Comparison of Biochar Materials Derived from Coconut Husks and Various Types of Livestock Manure, and Their Potential for Use in Removal of H2S from Biogas
, Mei Chen 1, Guihua Zhuo 2, Rongting Ji 1, Saier Wang 1,*, Longjiang Zhang 1, Mingzhu Zhang 1,* and Haidong Li 1Round 1
Reviewer 1 Report
Dear Authors
It was a real pleasure for me to read Yours paper, especially that I find its subject particularly interesting. Having read the article thoroughly, I would like to recommend it for publication in Sustainability Journal. As far as the text itself is concerned, well written in terms of both its science and the editorial side. In a few fragments, however, there will be a problem with the uniform text format - the spacing between the lines is different
The critical remark I have, though it shall by no means deteriorate the value of the article, is that the all figures and the fonts used in the figures should be corrected, because the fonts on the figures are too small. Moreover all figures should be presented with larger resolution - they are currently very blurred.
Author Response
Response to Reviewer 1 Comments
Point 1: It was a real pleasure for me to read Yours paper, especially that I find its subject particularly interesting. Having read the article thoroughly, I would like to recommend it for publication in Sustainability Journal. As far as the text itself is concerned, well written in terms of both its science and the editorial side.
Response 1: The authors all appreciate the reviewer’s careful review very much.
Point 2: In a few fragments, there will be a problem with the uniform text format - the spacing between the lines is different.
Response 1: We carefully checked the text format of the manuscript and re-adjusted the line spacing of the full text to make the format consistent.
Point 3: The critical remark I have, though it shall by no means deteriorate the value of the article, is that the all figures and the fonts used in the figures should be corrected, because the fonts on the figures are too small. Moreover, all figures should be presented with larger resolution - they are currently very blurred.
Response 3: According to the reviewer’s suggestions, we provided high-resolution figures and adjusted the font size in the figures in our revised manuscript.
Reviewer 2 Report
Biochar is considered as a promising biomass-based adsorbent. Investigation of the applicability of different kind of biomass for biochar/adsorbent preparation can provide interesting and useful information for the readers. H2S removal efficiency is an important parameter for adsorbent used in biogas purification technologies. The manuscript is generally well written with a logic structure. Introduction section summarizes well the stat-of-art in the field of pyrolysis and biogas desulfurization; research motivations are well defined. Applied methods are novel and adequate to the main aims of the research. Materials and methods are described clear and in details. Manuscript contains interesting and significant results that are discussed with relevant references. Experimental results are valuable not just for the science but also for practice.
Comments, suggestions:
In Abstract line 16-17 authors mention that ’other characterization methods were used to study the microscopic morphologies and physicochemical properties of unactivated and activated biochar materials’. I suggest the authors to give the applied methods, instead of general terms of ’other’ methods.
In Table 1 the standard deviations are nor given for all parameters. I suggest to give them.
If are available, please give the standard deviations for data presented in table 2-3, as well.
I suggest tha authors to give more details on the desorption and reusability of the novel adsorbents.
Author Response
Response to Reviewer 2 Comments
Point 1:The manuscript is generally well written with a logic structure. Introduction section summarizes well the stat-of-art in the field of pyrolysis and biogas desulfurization; research motivations are well defined. Applied methods are novel and adequate to the main aims of the research. Materials and methods are described clear and in details. Manuscript contains interesting and significant results that are discussed with relevant references. Experimental results are valuable not just for the science but also for practice.
Response 1: The authors appreciate reviewer #2 for the constructive suggestions to improve this manuscript.
Point 2: In Abstract line 16-17 authors mention that ‘other characterization methods were used to study the microscopic morphologies and physicochemical properties of unactivated and activated biochar materials’. I suggest the authors to give the applied methods, instead of general terms of ’other’ methods.
Response 2: According to the Reviewer’s suggestion, “other characterization methods” in the Abstract was corrected as “Fourier transform infrared spectroscopy, adsorption-desorption isotherms and pore size distributions”, a sentence was further deleted to keep the Abstract within 200 words.
Revised Text:
Abstract: ......Characterization technologies such as scanning electron microscopy, Fourier transform infrared spectroscopy, adsorption-desorption isotherms and pore size distributions and other characterization methods were used to study the microscopic morphologies and physicochemical properties of unactivated and activated biochar materials. ...... Its best performance was 38.73 mg H2S/g after 1 h of activation at 750 °C. With green synthetic processes, the inexpensive CD biochar has the potential to be used for desulfurization.
Point 3: In Table 1 the standard deviations are nor given for all parameters. I suggest to give them. If are available, please give the standard deviations for data presented in table 2-3, as well.
Response 3: In elemental analysis, the livestock manure samples were were ground properly and sieved through a 100 mesh sieve to ensure uniformity, so they were tested only once and no standard deviation were provided in our manuscript. As for Tables 2 and 3, the particles of (activated) biochar samples are very fine and have good uniformity, so they were tested only once in this study.
Point 4: I suggest the authors to give more details on the desorption and reusability of the novel adsorbents.
Response 4: Thanks to the reviewer’s suggestions, this study in our manuscript focused on testing the H2S removal performance of livestock manure biochar and its relationship with structure. Therefore, we did not carry out the test of desorption and reusability. Our follow-up research will carry out further experiment in this regard.
Reviewer 3 Report
I really enjoyed reading this manuscript – it is very well organized in perfect English. Research has great practical application. The methodology and discussion of the results are described in detail. The article must certainly be published in the journal "Sustainability" after possible minor corrections.
1.Livestock manure should be sampled in different climatic zones (or, at different sites of the specified province) or on farms with diverse livestock and provide a small table comparing the results.
- Small editing -lines 92, 99 – add “the rate of” before 20 °C
I repeat, in general, this is a very nice article, where new data is presented. The article attracts the interest of experts in the field of environmental chemistry.
Author Response
Response to Reviewer 3 Comments
Point 1: I really enjoyed reading this manuscript – it is very well organized in perfect English. Research has great practical application. The methodology and discussion of the results are described in detail. The article must certainly be published in the journal "Sustainability" after possible minor corrections.
Response 1: The authors sincerely appreciate the reviewer’s comments.
Point 2: Livestock manure should be sampled in different climatic zones (or, at different sites of the specified province) or on farms with diverse livestock and provide a small table comparing the results.
Response 2: As the reviewer pointed out, livestock manure from different climatic zones would have different physical and chemical properties, and will affect the properties of biochar and hydrogen sulfide adsorption performance. In this study, various types of livestock manure were obtained from Jiangsu Province, one of the major agricultural provinces of China. Due to China's vast territory, it is difficult for us to collect different kinds of livestock manure from different climatic zones. Therefore, this study focused to compare the H2S removal performance of different livestock manure biochar and its relationship with structure.
Point 3: Small editing -lines 92, 99 – add “the rate of” before 20 °C.
Response 3: “the rate of” was added before “20 °C” according to the Reviewer’s suggestion.
