Biorefinery of Beach Cast Seaweed in Brazil: Renewable Energy and Sustainability

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Paper deals with a very important task in the field of bioenergy. The experiment described in the paper was very thorough and comprehensive, and the obtained results were described very well. Therefore, I recommend publishing this paper.

Author Response

REVSOR 1

Paper deals with a very important task in the field of bioenergy. The experiment described in the paper was very thorough and comprehensive, and the obtained results were described very well. Therefore, I recommend publishing this paper.

RESPONSE: We thank the noble reviewer for considerations about our article.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The presented work is of an applied nature, but corresponds to the scope of the journal. However, there are a number of comments regarding the work:

1. The introduction and discussion do not compare the algal biomass values of Brazil with other areas. The authors are mistaken that the biomass of algae in other areas of the world's oceans has been little studied. Such work was actively carried out in the 70-90s of the last century, and there are also modern studies.

2. The use of algae as fuel during combustion can be discussed in the context of waste generated after the extraction of biologically active substances. The authors touched on this aspect little.

3. Conclusions must be drawn based on the results of the work for the specifically studied location/locations, and to discuss the results, a comparison with those previously obtained by other authors can and should be used. In this work, too general conclusions are drawn on scant local material.

4. It is necessary to pay more attention to the design of tables and figures. There is redundant information in the figures; the tables must also be carefully designed (table 6, for example, has broken columns).

Author Response

REVISOR 2

The presented work is of an applied nature, but corresponds to the scope of the journal. However, there are a number of comments regarding the work:

1. The introduction and discussion do not compare the algal biomass values of Brazil with other areas. The authors are mistaken that the biomass of algae in other areas of the world's oceans has been little studied. Such work was actively carried out in the 70-90 of the last centuries, and there are also modern studies.
2. The use of algae as fuel during combustion can be discussed in the context of waste generated after the extraction of biologically active substances. The authors touched on this aspect little.
3. Conclusions must be drawn based on the results of the work for the specifically studied location/locations, and to discuss the results, a comparison with those previously obtained by other authors can and should be used. In this work, too general conclusions are drawn on scant local material.
4. It is necessary to pay more attention to the design of tables and figures. There is redundant information in the figures; the tables must also be carefully designed (table 6, for example, has broken columns).

RESPONSE:

Dear reviewer, we thank you for contributions to improvement article.

1. In his initial observation we added text and link [72], in the topic "RESULTS AND DISCUSSIONS", page 4, lines 193-196, analysing comparative results of biomass in Brazil, but as we stated at the end of Introduction, there are very few sampling works on deposition macroalgae biomass in Brazil and there is none that has been done in a period of 2 years with 28 collections in 7 beaches. Regarding his second observation, we mention authors declare few works about sampling macroalgae biomass deposition [4,21,22]. Indeed, we not identify a lot of manuscripts with sampling references, otherwise, we confirm there are many energy studies with macroalgae biomass in the world. It’s necessary separate different researches.

2. On page 11, lines 378-381, we warn concern for environment regarding lignin residues generated by binder additives caused by combustion pellets, including chemical reaction of elements in this process. On page 13, between lines 410 - 413, we add text on environmental aspects caused by macroalgae ashes, with citation of two new authors and their respective bibliographic references [73,74].
3. In the topic "CONCLUSION" we highlight three important results for the article: The sustainability and availability of biomass energy use – 5.03 Kg/ha; the calorific value aggregate biomass of macroalgae, similar to main biomass energy generation in Brazil – 8.82 MJ/Kg, and finally, we highlight results of pellets calorific value with 20.19 MJ/Kg – HCV, having an average higher than terrestrial biomass pellets. To discuss the results, we used 40 citations of authors with their respective bibliographic references.
4. Dear reviewer, I believe it is formatting problem, when the file is converted to PDF format the columns staying accurate, however, were corrected Table 6, according your guidance and updated to better visibility.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The experimental paper “BIOREFINERY OF BEACH CAST SEAWEED IN BRAZIL: RENEWABLE ENERGY AND SUSTAINABILITY” evaluates the production of biofuel from seaweed. The work is aimed at the possibility of creating another sustainable alternative to the energy problem while reducing environmental problems. The authors examine the chemical composition of macroalgae and evaluate their calorific value and energy potential, as well as assess the sustainability of algae biomass production. The authors know the terminology and understand the topic, so the article is well written and can be published in the journal Phycology after eliminating a number of comments.

