat carrier for thermochemical energy storage in concentrated solar power plants, Chem. Eng. J. 435 (2022) 134852.

[5]       S. Yusuf, L. Neal, V. Haribal, M. Baldwin, H.H. Lamb, F. Li, Manganese silicate based redox catalysts for greener ethylene production via chemical looping – oxidative dehydrogenation of ethane, Appl. Catal. B Environ. 232 (2018) 77–85. 

Answer: The introduction was added with additional sentences and refererences: 

1. Introduction

Various waste-to-energy (WTE) conversion technologies can generate energy, more sustainable production, and useful co-products.

The energy efficiency was improved with the combined of heat and mechanical power.  Kalitventzeff and co-authors [1] described this application within an ammonia production plant, revisiting the major rules of energy integration from the perspective of overall energy efficiency, including the combined production of heat and mechanical power for an existing process.

The co-product, as CO₂ was used as the energy source in different industries. Sabtini et al. [2] investigated closed CO₂ cycles for existing nuclear power stations, and their study showed that s-CO₂ was suitable for this application. Pham et al. [3] analysed the performance of s-CO₂ used in the application of small modular reactors, and showed that the thermal efficiency of s-CO₂ could be increased by modifying the cycle configurations. Kim et al. [4] compared s-CO₂ with different configurations, which were applied as the bottoming cycle of a landfill gas fired gas turbine. Amini and others [5] focused on waste heat recovery for exhaust gases (at 150°C) from combined cycle power plants. Their results indicated that the t-CO₂ could produce more power and enhance the total efficiency of the power plant.

 Liquefied natural gas was utilised in plants. Shi et al. [6] proposed a system in which a liquefied natural gas cold stream was used for in-house compressor inlet air cooling, and reported an overall enhancement of 3% in electricity production. Wang and others [7] followed a formal mathematical programming approach to identify performance improvement opportunities in a liquefied natural gas plant.

The waste was used as the raw materials in different plants. Zhao et al. [8] studied the gasification of a local municipal solid waste (MSW) mixture. Chen and others [9] proposed the use of zeotropic mixtures with refrigerants as working fluids in the Organic Rankine Cycle process for waste heat recovery. Lee et al. [10] studied compressed natural gas and ethanol production from MSW. Pyrolysis processes convert waste into bio-char, bio-oil, and gases [11], and this bio-oil can be hydro processed further to produce gasoline and diesel blend stocks [12]. Cucchiella et al. [13] presented a strategy analysis of the amount of waste required to incinerate with energy recovery, considering different approaches based on unsorted waste, landfilled waste and separated collection rate, respectively. Beyene et al. [14] reviewed the recent and emerging waste to energy (WtE) technologies which advance toward using MSW to produce renewable energy. Lee et al. [15] studied compressed natural gas and ethanol production from MSW.

            The heat integration and use of multiple feeds recovered the energy into various industries. Fujii and co-workers [16] presented a combined system which would use biogas to heat steam recovered from an incineration boiler with separate superheating equipment. Hwang [17] analysed the performance of an integrated vapour compression refrigeration system with a micro turbine and vapour absorption chiller driven by waste heat from the microturbine. Gogoi and Talukdar [18] performed a detailed thermodynamic analysis of a combined reheat regenerative steam based on the power cycle and H₂O-LiBr vapour absorption refrigeration system from a first law point of view, and also an exergy-based parametric analysis of the same system. Ge et al. [19] evaluated the performance, with simulation and experiment, of a gas turbine power plant integrated with an absorption system for a supermarket. Soltanieh et al. [20] studied the implementation of large-scale polygeneration plants which use multiple feeds (such as coal and natural gas), and produce multiple products (such as power, liquid fuels and chemicals).

The modification and upgrade of turbines improved the turbines` working. Musacchio and co-workers [21] presented the single components of the gas turbine,  decarbonising materials` sourcing and machining in the gas turbine sector, through a cost-carbon footprint nexus analysis. Liu et al. [22] studied the performance comparison of three configurations of an aviation fuel cell gas turbine hybrid power generation system. Cha and researchers [23] designed a gas turbine-carbon dioxide combined cycle power plant (GT-CO₂ CCPP) with a gas turbine inlet air cooling and heat recovering system when using liquefied natural gas cold energy. 

Concentrated solar power (CSP) can be converted into electricity by using solar energy and calcium looping [24]. Thermal energy storage (TES), phase change materials (PCM), and thermochemical energy storage (TCES) systems constitute the most interesting and applicable energy storage technologies for CSP [[25], [26]]. One of the most promising chemical systems for TCES in large scale production is the CaO/CaCO₃ performing the calcium looping (CaL) process [[27], [28]], including different sorbents for direct air capture of carbon dioxide (CO₂), which takes place in the calcination-carbonation reaction [29], [30]].

