Configurational Path of Decarbonisation Based on Coal Mine Methane (CMM): An Econometric Model for the Polish Mining Industry

In the abstract: what means “in the Polish steel industry” It should be “in the Polish mining industry”.

we changed, now is “mining”

In Introduction: lines: Using methods to capture them and use them in the energy production process is one of the scenarios for Polish mines [5]. The research part - the econometric model - was created on the basis of data obtained from Polish coal mines.

In my opinion, there should be a transition from one sentence to the next, perhaps state the aim of the research and the following sentence should be about the economic model.

You have to change the order of the sentences because the target (research aim) is before the Research Question (RQ)

We changed, now is:

Page 2

The introduction of methane emission restrictions according to EU regulations to standards of 5 tonnes of methane per 1,000 tonnes of coal mined in 2027 and 3 tonnes in 2031 is a big problem for the Polish mining industry. Currently, Polish mines emit more - on average 8 to 14 tonnes of methane per 1,000 tonnes of extracted coal. Although coking coal from Polish mines is classified as a European critical resource, methane emissions account for more than 70% of the reported carbon footprint. At the beginning of 2022, JSW SA was updating its strategy, including in the environmental area. Remedial work is moving towards working on better capture of methane from ventilation shafts and the development of alternative energy sources to balance the CO2e emitted. Thus, methane emissions are an important problem both economically and environmentally.

We think that the problem is not well known because researchers mainly concentrate their analysis on key renewable energy sources. However, we think the problem of methane is a very interesting and scientifically important research gap, especially in the deep decarbonisation. We should know what these economies like Poland, where mines are still key suppliers of energy sources, are up to. The extraction activities of mines are accompanied by released methane. On the one hand, there is a need to focus on methods for recovering methane and producing energy and heat from it, and on the other, to look for methods to control the amount of methane released. We see research gaps in these areas. On the basis of the research gap identified, we formulated the main goal of our research, which is: to build a model for the programming of mine production in hard coal mines taking into account the control of the amount of methane released into the atmosphere. To achieve this goal, we stated the following research questions (RQ):

Background (…) In my opinion, authors should use the proper correct carbon dioxide (CO2) entry with subscript 

We used subscript for CO₂

Study method: In my opinion, the authors use the wrong numbering of the formulas (2 and 3 should be 1a, 1b) because these formulas (2 and 3) are inextricably linked to formulas The same remarks are for formulas 4, 5, 6, where 5 and 6 are strongly linked with 4, so “a”, “b”.

We used “a”, “b” etc. for formulas

Discussion: I believe the text from the discussion should be in the analysis, after the final econometric model. .

The test about JSW was added to results (analysis), and discussion started from: At the present ….

The discussion should be rewritten, referencing research and literature and methane control methods

The discussion is rewritten

Are the conclusions thoroughly supported by the results presented in the article or referenced in secondary literature?

Can be improved

The conclusions in the article have been corrected

Are the research design, questions, hypotheses and methods clearly stated?

Can be improved

In the added text there is hypothesis:

We think that the problem is not well known because researchers mainly concentrate their analysis on key renewable energy sources. However, we think the problem of methane is a very interesting and scientifically important research gap, especially in the deep decarbonisation. We should know what these economies like Poland, where mines are still key suppliers of energy sources, are up to. The extraction activities of mines are accompanied by released methane. On the one hand, there is a need to focus on methods for recovering methane and producing energy and heat from it, and on the other, to look for methods to control the amount of methane released. We see research gaps in these areas. On the basis of the research gap identified, we formulated the main goal of our research, which is: to build a model for the programming of mine production in hard coal mines taking into account the control of the amount of methane released into the atmosphere. To achieve this goal, we stated the following research questions (RQ):

RQ1. What are the political requirements for decarbonisation of mines?

RQ2. What are the technological directions (is the path) for methane recovery?

 RQ3. What indicators should be used to build the objective function to make the model          quickly applicable?

In the paper we present an econometric model for mine production programming, taking into account both market considerations and controlling the amount of methane released into the air from mines.

Our research set out the following research hypothesis (RH): it is possible to use mining production programming methods in an operational planning system to control the amount of methane released into the atmosphere from a group of pits or mines. At the same time, the aim of developing an econometric model was to use easy and low-cost tools to support management decision-making. This work consists of a theoretical part and a research part. The paper is structured as follows. It starts with an introduction (section 1), followed by section 2 presenting the background of decarbonisation. Section 3 provides information on the method of the study. Section 4 presents the results of our analysis, which is an econometric model. A discussion of our findings is provided in Section 5. Section 6 provides conclusions and limitations, as well as directions for future research.

The theoretical part was based on a literature review. The research part was a result of econometric modelling. The literature part was created in accordance with the SLR methodology using the keyword "Decarbonisation coal". The research area on the recovery of methane, which is a greenhouse gas, was identified from this collection. Methane emission has a 25 times greater impact on the greenhouse effect (per unit mass) than carbon dioxide. Using methods to capture them and use them in the energy production process is one of the scenarios for Polish coal mines [5].

