Mechanism and Investment Analysis of Recycling Gasoline Solvent with Mineral Powder for Asphalt Cleaning

Round 1

Reviewer 1 Report

The research presented in the article entitled “Mechanism and Investment Analysis of Recycling Gasoline Solvent with Mineral Powder for Asphalt Cleaning” addresses to the use of an alternative variant of solvent with ecological characteristics, a mineral powder. The study analyzes this material from different points of view. The article ensures complex and useful data about an ecological material, and follows the general trend in the “battle” for cleaner environment.

The Abstract presents a clear and comprehensive statement of the study described in the paper.

The Introduction and the entire paper provide enough literature references about the article’s subject and for the analysis performing.

The materials and methods are in detail described. The results are in detail presented, clearly highlighted and discussed, and the conclusions summarize them properly.

Author Response

Point-by-point responses to the reviewer’s comments

1. The research presented in the article entitled “Mechanism and Investment Analysis of Recycling Gasoline Solvent with Mineral Powder for Asphalt Cleaning” addresses to the use of an alternative variant of solvent with ecological characteristics, a mineral powder. The study analyzes this material from different points of view. The article ensures complex and useful data about an ecological material, and follows the general trend in the “battle” for cleaner environment.

Responses: Thanks for your kind comments and positive recognition to our works.

2. The Abstract presents a clear and comprehensive statement of the study described in the paper.

Responses: Thanks for your kind comments and helpful recommendations for the manuscript.

3. The Introduction and the entire paper provide enough literature references about the article’s subject and for the analysis performing.

Responses: Thanks for your kind comments and positive recommendations for the manuscript.

4. The materials and methods are in detail described. The results are in detail presented, clearly highlighted and discussed, and the conclusions summarize them properly.

Responses: Thanks for your positive comments and careful recommendations which makes our manuscript more readable and logical.

Author Response File: Author Response.docx

Reviewer 2 Report

This article aims to explore the mechanism and investment analysis of recycling gasoline solvent with mineral powder for asphalt cleaning. The following comments are suggested:

1. Please provide the physical properties of the mineral powder used.
2. Attention should be paid to the subscript representation of some chemical formulas in the article.
3. Whether the sample designed by this research is different from the actual situation, the authors should further explain.
4. What are the environmental conditions for preparing samples? The authors should further explain.
5. Page 4, lines 134-136, "...Therefore, the similar changing regularities of three XRD spectra indicated that the addition of mineral powder did not comprise any changes regarding the crystal phase." The authors should further explain.
6. Page 9, lines 244-246, "...on the other hand, using mineral 244 powder to adsorb asphalt reduced the cost by 66% cost, and declining the energy consumption by 245 94% and 86% equivalent CO₂ emission…" Please specify its calculation formula.
7. The third point of the conclusion should be used as a suggestion.

Author Response

Point-by-point responses to the reviewer’s comments

This article aims to explore the mechanism and investment analysis of recycling gasoline solvent with mineral powder for asphalt cleaning. The following comments are suggested:

1. Please provide the physical properties of the mineral powder used.

Responses: Thanks for your kind comments. We have supplemented associated physical properties of mineral powder in revised version. Part of revised content can be seen below.

The mineral powder adopted was made of limestone with average size of 48 µm, and Table 2 showed its associated physical properties. 

Table 2 Physical properties of mineral powder

2. Attention should be paid to the subscript representation of some chemical formulas in the article.

Responses: Thanks for your helpful comments. We have looked over the manuscript carefully, and related mistakes in English expressions and standard formats have been revised. You can check it in the uploaded file.

3. Whether the sample designed by this research is different from the actual situation, the authors should further explain.

Responses: Thanks for your kind comments. In this research, 150 ml gasoline solvent has dissolved all 10 g asphalt binder. But for the actual situation in asphalt research institutions, massive waste asphalt binder would be dealt with by limited gasoline solvent. Therefore, in actual situation, the miner powder can adsorb larger amount of asphalt binder than that of in this study. The further explanation has been supplemented in revised version. Part of revisions can be seen below.

The dissolved asphalt binder did not reach the maximum solubility of gasoline in this experiment [45]. Increasing the amount of dissolved asphalt in gasoline solution, the probability for mineral and asphalt components to create contacts are also increased. The practical situation occurring in asphalt laboratory usually corresponds to supersaturated solutions as massive waste asphalt binder handled by limited gasoline solvent. Therefore, it can be stated that a higher content of dissolved asphalt could entail an adsorption ratio that is better than the one investigated (4%).

