Thermoeconomic Modeling as a Tool for Internalizing Carbon Credits into Multiproduct System Analysis

Round 1

Reviewer 1 Report

The Manuscript "Thermoeconomic Modeling as a Tool for Internalizing Carbon Credits into Multiproduct System Analysis" elaborates on how thermoeconomic modeling can be adapted to incorporate expenses or revenues associated with the carbon market and consequently allocate it to the final products, using a cogeneration system as an example. Furthermore, it underscores the applicability of this modeling approach to internalize other costs, such as those incurred for environmental control devices, licenses, and permits. Some exergy disaggregation models define a device  to represent the environment within diagrams, and this component plays a key role in incorporating environmental burdens. However, even models lacking an explicit environmental device can still internalize carbon credits and allocate them to the final products. By incorporating carbon credits into thermoeconomic modeling, it becomes possible to evaluate the financial and environmental implications of emissions, incentivize the reduction of GHG, and optimize the system's design and operation.

However I have some comments on this manuscript.

1. The introduction part needs to be explained in the context of the problem identification. For this, some recent studies should be added to magnify the problem statement.

2. The manuscript has some minor English mistakes. So a thorough English language review is required.

3. The thermoeconomic model has not been validated. This is a major concern. This should be validated so that the results should be more acceptable to the researchers.

After this revision, the manuscript needs to be considered again for the review and then publishing.

 

The Manuscript "Thermoeconomic Modeling as a Tool for Internalizing Carbon Credits into Multiproduct System Analysis" elaborates on how thermoeconomic modeling can be adapted to incorporate expenses or revenues associated with the carbon market and consequently allocate it to the final products, using a cogeneration system as an example. Furthermore, it underscores the applicability of this modeling approach to internalize other costs, such as those incurred for environmental control devices, licenses, and permits. Some exergy disaggregation models define a device  to represent the environment within diagrams, and this component plays a key role in incorporating environmental burdens. However, even models lacking an explicit environmental device can still internalize carbon credits and allocate them to the final products. By incorporating carbon credits into thermoeconomic modeling, it becomes possible to evaluate the financial and environmental implications of emissions, incentivize the reduction of GHG, and optimize the system's design and operation.

However I have some comments on this manuscript.

1. The introduction part needs to be explained in the context of the problem identification. For this, some recent studies should be added to magnify the problem statement.

2. The manuscript has some minor English mistakes. So a thorough English language review is required.

3. The thermoeconomic model has not been validated. This is a major concern. This should be validated so that the results should be more acceptable to the researchers.

After this revision, the manuscript needs to be considered again for the review and then publishing.

 

Author Response

Dear Reviewer,

 

We sincerely appreciate your thorough review of our manuscript and the invaluable feedback you've provided. Your insights have played a significant role in refining our work, and we are grateful for your constructive comments. We want to assure you that your input has been carefully considered and integrated into the manuscript to enhance its quality and contribution. Below is a summary of the responses to your inquiries regarding the text.

1. 
   The introduction part needs to be explained in the context of the problem identification. For this, some recent studies should be added to magnify the problem statement.
   
   

In response to your suggestion, we have expanded the introduction section to provide a clearer context for the problem identification. We have incorporated recent studies to enhance the problem statement. Specifically, references 10, 11, and 12 have been integrated into the text to underscore the significance of the challenges addressed in our study.

10. 
    Palacios-Bereche, M.C.; Palacios-Bereche, R.; Ensinas, A.V.; Gallego, A.G.; Modesto, M.; Nebra, S.A. Brazilian Sugar Cane Industry – A Survey on Future Improvements in the Process Energy Management. Energy 2022, 259, 124903, doi:10.1016/j.energy.2022.124903.
11. Man, Y.; Yan, Y.; Wang, X.; Ren, J.; Xiong, Q.; He, Z. Overestimated Carbon Emission of the Pulp and Paper Industry in China. Energy 2023, 273, 127279, doi:10.1016/j.energy.2023.127279.
12. Mishra, R.; Singh, R.K.; Gunasekaran, A. Adoption of Industry 4.0 Technologies for Decarbonisation in the Steel Industry: Self-Assessment Framework with Case Illustration. Ann Oper Res 2023, doi:10.1007/s10479-023-05440-0.