Therefore, the search for methods of capturing methane from mine air is the subject of many studies. The authors drew attention to a different approach to the problem - the optimization of methane emissions during coal mining by controlling the volume of extraction, while taking into account market requirements and meeting the current demand for given assortments.

The research part - the econometric model - was created on the basis of data obtained from Polish coal mines. Appropriately coded and modified to present the universality of the model. It can be used for planning activities at coal mines in the area of greenhouse gas emission reduction policy.

page 4, second line: Correct wording: "Other..."

There is now a big letter

page 6, second line: Correct wording: "...in 2018 7%...

We changed:

In 2018 mining industry in the Silesian Region in Poland created 7% of added value [57].

page 6, fifth line of second paragraph: Correct wording: "...of PEP 2010..."

in English:

·      

Energy Policy of Poland until 2040 (EPP2040)

so we used two forms:

in Polish: Polityka Energetyczna Polski PEP2040

and in English: Energy Policy of Poland

EPP2040

page 6, table 3: Correct wording: "... PEP 2040..."

Source: Energy Policy of Poland EPP2040 (abbreviation in Polish: PEP2040) [58].

page 9, second line of second paragraph: Correct wording: "...similar coal quality..."

of course

coal

page 9, paragraph under relation (9): Correct wording: "...the coal going..."

of course

coal

page 11, second line of Conclusion: Correct wording:: "...mining operation from..."

We changed/ dot removed

Coal mine methane (CMM) is the term given to methane produced or emitted in connection with coal mining operations from the coal seam itself or from other gas-bearing formations underground.

Are the arguments and discussion of findings coherent, balanced and compelling?

Can be improved

The discussion was extended based on other scientific articles. Extending the argumentation for the use of the proposed model.

Are the conclusions thoroughly supported by the results presented in the article or referenced in secondary literature?

Can be improved

Conclusions was improved

Issue 1

-

Issue 2

Introduction was changed according to reviewer 2.

According to your suggestion, the next text was added:

the penultimate paragraph of Chapter 1

Please provide answers for important questions regarding methodology and provide lines where it is discussed in the paper:

To introduction was added the following text:

We think that the problem is not well known because researchers mainly concentrate their analysis on key renewable energy sources. However, we think the problem of methane is a very interesting and scientifically important research gap, especially in the deep decarbonisation. We should know what these economies like Poland, where mines are still key suppliers of energy sources, are up to. The extraction activities of mines are accompanied by released methane. On the one hand, there is a need to focus on methods for recovering methane and producing energy and heat from it, and on the other, to look for methods to control the amount of methane released. We see research gaps in these areas. On the basis of the research gap identified, we formulated the main goal of our research, which is: to build a model for the programming of mine production in hard coal mines taking into account the control of the amount of methane released into the atmosphere. To achieve this goal, we stated the following research questions (RQ):

RQ1. What are the political requirements for decarbonisation of mines?

RQ2. What are the technological directions (is the path) for methane recovery?

 RQ3. What indicators should be used to build the objective function to make the model          quickly applicable?

In the paper we present an econometric model for mine production programming, taking into account both market considerations and controlling the amount of methane released into the air from mines.

Our research set out the following research hypothesis (RH): it is possible to use mining production programming methods in an operational planning system to control the amount of methane released into the atmosphere from a group of pits or mines. At the same time, the aim of developing an econometric model was to use easy and low-cost tools to support management decision-making. This work consists of a theoretical part and a research part. The paper is structured as follows. It starts with an introduction (section 1), followed by section 2 presenting the background of decarbonisation. Section 3 provides information on the method of the study. Section 4 presents the results of our analysis, which is an econometric model. A discussion of our findings is provided in Section 5. Section 6 provides conclusions and limitations, as well as directions for future research.

The theoretical part was based on a literature review. The research part was a result of econometric modelling. The literature part was created in accordance with the SLR methodology using the keyword "Decarbonisation coal". The research area on the recovery of methane, which is a greenhouse gas, was identified from this collection. Methane emission has a 25 times greater impact on the greenhouse effect (per unit mass) than carbon dioxide. Using methods to capture them and use them in the energy production process is one of the scenarios for Polish coal mines [5].

Therefore, the search for methods of capturing methane from mine air is the subject of many studies. The authors drew attention to a different approach to the problem - the optimization of methane emissions during coal mining by controlling the volume of extraction, while taking into account market requirements and meeting the current demand for given assortments.

The research part - the econometric model - was created on the basis of data obtained from Polish coal mines. Appropriately coded and modified to present the universality of the model. It can be used for planning activities at coal mines in the area of greenhouse gas emission reduction policy.