1. There was some confusion in the numbering of links in the introduction (link 2, then immediately 29, 60, 70). Needs to be fixed.

2. In the introduction there is only one reference from 2022, there are no references from 2023 at all. It is recommended to strengthen the relevance of the work by including more recent publications (2022-2024) on this topic in the introduction.

3. Lines 111-116. You need to add the appropriate links to the tests.

4. Clause 2.3.1. Why did the authors choose corn oil as a binder and why do they use this particular ratio of oil to biomass? Please explain or supplement with a link to relevant research.

5.Figure 3 is hard to read, the quality needs to be improved.

6. Lines 230-241. Confusion with link numbering. It is necessary to check the numbering of references throughout the text.

7. Lines 446-463. It is not entirely clear what conclusions the authors draw when discussing the composition of macroalgae. If possible, it should be rewritten.

Author Response

REVISOR 3

The experimental paper “BIOREFINERY OF BEACH CAST SEAWEED IN BRAZIL: RENEWABLE ENERGY AND SUSTAINABILITY” evaluates the production of biofuel from seaweed. The work is aimed at the possibility of creating another sustainable alternative to the energy problem while reducing environmental problems. The authors examine the chemical composition of macroalgae and evaluate their calorific value and energy potential, as well as assess the sustainability of algae biomass production. The authors know the terminology and understand the topic, so the article is well written and can be published in the journal Phycology after eliminating a number of comments.

1. There was some confusion in the numbering of links in the introduction (link 2, then immediately 29, 60, 70). Needs to be fixed.
2. In the introduction there is only one reference from 2022, there are no references from 2023 at all. It is recommended to strengthen the relevance of the work by including more recent publications (2022-2024) on this topic in the introduction.
3. Lines 111-116. You need to add the appropriate links to the tests.
4. Clause 2.3.1. Why did the authors choose corn oil as a binder and why do they use this particular ratio of oil to biomass? Please explain or supplement with a link to relevant research.
5. Figure 3 is hard to read; the quality needs to be improved.
6. Lines 230-241. Confusion with link numbering. It is necessary to check the numbering of references throughout the text.

Lines 446-463. It is not entirely clear what conclusions the authors draw when discussing the composition of macroalgae. If possible, it should be rewritten.    

RESPONSE

Dear reviewer, we thank you for contributions to improvement article.

1. The authors' numerical citations in the text correspond to linear and sequential numerical order for authors' bibliographic references (pp. 15-18). Note that order numbers text citations are determined by context of subjects covered, which are referenced numerically and consecutively in the bibliographic references.
2. We clarify that in INTRODUCTION there is quote author 2023 at the link [70] and in text course there are five more quotes from this year. Considering there are several citations from 2020 to 2022, I think the article refers to current state of scientific research in this area. We also understand that it is essential to understand techniques evolution, practices and technologies from the past, that allow to understand actual scientific progress research. The trends and processes are analysed trough interactivity between renewable energy and Phycology studies.
3. According to reviewer's observations, we added four new authors regarding statistical data and research: [75,76,77,78], page 5.
4. The choice of corn oil was due sustainability of this agricultural genre, since Brazil is the world's third largest producer of corn, enabling greater availability of raw material with low production costs. Corn oil can add nutritional value to pellets produced without negative environmental impacts that could interfere at production process. (The text has been added to the article on page 11, lines 378-381.)
5. We've improved sharpness and contrast of graph image in Figure 3, making font bigger and easier to see.
6. Changed and corrected numbering of link [26] to [43,44], line 213
7. The text was rewritten and changed on page 13, lines 410-413

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

 

BIOREFINERY OF BEACH CAST SEAWEED IN BRAZIL: RENEWABLE ENERGY AND SUSTAINABILITY

The authors conducted two studies to assess the sustainability of macroalgae biomass for biorefinery purposes. The first study involved collecting macroalgae deposition from seven beaches along the Maceió coast over a period of two years, with a total of 28 collections. The samples were collected using a zigzag sampling method, encompassing a deposition area of 135 0001 m². The findings indicate a dry biomass yield of 5.03 ton/ha through daily collection. b) The power calorific value and compound of energy macroalgae biomass pellets.