This paper presents electricity generation using one and/or two open gas turbines by using the upgraded electricity cogeneration technique.

 

 

• The Figures in the manuscript are too poor. Should be improved.

Answer: It was improved; especially arrows contacts.

• Line 173, 176, 195, etc. The Eqs. (XX) should be numbered.

Answer: It was numbered and added the”:”

Model A also included the installation of one gas turbine (Ca_TUR-1=0.1 MEUR/a) and heating of steam within the SH heat exchanger (Ca_SH=0.4 MEUR/a). The profit of Model A (Prof_A,PP) was 7.18 MEUR/a, including natural gas being replaced with polyethylene waste and flue gas (Eq. 14):

Prof_A,PP = S_raw,_PP + In_CH3OH,A + In_el-TUR-1- Ca_H2- Cd_TUR-1- Ca_TUR-1- Ca_SH                         

              =  4.3 + 4 + 1.134 - 1.52 - 0.234 - 0.1- 0.4 = 7.18 MEUR/a                               (14)

 

 

• Typesetting should be improved.

Answer: It was corrected by lector.

• Pleased double-check the rationality of the formula carefully, and the readability in the manuscript is poor.

       Answer: It was corrected

10)    Line 352. “this way could reduce CO2 emissions by 1.9 106 kmol/a.” how did you get this comment?

        Answer: It was added the sentence:

     The use of flue gas in this way could reduce CO₂ emissions by 1.9 10⁶ kmol/a, because flue gas is not released into the atmosphere. 

 

11)    Line 358. “in the first step,” The first letter should be capitalized.

Answer: It was corrected.

12)    The conclusion is too long and not concise.

Answer: It was corrected. The sentences were deleted:

The maximum available electricity cogeneration can be previously determined from the product’s and co-products’ thermodynamics. The comparison between the existing energy units’ characteristic capacity and after the change in raw material for Models A and B confirmed the usage of the existing units was a good idea. 

 

 

13)    The number of references is too small. Should be added more (at least 45+), this is a research paper rather than an experimental report, right?

Answer: Some were added:

[13] F. Cucchiella, I. D’Adamo, M. Gastaldi, Sustainable waste management: waste to energy plant as an alternative to landfill, Energy Convers Management, 13, (2017), pp. 18-31.

[14] H.D. Beyene, A.A. Werkneh, T.G. Ambaye, Current updates on waste to energy (WtE) technologies: a review, Renewable Energy Focus, 24 (2018), pp. 1-11.

[15] U. Lee, J. Han, M. Wang, Well-to-Wheels Analysis of Compressed Natural Gas and Ethanol from Municipal Solid Waste, ANL/ESD-16/20, Argonne National Laboratory, Argonne (2016).

[24] S.E.B. Edwards, V. Materić, Calcium looping in solar power generation plants, Sol. Energy, 86 (2012), pp. 2494-2503.

 

[25] E. Karasavvas, K.D. Panopoulos, S. Papadopoulou, S. Voutetakis, Energy and exergy analysis of the integration of concentrated solar power with calcium looping for power production and thermochemical energy storage, Renew. Energy. 154 (2020) 743–753.

 

[26] Y. Xu, B. Lu, C. Luo, F. Wu, X. Li, L. Zhang, Na2CO3 promoted CaO-based heat carrier for thermochemical energy storage in concentrated solar power plants, Chem. Eng. J. 435 (2022) 134852.

 

[27] R.  Chacartegui,  A. Alovisio,  C.  Ortiz, J. M.  Valverde,  V. Verda, J. A. Becerra, Thermochemical energy storage of concentrated solar power by integration of the calcium looping process and a CO₂ power cycle,Appl. Energy, 173 (2016), pp. 589-605.

 

[28] F. Miccio, F. Doghieri, E. Landi, Insights into high temperature sorbents for carbon dioxide,Chem. Eng. Trans., 43 (2015), pp. 901-906.

[29] X. Shi, H. Xiao, H. Azarabadi, J. Song, X. Wu, X. Chen, K.S. Lackner, Sorbents for the Direct Capture of CO2 from Ambient Air, Angew. Chem. Int. Ed. 59 (2020), pp. 6984–7006.

[30] M.T. Dunstan, F. Donat, A.H. Bork, C.P. Grey, C.R. Müller, CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances, Chem. Rev. 121 (2021) 12681–12745.

 

 

14)    The acknowledgment is missing.

Answer: It was included:

      The authors thankfully acknowledge the financial assistance obtained from Ministry of Education, Science and Technology, Slovenia.

