Sustainable Development in the Colombian Post-Conflict—The Impact of Renewable Energies in Coffee-Growing Women

There are some inaccurate expressions and repetitions within the text.

The text was reviewed

You should also use more recent references (2021-2022)

Despite the fact that there are other bibliographical references, this study is focused on a very specific rural territory. That is why the bibliography used is the one we have available at the moment.

The conclusions are consistent, but need to be strengthened. 

The conclusions were strengthened

We need to review (4.2.2 Role of Women in the Coffee Sector)

This section has been reviewed and it has been moved ton Materials and Methods:

2.3. Role of Women in the Coffee Sector

Also an interesting aspect could be to evaluate the strengths and weaknesses of the article.

The strengths and weaknesses of the article are mentioned in section 6, Directions for future research

The article lacks a subsection on literature overview, and the research also lacks conducting statistical research in addition to presenting the results of surveys.

We had a problem with the Appendix.

Now, we have uploaded 3 supplementary materials:

Appendix A. Technical specifications of the questionnaire

Appendix B. Results of telephone interview

Appendix C. Geographical ubication of installed biodigesters

Also missing is an indication of the limitations of the research

The limitations of the research are mentioned now in section 6. Directions for future research

as well as a comparison of the results with other authors, and an indication of significant contributions to science. 

Despite the fact that there are other bibliographical references, this study is focused on a very specific rural territory. That is why the bibliography used is the one we have available at the moment. It is not our aim to make a comparison with other cases.

Abstract.

English needs to be improved.

Abstract has been reviewed

Lines 27-28: “biodigester can produce between 1.362 and 1.597 kg/day”.

Are you sure of the unit of measurement used? In particular, if you were talking about biogas, I would expect the volume per day.

Furthermore, 1.362 and 1.597 are not mentioned in the main manuscript.

Abstract and lines 337-338

is introduced the biogas production in kg/day and Nm³/day

1.362 and 1.597 kg/day are equivalent to 1.170 and 1.360 Nm³/day (P=101.325 KPa; T=273.15 K)

Line 40: “12.6 million 60-kilo bags”.

Please, recheck it. It is unclear to me.

Lines 43-44: 12.6 million 60 kilo-bag/year. (756.000 Ton/year)

From line 47: “Coffee production and farms activities are a source of waste production…”

In this paragraph or the following ones, you should also elaborate on the type and amount of waste produced in the coffee sector. You should share information on a global scale and then go into the matter in Colombia.

Line 65-68..

In the post-harvest coffee process, wet and dry methods are used for the production of green coffee as the final commodity. In the project area, the wet method is widespread. This method generates the following wastes: pulp (43%), mucilage (27%) and husk (6%) [15].

From line 83: “The study was conducted in the department of Tolima…”

Please, provide more information about the location.

From line 100: “specifically, in rural villages of the municipality of Chaparral, in the south of this region.”

We have added an Appendix C. Geographical ubication of installed biodigesters

Lines 90-91: “information was gathered from 551 coffee production units (CPUs) in 13 of the 47 municipalities in Tolima”.

Is it possible to show it on a map?

We have added an Appendix C. Geographical ubication of installed biodigesters

Line 102: “by Mendoza [19]”.

You must write “by Mentoza et al. [19]”. Indeed, the reference you cited has many authors.

This has already been modified.

Section 2.1.2 Characteristics of the Biodigesters and Thermal System, 2018.

Please, provide a figure or a layout of the system. Otherwise, highlight that more details will be given in the results section (indeed, I noticed that my request corresponds to Figure 3).

From Line 380:

The biogas produced contains an average of 53.5% CH₄ and has an energy content of 5.33 kWh/m³.  This is a renewable energy that can be used in cooking in rural areas for a family of 5 people or can be used as a additional source energy for coffee drying.

Line 146: “The instrument included 32 questions covering the following dimensions”.

Please, show the questions. You could include such information in the Supplementary Materials of the manuscript.

We have included Appendix A with the technical description of the questions

Lines 153-156: “According to the analysis conducted by experts using the analytic hierarchy process, the criteria of attitude toward change and keeping of animals, with values of 22.04% and 20.25% respectively (Figure 1), represent aspects with the most weight in the selection model.”

It is not very clear. Please, reformulate the sentence. 

From line 302: “Animal excreta, together with coffee wastewater from coffee processing (mucilage + water), are introduced into the biodigester for organic material to be broken down through the anaerobic co-digestion process”

Lines 158-159: “waste from coffee processing”.

It would help provide more details about such waste. You should summarise the information somewhere in the materials and methods section.

From line 302:

Animal excreta, together with coffee wastewater from coffee processing (mucilage + water), are introduced into the biodigester for the organic material to be broken down through the anaerobic co-digestion process

Figure 2.

The figure needs to be discussed better in the manuscript. 

The description in figure two was improved.
From line 313:

Figure description in the text: “Figure 2 shows the 551 CPUs studied and the thermal system beneficiaries (red dots), in addition to the municipalities involved in the project (y-axis). To select them, a decision threshold (solid line) was taken into account. This threshold was established based on the sum of the percentages of the most relevant criteria (attitude toward change and keeping of animals) ...”
Figure description in the title:
From line 328:

“Figure 2. Final classification of producers involved in the project. The y-axis are the municipalities and the x-axis are the score. The solid line is the qualification threshold and the red dots are the benefited CPUs.”