To the discussion the following text was added:

The EU's ever-improving circular economy policy [69] (the European Union is working on proposals to help move towards a stronger closed-loop economy, in which resources are used more sustainably and production substances are reused) can help mines build a methane recovery and processing system [70]. A key role in methane recovery is the possibility of using it as a heat and energy source (methane can be used in gas turbines to produce electricity and heat). Methane can help mines build a new energy and heat supply chain and save energy in economy. The benefits of a more sustainable mining industry also include new and innovative revenue streams (money from its use of methane in industry). The capture of methane from closed mines can - and should - be an important addition to the national energy mix.

In the light of the new direction of the EU in the field of methane emissions (a regulation that introduces a methane emission standard of 5 tons of this gas per 1,000 tons of mined coal; a regulation introduced from 2027, and in 2031 a standard for coking coal mines), coal mines forms of response to these commitments. This is especially important when we know that 90% of methane emissions reports in Poland come from hard coal mines. Methane emission is appropriate to the mining and geological conditions of the exploited seams. Therefore, the size of the limit by 28% in 2021 compared to 2011. The direct approach to methane emissions does not take into account the specificity of the industry and the natural conditions of the coal deposits that manage the coal lines are not affected. Therefore, looking for methods to reduce or optimize the amount of released methane meets their needs. Operation and scientific research are carried out in two versions: developing a method of capturing methane from the release of mine air and optimizing the amount of methane for coal extraction alone.

Greenhouse gas emissions, which include methane, are particularly important in the light of the climate policy of the International Panel on Climate Change (IPCC, 2021). This is important for the development of all EU countries [71].

Methane not only pollutes the air, but also affects the amount of ozone in the atmosphere. During the period of rising to the level of Los Angeles-type smog, which contributed to death, therefore, the expulsion of methane has side effects, economic and social.

The European Commission has set two directions for the main tasks [72]:

• Reform of the reporting system - in the discussed topic, it is a higher task of the Mining Office,

• Control of material and emissions from coal mines – this aspect is a proposed econometric model.

Attention should also be paid to the existing problems with the unification of methane emission data reporting. Repeatedly, data is duplicated and misreporting can occur. A large number of reporting entities has a large impact on this state.

As a result of 1, thanks to which the amount of methane emission is variable and depends on the parameters of the mined seams. Therefore, the proposed model takes into account such parameters as well as economic and environmental parameters.

The model focuses on measurable parameters at the level of mines and allows for a relatively effective modeling of methane emissions. Calculation of methane emissions for a group of mines or the entire mining industry is extremely difficult due to reporting problems. Therefore, the search for methods and tools to optimize methane emissions "at source" is part of the general trend of building cleaner production systems (CP).

Issues 3

What specific variables and parameters were considered in the econometric model developed for the Polish mining industry to analyze the configuration path of decarbonization based on Coal Mine Methane (CMM)?

added in Chapter 3

Issue from 4 to 7, 9, 10

All reviewer comments have been taken into account and added in Chapter 3

Issue 8

We added in discussion Chapter 5:

The EU's ever-improving circular economy policy [69] (the European Union is working on proposals to help move towards a stronger closed-loop economy, in which resources are used more sustainably and production substances are reused) can help mines build a methane recovery and processing system [70]. A key role in methane recovery is the possibility of using it as a heat and energy source (methane can be used in gas turbines to produce electricity and heat). Methane can help mines build a new energy and heat supply chain and save energy in economy. The benefits of a more sustainable mining industry also include new and innovative revenue streams (money from its use of methane in industry). The capture of methane from closed mines can - and should - be an important addition to the national energy mix.

[70] Markevych, K.; Maistro, S.; Koval, V.; Paliukh, V. Mining sustainability and circular economy in the contest of economic security in Ukraine. Min. Miner. Depos. 2022, 16, 101-113.

Issue 12

To concussion the following text was added:

Coal mine methane (CMM) is the term given to methane produced or emitted in connection with coal mining operations from the coal seam itself or from other gas-bearing formations underground. The amount (…)

(…)

The applied linear programming method does not require any additional software. It is so intuitive that it can be quickly implemented and used in hard coal mines. This is of particular importance due to the organizational culture prevailing in these mining plants. However, this model will require testing on selected mines and verification of emerging mining and organizational restrictions. Further research will be carried out in this direction. From linear programming you can move to complex multivariate econometric models. From linear programming you can move to complex multivariate econometric models. The planned, future scope of research will concern the optimisation of methane management in mines. The authors plan to use two analysis segments: segment 1 will concern mines excluded from coal production, and segment 2 will concern active mines. The obtained models will be used to forecast the variables under study until 2049, i.e. until the mines in Poland are closed for mining (hard coal mining) according to Polish Energy Policy [58].

Refereces:

twelve papers were added:

According to the text about restructuring traditional industries in Poland

and circular economy, including

Markevych, K.; Maistro, S.; Koval, V.; Paliukh, V. Mining sustainability and circular economy in the contest of economic security in Ukraine. Min. Miner. Depos. 2022, 16, 101-113.