Author Response File: Author Response.docx

Reviewer 2 Report

Various waste to energy conversion technologies can generate energy, more sustainable production, and useful co-products. The current manuscript is trying to investigate electricity cogeneration during the reaction loop and exhaust gas using sustainable raw materials and to provide some options for the methanol production process. However, this research is lacking of scientific and reliable experimental design. Some data in the figures did not show replicates and no tables. It is suggested that a rejection could be reached. Besides, the abstract and introduction need to be modified carefully due to the lack of no innovative and systematic.

Author Response

 

Reviwer 2

Dear!

Thanks for your reviews!

Anita Kovac Kralj

Comments and Suggestions for Authors

Various waste to energy conversion technologies can generate energy, more sustainable production, and useful co-products. The current manuscript is trying to investigate electricity cogeneration during the reaction loop and exhaust gas using sustainable raw materials and to provide some options for the methanol production process. However, this research is lacking of scientific and reliable experimental design. Some data in the figures did not show replicates and no tables. It is suggested that a rejection could be reached. Besides, the abstract and introduction need to be modified carefully due to the lack of no innovative and systematic.

Answer:

This paper was corrected. It was added the novelties in abstract. The introduction was enlarged. The technique, problem and conclusions were improved.

Author Response File: Author Response.docx

Reviewer 3 Report

Reducing pollution and reducing global warming is a very important issue. The publication describes the concept of converting waste into energy, which is a very interesting and important aspect of energy security and at the same time affects the reduction of pollution. 

The concept presented, more precisely the result of simulation of model B allows an additional profit of 7.28 MEUR/a with additional methanol production. This is an impressive result, which is worth developing further. 

The weaker element is the introduction. It lacks a clear link between the cited studies and the concept described in the publication. It is clear that there is ongoing work related to waste-to-energy conversion, more sustainable production or by-product management. It would be worthwhile to refer in the introduction to studies and examples of electricity generation during a product reaction loop or the use of flue gas to produce a by-product. E.g., why is Sabtini et al. cited. [2] line 36-37 and Wang et al [7] line 51-52? How do the issues raised there affect the problem being analyzed?  

Author Response

Dear!

Thanks for your reviews!

Anita Kovac Kralj

Reviwer 3

Comments and Suggestions for Authors

 

Reducing pollution and reducing global warming is a very important issue. The publication describes the concept of converting waste into energy, which is a very interesting and important aspect of energy security and at the same time affects the reduction of pollution. 

The concept presented, more precisely the result of simulation of model B allows an additional profit of 7.28 MEUR/a with additional methanol production. This is an impressive result, which is worth developing further. 

The weaker element is the introduction. It lacks a clear link between the cited studies and the concept described in the publication. It is clear that there is ongoing work related to waste-to-energy conversion, more sustainable production or by-product management. It would be worthwhile to refer in the introduction to studies and examples of electricity generation during a product reaction loop or the use of flue gas to produce a by-product. E.g., why is Sabtini et al. cited. [2] line 36-37 and Wang et al [7] line 51-52? How do the issues raised there affect the problem being analyzed?  

Answer: The interdiction was improved.

Author Response File: Author Response.docx

Reviewer 4 Report

 I am a bit dismayed at the used of English in this paper, it is important that the author checks and revises her manuscript carefully, preferably with the assistance of a native English speaker, to ensure the work is reported and discussed clearly.

Author Response

 

 

 

Reviwer 4

Comments and Suggestions for Authors

Dear!

Thanks for your reviews!

Anita Kovac Kralj

 I am a bit dismayed at the used of English in this paper, it is important that the author checks and revises her manuscript carefully, preferably with the assistance of a native English speaker, to ensure the work is reported and discussed clearly.

Answer: This paper was review by lector.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have revised the manuscript according to the commnets. Henece, I think it can be considered.

But, the Superscript and subscript of the works should be double-checked.

Author Response

Dear!

Thanks for your review.

Thanks

Anita Kovac Kralj

Reviewer 1

 

Comments and Suggestions for Authors

The authors have revised the manuscript according to the commnets. Henece, I think it can be considered.

But, the Superscript and subscript of the works should be double-checked.

Answer:

Thanks, it was corrected.

FCp_TUR,com; (F_CH3OH,ex)

Thanks.

Author Response File: Author Response.docx

Reviewer 2 Report

This article "Improving electricity generation during the product reaction loop and the use of exhaust gas for co-product production using polyethylene waste and flue gas or wood” was revised and has a novelty and I recommend it for consideration of the following comments.

Title: It is perfect.

Abstract:

·       The current gap of this research should be mentioned.

·       Keywords: waste should be changed into waste recovery.