 

Rewrite the abstract with a trend and flow in mind to help readers understand it better.

Authors have collected lot of data, however…..

The study needs more clarity in its sentence and paragraph structure. Authors are encouraged to reframe sentences and paragraphs, establishing connections to construct an integrated summary of the findings clearly and straightforwardly.

 

The abstract and title should be informative to convey the meaning of the work accurately.

 

Authors need to revise the manuscript.

 

Comments

 

·         The main aspect that differentiates the productivity of respective biomasses can be considered because sugar cane collection is realized after eighteen months while macroalgae collection is daily- What about the consistency in deriving biomass, specifically from macroalgae?

·         Advantages like macroalgae raw material collected in coastal region by free process without agricultural costs, inputs or irrigation, find opposition to relative costs like washing processes, sea sand decantation, separating rubbish residuals, biomass drying machines and worker team to get collect every day-apart from seasonal variations, what are the other factors that mostly influence the macroalgae.

·         Ponta Verde and Jatiúca beaches showed similar proportional losses, and Pajuçara beach reached high rate with water losses; the difference occur due accumulation water in some points of continental shelf formation with different elevation in some parts coastal terrain; which can manifesting unequal water flow tidal movement at time collection, where the biomass becomes more humid or dry at some points of beach coast line- does these environmental variations effect the Calorific Value and output energy

·         This feature makes macroalgae biomass requires less energy to develop those terrestrial plants it means promotes the advantage of growing faster than any terrestrial plant species- Is the photosynthetic efficiency of marine macroalgae the only factor responsible for their rapid growth? Are there any additional factors that impact the photosynthetic efficiency of marine macroalgae?

·         The abstract and title should be informative to convey the meaning of the work accurately.

 

 

 

Author Response

REVISOR 4

BIOREFINERY OF BEACH CAST SEAWEED IN BRAZIL: RENEWABLE ENERGY AND SUSTAINABILITY

The authors conducted two studies to assess the sustainability of macroalgae biomass for biorefinery purposes. The first study involved collecting macroalgae deposition from seven beaches along the Maceió coast over a period of two years, with a total of 28 collections. The samples were collected using a zigzag sampling method, encompassing a deposition area of 135 0001 m². The findings indicate a dry biomass yield of 5.03 ton/ha through daily collection. b) The power calorific value and compound of energy macroalgae biomass pellets.

Rewrite the abstract with a trend and flow in mind to help readers understand it better.

Authors have collected lot of data, however…..

The study needs more clarity in its sentence and paragraph structure. Authors are encouraged to reframe sentences and paragraphs, establishing connections to construct an integrated summary of the findings clearly and straightforwardly.

The abstract and title should be informative to convey the meaning of the work accurately.

Authors need to revise the manuscript.

Comments

The main aspect that differentiates the productivity of respective biomasses can be considered because sugar cane collection is realized after eighteen months while macroalgae collection is daily- What about the consistency in deriving biomass, specifically from macroalgae?

Advantages like macroalgae raw material collected in coastal region by free process without agricultural costs, inputs or irrigation, find opposition to relative costs like washing processes, sea sand decantation, separating rubbish residuals, biomass drying machines and worker team to get collect every day-apart from seasonal variations, what are the other factors that mostly influence the macroalgae.

Ponta Verde and Jatiúca beaches showed similar proportional losses, and Pajuçara beach reached high rate with water losses; the difference occur due accumulation water in some points of continental shelf formation with different elevation in some parts coastal terrain; which can manifesting unequal water flow tidal movement at time collection, where the biomass becomes more humid or dry at some points of beach coast line- does these environmental variations effect the Calorific Value and output energy

This feature makes macroalgae biomass requires less energy to develop those terrestrial plants it means promotes the advantage of growing faster than any terrestrial plant species- Is the photosynthetic efficiency of marine macroalgae the only factor responsible for their rapid growth? Are there any additional factors that impact the photosynthetic efficiency of marine macroalgae?