Reference: Miadonye, A. and L. Evans, The solubility of asphaltenes in different hydrocarbon liquids. Petroleum science and technology, 2010. 28(14): p. 1407-1414. https://doi.org/10.1080/10916460902936960.

4. What are the environmental conditions for preparing samples? The authors should further explain.

Responses: Thanks for your kind comments. The experimental condition of simple preparation is room temperature and normal pressure. Because in actual situation, asphalt cleaning works are also implemented under this normal experimental condition. The supplemented explanation can be seen as following:

Corresponding to the actual situation for asphalt cleaning works, all procedures for sample preparation were implemented under room temperature and normal pressure conditions.

5. Page 4, lines 134-136, "...Therefore, the similar changing regularities of three XRD spectra indicated that the addition of mineral powder did not comprise any changes regarding the crystal phase." The authors should further explain.

Responses: Thanks for your kind comments. We have strengthened the discussion toward figure 2 in revised version. Part of reversion can be seen below.

Figure 2 shows the XRD spectra for three samples: A, B and C. The obtained peak (104°) belongs to calcite Ca₆C₆O₁₈. All the specimens had the peak in correspondence of the same degree value, as well as a similar flow trend. That means the crystal phase of applied mineral powder is calcite Ca₆C₆O₁₈. Moreover, the same regularities of three XRD spectra in Figure 2 indicated that after adding in pure gasoline (sample B) and adsorbing asphalt binder from solution (sample C), the mineral powder did not comprise any changes regarding the crystal phase.

6. Page 9, lines 244-246, "...on the other hand, using mineral powder to adsorb asphalt reduced the cost by 66% cost, and declining the energy consumption by 94% and 86% equivalent CO₂emission…" Please specify its calculation formula.

Responses: Thanks for your helpful comments. The reducing percentages are calculated from the results of cost and environmental impacts, aiming to quantify the improving effects for the addition of mineral powder. We have revised the phrase and listed the reducing percentages in Table 6 as following.

Table 6 Cost and environmental impacts as cleaning 1 kg asphalt with 2 approaches

7. The third point of the conclusion should be used as a suggestion.

Responses: Thanks for your helpful comments. We have revised third conclusion as a suggestion to show the objectivity. Part revision can be seen as following.

The investigated case suggested that 71.20 CNY cost, 362.90 MJ energy consumption and 25.80 kg equivalent CO2 emission were caused as removing 1 kg asphalt binder with pure gasoline, and mineral powder can reduce the quantities by 80%, 97% and 93%, respectively. 

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

1. Fix the problems of cross references.
2. It is not clearly stated that why recycle gasoline solvents in asphalt binder.
3. Why do you use mineral powder in gasoline?
4. Figure 7, how do you change the asphalt density?
5. Have you considered the efficiency of using pure gasoline and mineral powder?
6. How do you dispose the minerals with asphalt?
7. The aim and methodology are not clear.

Reviewer 2 Report

Thank you for submitting your manuscript.  I would question your use of the word 'sustainable' in terms of gasoline use within the laboratory / workplace and would suggest you re-phrase show that the use of gasoline is not 'sustainable' within most common definitions of the word.  I also have the following specific comments (given by line / figure / table number)

14:  Rephrase the sentence.  Any use of gasoline is not sustainable based on accepted / common definitions of the word

30:  XXI should be written as 21st

41: "proposing that pay attention"... is the word 'people' missing?

45:  Confusing sentence and would benefit from rephrasing

47:  I'm unclear what 'set technicians' are.  Further explanation is required

51: "with" not "while"

64: Remove the countries you have named as most, if not all countries, use gasoline every day

Figure 3:  it is unclear what you are trying to show here, e.g. it appears to show that ZnO is 100% of sample C.  If you are trying to show Table 2 in graphical form then this needs to be revised.

147: "Successfully"

145: Zn = 0.05%, Table 2 ZnO = 0.005%.  You state that the AAS results 'agreed well' with XTF.  Is this a mistake?  More explanation is required.

169: "research" not "researches"

174: "powder's" not "powders'"

213 - 220: You are not comparing similar scenarios to base your discussion.  You take into account the extraction, crushing and grinding of limestone and applying that to remove asphalt binder.  You do not do the same for gasoline, i.e. you would need to consider extraction and refining to compare and to work out the saved energy (E).  This appears to be a critical failing of your paper.

232:  Is the use of gasoline 'eco-efficient'?  This statement must be supported by literature that demonstrates that gasoline is eco-efficient.

References: must be written in the format of the journal. Clear instructions are provided https://www.mdpi.com/journal/applsci/instructions#references

You must also sort references on lines:
90, 95, 118, 128, 130, 151, 159, 171, 181, 205, 218, 226,