Introduction:

·      Please provide the detailed introduction and summary about waste to energy using pyrolysis technology, such as biomass waste to bioenergy, biofuels and so on. It is suggest that the recent references could be refer to: (a) Journal of Cleaner Production, 2022, 355, 131768; (b) Biochemical Engineering Journal, 2022, 179, 108330.

·       Materials:

·                   Statistical analysis must be mentioned.

  “Results:

·       Figure 3, and 4: Please consider the statistical analysis comparing so that the alphabetical statistical letters for the means should all be modified.

By the way, there is no tables in this manuscript which the authors should be added for a clearly comparison and demonstration.

Discussion:

Discussion text must grammar improve and in some cases it is very weak and maybe there is no discussion at all.

Conclusions:

Conclusion is perfect.

References: It is OK.

The article has a little flaws in express and concept of English, it is suggested to be revised in a scientific and native way.

Author Response

Dear!

Thanks for your review.

Thanks

Anita Kovac Kralj

 

Reviewer 2

Comments and Suggestions for Authors

This article "Improving electricity generation during the product reaction loop and the use of exhaust gas for co-product production using polyethylene waste and flue gas or wood” was revised and has a novelty and I recommend it for consideration of the following comments.

Title: It is perfect.

Abstract:

• The current gap of this research should be mentioned.

Answer: it was added: This research of electricity generation based on the processes, which including pressure drop during the product reaction loop.

 

• Keywords:waste should be changed into waste recovery.

Answer: It was corrected.

Keywords: waste recovery

Introduction:

• Please provide the detailed introduction and summary about waste to energy using pyrolysis technology, such as biomass waste to bioenergy, biofuels and so on. It is suggest that the recent references could be refer to: (a) Journal of Cleaner Production, 2022, 355, 131768; (b) Biochemical Engineering Journal, 2022, 179, 108330.

Answer: It was added:

The biomass waste was used for the bioenergy and biofuels using pyrolysis technology. Li and co-researchers [16] investigated a strategy of adjusting the nutrient composition of the feeding wastewater for microalgae cultivation and biofuel production. Huang et al. [17] presented a new workflow of biofuel generation from microalgae biomass through lipid extraction and pyrolysis of defatted microalgae residues.

[16] Gang Li, Ruichen Hu, Nan Wang, Tenglun Yang, Fuzhuo Xu, Jiale Li, Jiahui Wu, Zhigang Huang, Minmin Pan, Tao Lyu, Cultivation of microalgae in adjusted wastewater to enhance biofuel production and reduce environmental impact: Pyrolysis performances and life cycle assessment, Journal of Cleaner Production, 355, (2022), 131768.

 

[17] Zhigang Huang, Jiang Zhang, Minmin Pan, Yuhang Hao, Ruichen Hu, Wenbo Xia, Gang Li, Tao Lyu,Valorisation of microalgae residues after lipid extraction: Pyrolysis characteristics for biofuel production, Biochemical Engineering Journal, 179, (2022), 108330.

• Materials:
•  Statistical analysis must be mentioned.

 

Answer: It was added (pp.10): Table1:

Table 1: The comparison between Models A and B for the crude methanol production from polyethylene waste and flue gas.

	Model A	Model B	Difference,%
Electricity cogeneration, MW	2.52	2.52 +1.4=3.92	55
Additional methanol production, kmol/h	170	155	-9
Separated hydrogen, kmol/h	1560	1560	/
Profit, MEUR/a	7.18	7.28	1.4

 

  “Results:

• Figure 3, and 4: Please consider the statistical analysis comparing so that the alphabetical statistical letters for the means should all be modified.

Answer: It was added (pp.8):

The electricity cogeneration within the gas turbine (ϕ_TUR-1) was presented 20% of the available energy (ϕ_R,out; Fig.3).

The electricity cogenerations within the gas turbines TUR-1 (ϕ_TUR-1) and TUR-2 (ϕ_TUR-2) were presented 20% and 11% of the available energy (ϕ_R,out; Fig.4).

Answer: The alphabets of Fig. 3 and 4 were added with ɸ.

 

By the way, there is no tables in this manuscript which the authors should be added for a clearly comparison and demonstration.

Answer: It was added Table 1.

Discussion:

Discussion text must grammar improve and in some cases it is very weak and maybe there is no discussion at all.

Answer: It was improved (pp. 9):

The comparisons between Models A and B for the crude methanol production from polyethylene waste and flue gas were presented in Table 1. Model B was operated with 55% higher electricity cogeneration, with 9% lower methanol production and with1.4% higher profit.

 

 

Conclusions:

Conclusion is perfect.

References: It is OK.

The article has a little flaws in express and concept of English, it is suggested to be revised in a scientific and native way.

Anwser:I am sorry, but it was reviewed by native and scientific lector.

 

Author Response File: Author Response.docx