By integrating these recent studies, we aim to provide a more comprehensive backdrop for our research, emphasizing the relevance and magnitude of the issues at hand.

2. The manuscript has some minor English mistakes. So a thorough English language review is required.

Thank you for the feedback. We have already conducted a thorough revision of the manuscript to address the English language errors.

3. The thermoeconomic model has not been validated. This is a major concern. This should be validated so that the results should be more acceptable to the researchers.
   
   We appreciate your concern regarding the validation of the thermoeconomic model. Validating the model is indeed a crucial step in ensuring the credibility and robustness of the results. We have included the following text in the new submitted version and highlighted it in green.

The purpose of thermoeconomic modeling is to derive a system of cost equations that mathematically represents the cost formation process, i.e., the process of allocating external resources until the final cost of products is established.

Costs can be deemed satisfactory if they belong to a viable region of solutions for a given problem, and that the procedure for cost validation must be founded on the plant's behavior and thermodynamics, as irreversibility constitutes the cost-generating magnitude [7].

In all results, the ordered pair belongs to the straight solution, specific to the operating conditions of the plant. In addition, the models are consistent from a thermodynamic point of view according to the efficiencies and irreversibilities obtained.

 

Once again, we extend our gratitude for your valuable feedback, and we remain open to further suggestions or insights that could contribute to the continued improvement of our work.

 

Best regards,

Author Response File: Author Response.pdf

Reviewer 2 Report

Authors studied “Thermoeconomic Modeling as a Tool for Internalizing Carbon 2 Credits into Multiproduct System Analysis”. The following minor revisions need to be improved. 

1)      What is Thermoeconomic Modeling? How this modeling is beneficial?

2)      Avoid the citation like [10–14] and/or environmental [15–18] on page no. 3.

3)      Give the reference of all the equations like equations 1-3 on page no.  4

4)      Conclusion is too lengthy. Reduce its size just mentioning the main outcomes.

5)      What are the specific practical applications of this study? The authors must mention the same in Abstract and Introduction section of the manuscript.

6)      Revise the abstract to provide (i) the motivation behind this study (ii) the significance of the study, (iii) the aim of the study, (iv) the research methodology, (v) the major conclusion of the study, (vi) specific application of the study.

7)      What is the novelty of this research work? What are the differentiating factors that make this study unique?

8)      What are the limitations of the present study and what are the future recommendations. Please mention them in abstract.

9)      Results and discussion can be improved by mentioning the physical reasoning.

 

10)  Research gap can be clearly written. 

Author Response

Dear Reviewer 2,

We express our sincere gratitude for your meticulous review and insightful inquiries regarding our manuscript. Your thoughtful feedback has significantly contributed to the enhancement of our work, and we greatly appreciate your efforts in aiding the refinement of our research.

In response to your valuable suggestions:

• What is Thermoeconomic Modeling? How this modeling is beneficial?

The text below has been included and marked with green highlighting within the content to address the question.

The purpose of thermoeconomic modeling is to derive a system of cost equations that mathematically represents the cost formation process, i.e., the process of allocating external resources until the final cost of products is established.

Costs can be deemed satisfactory if they belong to a viable region of solutions for a given problem, and the procedure for cost validation must be founded on the plant's behavior and thermodynamics, as irreversibility constitutes the cost-generating magnitude [7].

In all results, the ordered pair belongs to the straight solution, specific to the operating conditions of the plant. In addition, the models are consistent from a thermodynamic point of view according to the efficiencies and irreversibilities obtained.

 

• Avoid the citation like [10–14] and/or environmental [15–18] on page no. 3.
  Your request has been addressed:

The citation style [10–14] and references related to environmental aspects [15–18] on page 3 have been revised accordingly, and these changes are indicated in the text with a light blue highlight.