The abstract and title should be informative to convey the meaning of the work accurately.

RESPONSE

Dear Reviewer,

We appreciate your analysis and contribution to article improvement. Among the points raised by your observations, considering our understanding follow up.

Abstract and title: We conclude that title clearly states the intention of using macroalgae biomass for energy purposes, contributing to development technologies in renewable energies area, thus configuring greater sustainability for the energy issue. We consider that the abstract clearly expresses the objectives of this research, the methodology and the main results achieved.

Authors need to proofread the manuscript: the reviewer's placement is accurate and coherent. We made several modifications to the text as specified in the document sent to the reviewers and added new citations and bibliographic references.

The main aspect that differentiates the productivity of the respective biomasses can be considered because the collection of sugarcane is carried out after eighteen months, while the collection of macroalgae is daily. What about consistency in obtaining biomass, specifically macroalgae? The removal of biomass is licensed by the Municipal Department of Urban Development and Sustainability Maceió city. The availability of biomass happens naturally every day with deposition of algae washed up on the coast Maceió city, according to the methodological description in the collection processes. The statistical results confirm high grade of biomass deposition.

Advantages such as raw material of macroalgae collected in the coastal region by free process, without agricultural costs, inputs or irrigation, find opposition to relative costs such as washing processes, decantation of sea sand, separation of waste from garbage, biomass drying machines and team of workers for collection on alternate days of seasonal variations, what are the other factors that most influence macroalgae? In the growth of macroalgae, abiotic factors are the most influential; water temperature, nutrients, salinity, solar radiation and seasonality. These points are explained in topic 3.3. Factors of macroalgae deposition. (page 7)

The beaches of Ponta Verde and Jatiúca presented similar proportional losses, and the beach of Pajuçara reached a high rate of water losses; the difference occurs due to the accumulation of water at some points of the formation of the continental shelf with different elevations in some parts of the coastal terrain; which may manifest unequal tidal movements of the water flow at the time of collection,  Where the biomass becomes wetter or drier at some points on the beach shoreline – do these environmental variations affect the calorific value and energy output? No, these environmental variations do not alter calorific value of biomass.

This characteristic makes the biomass of macroalgae require less energy to develop land plants, which means that it promotes the advantage of growing faster than any species of land plant. Is the photosynthetic efficiency of marine macroalgae the only factor responsible for their rapid growth? Are there any additional factors that impact the photosynthetic efficiency of marine macroalgae?

No, photosynthetic efficiency is not the only factor that interferes with macroalgae growth; amount of nutrients available in the water and abiotic factors mentioned above can favour or hinder macroalgae growth. Other additional factors impact efficiency as availability water, macroalgae do not have water stress like terrestrial plants, abundance of oxygen and tropical climates where the rate of insolation is high, with more hours of sunshine for photosynthesis. These points are explained in topic 3.3. Factors of macroalgae deposition (page 7).

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors did not take into account the reviewer’s comments and did not make appropriate changes to the text, figures and tables of the article.

Author Response

Dear Reviewer,

We thank and praise your stance in pursuing improvement to scientific best research results. Clarifying and meeting your demand, we ask that emeritus reviewer that "INTRODUCTION", page. 1, lines 54-57, appoint insertion text referring to bibliographic research in the link [25]. The aforementioned scientific article reports biomass data comparable to achieved results. In "RESULTS and DISCUSSIONS" changes text were made on page. 4, lines 194 - 199 (yellow highlighted). Regarding your demand to improve table 6, regarding columns, this was done as highlighted on page. 13, line 419. We reviewed all tables and graphs, where tables 4,5,6 and 7, columns were formatted for better visualization and get performance publication. All changes were done with yellow highlighted. We hope to have understood your questions, but if need something else, it doesn't matter, we are ready to complete this article with excellence.

Sincerely,

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The article has been thoroughly reviewed by the authors, considering all the comments. No further comments from my side. The manuscript may be considered for publication. 

 

Author Response

Dear reviewer, we thank your contribution to improving our article. We hope to reiterate our commitment to increasingly scientific knowledge in favor of sustainability and more balanced society. 

Author Response File: Author Response.pdf