Recent Progress in Low-Cost Catalysts for Pyrolysis of Plastic Waste to Fuels

Round 1

Reviewer 1 Report

The review work "Recent progress in low-cost catalyst for pyrolisis of plastic waste to fuels" carried out has multiple and current references (106), which demonstrates and justifies being an appropriate work for publishing. The authors present a topic of great current interest to the scientific community so I consider that the work should be published.
However, I think some improvements could be made. Below I present the different possibilities.
1. The introduction can be more developed and referenced. For instance, lines 57 and 58 would lack 2 different references to explain these facts.
2. Different tables are presented throughout the work, but I think they should be improved to facilitate their understanding. For example, table 1 shows abbreviations of polymers that have not been explained above (PS, HGO) and the result shown in the table is not very well understood.
3. In line 135 when talking about the beta scission, no examples are specified or given showing what and when. I consider these examples to be of great importance for improving work.
4. Line 155, it would be interesting to include a table or more values with pore size and acidity
5. Lines 169-171 need further explanation.

6. Table 2 lists pressure conditions, but there is no value. In addition, in the relationship of catalyst and plastic in some cases it is directly related while in others it is made in mass. The same type of relationship should be used in all cases to make the values comparable. Something similar happens in Table 3.
7. In line 192 we talk about volatile compounds, but we should specify what these are.
8. Other references are measured in line 198, but are not included.

9. Figure 2 gives value and weight to the review work. I think more figures of this type should be included to make easier the reading and compression of the processes.
10. Table 4 shows how relationships are expressed differently and there is some value that is not included and NA is written.
11. The conclusions speak of more sustainable technology, but they should explain what it refers to since the processes described by many of them do not seem sustainable.

Author Response

1. The introduction can be more developed and referenced. For instance, lines 57 and 58 would lack 2 different references to explain these facts

Some discussions and references have been updated, please check page 2 line 61-67

2. Different tables are presented throughout the work, but I think they should be improved to facilitate their understanding. For example, table 1 shows abbreviations of polymers that have not been explained above (PS, HGO) and the result shown in the table is not very well understood.

Some words in Table 1 have been revised, please check page 5-6

3. In line 135 when talking about the beta scission, no examples are specified or given showing what and when. I consider these examples to be of great importance for improving work.

Some discussions have been added in the section 1. Please check page 4 line 143-146 and Fig. 2

4. Line 155, it would be interesting to include a table or more values with pore size and acidity

Some discussions have been added, please check page 5 line 158-175 and Figure 3

5. Lines 169-171 need further explanation.

The discussion has been added, please check page 7 line 236-245

6. Table 2 lists pressure conditions, but there is no value. In addition, in the relationship of catalyst and plastic in some cases it is directly related while in others it is made in mass. The same type of relationship should be used in all cases to make the values comparable. Something similar happens in Table 3.

Table 2 and Table 3 have been revised, please check page 8 and 10

7. In line 192 we talk about volatile compounds, but we should specify what these are.

The specific compounds have been added, please check page 9 line 17-18

8. Other references are measured in line 198, but are not included.

The references have been updated, please check page 9 line 24-26

 

9. Figure 2 gives value and weight to the review work. I think more figures of this type should be included to make easier the reading and compression of the processes.

Another figure has been added in section 6, please check page 13

10. Table 4 shows how relationships are expressed differently and there is some value that is not included and NA is written.

The table has been revised, please check page 14

11. The conclusions speak of more sustainable technology, but they should explain what it refers to since the processes described by many of them do not seem sustainable.

The section has been revised with adding some sentences, please check page 15 line 176-183

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Although the theme of this review is sound and a hot topic, its content can be further improved.

The overall english of the manuscript should be reviewed and proffed, e.g. line 20 amin should read aim, line 25 becomes should read became, among many other errors. Line 47 is a sentence that  could not understand.

The authors claim cracking and pyrolisis to be sustainable processes, but are they? Also, the authors refer to, as in the abstract, to plastic waste, but never really talk about its nature or amounts. This inofrmation should be included so that the framing of the work is better undesrtood.

The paper is a review on the types of catalysts used to improve plastic waste conversion, but this is not clear.

 

Author Response

1. The overall english of the manuscript should be reviewed and proffed, e.g. line 20 amin should read aim, line 25 becomes should read became, among many other errors. Line 47 is a sentence that  could not understand.

Some error words have been revised, please check page 1 line 21 and 26, then page 2 line 46-51

2. The authors claim cracking and pyrolisis to be sustainable processes, but are they? Also, the authors refer to, as in the abstract, to plastic waste, but never really talk about its nature or amounts. This inofrmation should be included so that the framing of the work is better undesrtood.

Some sentences have been added, please check page 1 line 27 and page 2 line 51-53

3. The paper is a review on the types of catalysts used to improve plastic waste conversion, but this is not clear.

Some discussions have been added for improving the quality of the paper, please check page 3-4 and page 13

Author Response File: Author Response.pdf

Reviewer 3 Report

I don't have question to authors

Author Response

Thank you, the article has been proof-read by professional language service.