Here is the added text: Consequently, a comparison becomes feasible between the exergetic/monetary/environmental costs of each product and the production cost of each individual product in separate systems, as shown in papers assessing: exergetic unit cost (in a regenerative gas turbine cogeneration system [13];  in a cogeneration system with gas turbine, intercooler, and supplementary firing [14]; and in a combined cycle [15]), monetary unit cost (in a gas turbine cogeneration system [16] and in a power generation system of a steel mill plant [17]), and emissions pollutant allocation (in gas and steam cogeneration systems [18], in a gas cogeneration system with supplementary firing [19], in a combined cycle [20], and in a dual product heat pump [21]).

• Give the reference of all the equations like equations 1-3 on page no.  4

Thank you for your query. We have meticulously reviewed and cross-checked all equation references in the manuscript. As of our analysis, all references appear to be coherent and correctly cited. We appreciate your thorough assessment of our work. However, if you identify any discrepancies or if there are specific points that require further clarification, we kindly request you provide more detailed guidance in your comments.

• Conclusion is too lengthy. Reduce its size just mentioning the main outcomes.

We've revised the conclusion as suggested, providing a concise summary of the main outcomes. Thank you for guiding us in improving the clarity and brevity of the conclusion section.

 

• What are the specific practical applications of this study? The authors must mention the same in Abstract and Introduction section of the manuscript.
• Revise the abstract to provide (i) the motivation behind this study (ii) the significance of the study, (iii) the aim of the study, (iv) the research methodology, (v) the major conclusion of the study, (vi) specific application of the study.

With the aim of addressing the reviewer's inquiries in questions 5 and 6, the abstract has been rephrased. Several key points are highlighted herein to provide clarity to the requested answers.

New Abstract: In the context of emissions, carbon dioxide constitutes a predominant portion of greenhouse gases (GHGs), leading to the use of the term "carbon" interchangeably with these gases in climate-related discussions. The carbon market has emerged as a pivotal mechanism for emission regulation, allowing industries that struggle to meet emission reduction targets to acquire credits from those who have successfully curbed their emissions below stipulated levels. Thermoeconomics serves as a critical tool for analyzing multiproduct systems prevalent in diverse sectors, including sugarcane and alcohol mills, paper and pulp industries, steel mills, and cogeneration plants. These systems necessitate frameworks for equitable cost/emission allocation. This study is motivated by the need to expand the scope of thermoeconomic modeling to encompass expenses or revenues linked with the carbon market. By utilizing a cogeneration system as a representative case, this research aims to demonstrate how such modeling can facilitate the allocation of carbon market costs to final products. Moreover, it underscores the adaptability of this approach for internalizing other pertinent costs, encompassing expenses associated with environmental control devices, licenses, and permits. Although certain exergy disaggregation models depict an environmental component within diagrams, which is integral for addressing environmental burdens, even models without explicit environmental devices can effectively internalize carbon credits and allocate them to final products. The integration of carbon credits within thermoeconomic modeling introduces the capability to assess both financial and environmental implications of emissions. This integration further incentivizes the reduction of GHGs and supports optimization endeavors concerning system design and operation. In summary, this study delves into the incorporation of carbon market dynamics into thermoeconomic modeling. It demonstrates the potential to allocate carbon-related costs, facilitates comprehensive cost analysis, encourages emission reduction, and provides a platform for enhancing system efficiency across industrial sectors.

(i) Motivation behind this study:

The motivation behind this study is rooted in the imperative to address emissions, particularly carbon dioxide, a dominant greenhouse gas. As carbon holds substantial significance in climate discussions due to its association with emissions, there is a need to explore its integration within thermoeconomic modeling. This exploration stems from the recognition that the carbon market plays a pivotal role in regulating emissions, providing an avenue for industries to manage their carbon-related costs and incentives.

(ii) Significance of the study:

The significance of this study lies in its potential to enhance the efficacy of thermoeconomic modeling by incorporating the dynamics of the carbon market. By doing so, it provides a framework to allocate carbon-related expenses or revenues to final products, thereby enabling a more comprehensive analysis of the true costs associated with emissions. This integration is essential for fostering environmentally conscious decision-making, incentivizing emission reduction, and achieving sustainable industrial practices.