Line 191: “Figure X3”.

You must write “Figure 3”.

This has been already modified.

Lines 200-201: “it was found that the biodigesters continue to operate in 8 of the 11 CPUs surveyed”.

After how long?

From line 391

Upon the application of the instrument, it was found that the biodigesters continue to operate in 8 of the 11 CPUs surveyed, after 18 months of installation

Lines 205-206: “According to the data found in the interviews, the average time spent on food preparation tasks decreased by two hours per day since the biodigesters’ installation”.

Please, summarise the results of your interviews in a Table or (if too long) in supplementary materials. It would also be helpful to mention the percentage and significance of the results.

We have added an Appendix A: Technical specifications of the questionnaire and an Appendix B: Results of the telephone interview

Lines 208-210: “Furthermore, women expressed their satisfaction with the fact that the production of biogas favors take care of the environment, a key aspect when it comes to promoting cleaner and more sustainable coffee production.”

See my previous comment.

We have added an Appendix A: Technical specifications of the questionnaire and an Appendix B: Results of the telephone interview

Line 198: “Table X1”.

You must write “Table 1”.

This has been already modified.

Weaknesses identified in section 3.

You should provide information about the hydraulic retention time of waste (and water) in the biodigesters. Furthermore, some information about the waste inflow and the digestate outflow (sludge) is necessary, both quantitative and qualitative. 

In addition, have you collected any information about the pathogen's content? Do you treat the digestate outflow in some way? What is the fate of the digestate (sludge)?

Line 206 - 211

The biodigester has a hydraulic retention time (HRT) between 30 and 35 days, according to the feeding frequency of the substrate. The substrate is supplied in a ratio of 3:1 of water: mix of organic waste. The average annual temperature in the biodigester installation area is 25 °C at a maximum temperature of 31 °C and a minimum temperature of 17 °C. They are located in a rural mountainous area with altitudes between 1500 and 1700 meters.

Microbiological analyses of the bioreactor effluent were not performed as part of the research work.  They were left for a later investigation on the evaluation of the performance and operation of the biodigester. Microbiological analyses of the bioreactor effluent were not performed as part of the research work.  They were left for a later investigation on the evaluation of the performance and operation of the biodigester

Lines 231-232: “biogas mass, which reached a production of between 1,362 and 1,597 kg/day—enough energy to cook food for a four-person family [24].”

I am not sure about the appropriateness of measuring “biogas mass”. Indeed, it is more common to consider daily biogas production in terms of volume/day. 

Furthermore, your statement about “energy to cook food for a four-person family” appears too vague. Indeed, for every biodigester, you should consider the biogas generation per day. Thus, you should consider how much biogas a cooking stove consumes per hour. In this way, it will be possible to estimate how long you can cook each day using the biogas produced. Of course, you will obtain average values (considering that every family has a different number of people as well as different habits).

Lines 337-338:. is introduced the biogas production in kg/day and Nm³/day

1.362 and 1.597 kg/day are equivalent to 1.170 and 1.360 Nm³/day (P=101.325 KPa; T=273.15 K)

Lines 245-247: “On average, LPG consumption was reportedly reduced by approximately 50% in CPUs where a biodigester was installed and the gas produced was used for cooking.”

Please, share such data in a Table or Supplementary Materials.

We have added an Appendix A: Technical specifications of the questionnaire and an Appendix B: Results of the telephone interview

Lines 252-255: “Health benefits for women and children are reflected in less exposure to smoke from wood stoves and, as a result, the respiratory illnesses this entails, as reported in the results of other studies conducted on the subject [26].”

The topic should be discussed better. Indeed, although positive health outcomes have been demonstrated in reducing air pollution, other adverse health outcomes cannot be underestimated. In particular, when using waste with a high potential for pathogens (such as animal faeces). Indeed, some authors found that, although biodigester cookstoves can reduce household air pollution, children’s diarrhoea may be an unintended health risk when human and animal sludges are used. In these cases, some countermeasures to reduce risks can be taken. You can find more details here (feel free to use such publications or not; it was just to give you some clues):

From line 448: “However, it should be noted that although positive health outcomes have been demonstrated in reducing air pollution, other adverse health outcomes cannot be underestimated. In this sense, there are some studies that show that the use of waste with potential for pathogens can be also harmful in terms of health. It is true that biodigester cookstoves can reduce household air pollution, but, on the contrary, when human and animal sludges are used, it can produce children’s diarrhea.”

Lines 296-297: “After several years of the COVID-19 pandemic’s impact”.

I think it is excessive to write “after several years” because the pandemic started in 2020, i.e. not so long ago.

This has been already modified.

Appendix A.

The Appendix was not available. Thus, it was impossible to read and check it. Please, provide it.

Now is Appendix B.

Section 4.2.2 Role of Women in the Coffee Sector.

The section has crucial information. However, most (or even all) of the section should be in the Introduction or the Materials and Methods section. Indeed, it provides essential background information.

This section is now in Materials and Methods:

2.3. Role of Women in the Coffee Sector

Section 5. Conclusions.

Future research and perspectives should also be discussed.

Future research is mentioned now in section 6. Directions or future research