(iii) Aim of the study:

The aim of this study is twofold. Firstly, it seeks to illustrate how thermoeconomic modeling can be adapted to encompass costs or revenues originating from the carbon market. It demonstrates the application of this approach using a cogeneration system as an exemplar. Secondly, the study endeavors to showcase the adaptability of this modeling methodology to encompass other costs beyond carbon-related ones, such as those tied to environmental control devices, licenses, and permits.

(iv) Research methodology:

The research methodology entails the utilization of thermoeconomic modeling techniques, particularly adapting them to incorporate carbon market-related expenses or revenues. A cogeneration system serves as the focal point for demonstrating this methodology. The study also highlights that even models without explicit environmental components can still allocate carbon credits to final products, underscoring the flexibility of the approach.

(v) Major conclusion of the study:

The major conclusion drawn from this study is that integrating carbon market dynamics within thermoeconomic modeling significantly enhances the assessment of financial and environmental implications associated with emissions. The study highlights the feasibility of allocating carbon-related costs to final products, providing a holistic understanding of emission-related expenses. This finding reinforces the potential to incentivize emission reduction and optimize system design and operation.

(vi) Specific application of the study:

The study's specific application revolves around industries employing multiproduct systems, such as sugarcane and alcohol mills, paper and pulp industries, steel mills, and cogeneration plants. These sectors commonly encounter challenges related to cost/emission allocation. By integrating carbon market factors into thermoeconomic modeling, the study offers these industries a means to accurately allocate carbon-related costs, assess the financial and environmental ramifications of emissions, and optimize their processes for both economic and ecological benefits.

• What is the novelty of this research work? What are the differentiating factors that make this study unique?

The novelty introduced in this study is to demonstrate how this internalization can be accomplished using thermoeconomic principles.

• What are the limitations of the present study and what are the future recommendations. Please mention them in abstract.

As per the journal's guidelines, the abstract has a maximum word limit. Since the abstract has already been rewritten to fulfill previous requests, the following text has been incorporated into the introduction.

Certainly, an aspect that could be incorporated into this study to facilitate the development and execution of future research is the inclusion of real-world data from industries, which will permit greater accuracy in the simulations. However, according to Lozano, one of the experts in this field, the beauty of a theory is usually shown in the simplicity of its forms and the generality of its message, but its power resides in its capacity to solve practical cases. Thus, it was used a simple Gas Turbine Cogeneration Plant for illustration of the method application. 

Future investigations should encompass various cogeneration systems. The range of industry types, each with its own operational complexities, provides a diverse array of insights into the adaptability and effectiveness of the modeling here proposed. Exploring different types of cogeneration systems can enhance the understanding of the pros and cons of incorporating carbon market factors into thermoeconomic analyses. These advancements hold the potential to enrich scholarly inquiry while driving practical industrial progress.

• Results and discussion can be improved by mentioning the physical reasoning.

Thank you for your input. We want to assure you that the text, especially in relation to the content preceding and encompassing Figure 6, already takes into consideration the aspect of providing physical reasoning. We tried to elucidate the underlying physical principles driving our results and discussions. However, considering your feedback, we have revisited the relevant sections once again to enhance the incorporation of physical reasoning. Despite our best efforts, if our revisions still fall short of the desired clarity in terms of physical reasoning, we kindly request you provide additional guidance regarding the specific areas or concepts that need further elaboration.

• Research gap can be clearly written.

The research gap has been described in the text as per the following passage and has also been highlighted in green:

Despite the practical relevance of this aspect, in the literature review, no studies were found that dealt with the incorporation and internalization of the monetary unit cost linked to the carbon market in the thermoeconomic evaluations of multi-product plants.

 

We deeply value your thorough assessment, which has undoubtedly enriched our work. Your contributions have strengthened the quality and impact of our research, and we remain receptive to further suggestions, improvements, or any clarifications that could continue to enhance our manuscript.

Warm regards,

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Accepted