Characteristics of Low-Temperature Polyvinyl Chloride Carbonization by Catalytic CuAl Layered Double Hydroxide
Round 1
Reviewer 1 Report
Liu, Zhang et al. have presented a study on the experimental parameters affecting PVC pyrolysis and carbonization. The catalyst employed for the process is CuAl Layered Double Hydroxide (CuAl-LDH) that has been already reported by the same authors elsewhere. The experimental details outlined in the paper, aiming at optimizing PVC pyrolysis and carbonization parameters, could be interesting for Processes readership, however the opinion of this referee is that the paper is not suitable for publication in the present form. The most critical issues are listed below and they have to be fully addressed before publication in any journal:
- The paper is poorly written. In several sentences the verb is missing and the grammar is somehow incoherent. These make the comprehention of the manuscript really hard to the readerships. It is mandatory that an English native speaker check the document before its resubmission. The present form is not acceptable at all.
- Table 1 is puzzling and incomplete, thus making samples composition not clear at all. Please check it carefully.
- Finally, expressing the vacuum value with a negative pressure (-0.08 MPa) is really unusual if not wrong. This point should be fixed.
Author Response
Response to Reviewer 1 Comments
Comments：Liu, Zhang et al. have presented a study on the experimental parameters affecting PVC pyrolysis and carbonization. The catalyst employed for the process is CuAl Layered Double Hydroxide (CuAl-LDH) that has been already reported by the same authors elsewhere. The experimental details outlined in the paper, aiming at optimizing PVC pyrolysis and carbonization parameters, could be interesting for Processes readership, however the opinion of this referee is that the paper is not suitable for publication in the present form.
Point 1: The paper is poorly written. In several sentences the verb is missing and the grammar is somehow incoherent. These make the comprehention of the manuscript really hard to the readerships. It is mandatory that an English native speaker check the document before its resubmission. The present form is not acceptable at all.
Response 1: Thank you for your suggestion. I am really ashamed if my poor English writing level has caused any inconvenience for your reading. I have tried my best to weigh and modify the wording of the paper again and I really hope that I have made some progress. If there is still any inappropriate wording, please do not hesitate to let me know. Thank you again for your patience and kind advice.
Point 2: Table 1 is puzzling and incomplete, thus making samples composition not clear at all. Please check it carefully.
Response 2: After carefully considering your suggestion here, I've redrawn the table 1. (For the detailed revised content, please check on page 3 of the paper which I have highlighted with the red font.)
Point 3: Finally, expressing the vacuum value with a negative pressure (-0.08 MPa) is really unusual if not wrong. This point should be fixed.
Response 3: I am sorry for not clearly stating the vacuum value. I've corrected all the vacuum value（0.08MPa）. (For the detailed revised content, please check on page 1、6、7、8、9、10 of the paper which I have highlighted with the red font.).
Author Response File: 
Author Response.docx
Reviewer 2 Report
The paper have the proper structure and the Title and Abstract reflect its content. The experimental research are well described. Some explanations, modifications and corrections proposed below would be suggested:
Q1) Each abbreviation should be explained the first time it appears in the text, not just in the abstract, e.g. LDH, VOC,….
Q2) Which sample (from Table 1.) were taken for TGA investigation (Figure 1)?
Q3) How were determined onset degradation temperature?
Q4) What is effectiveness of low temperature catalytic pyrolysis of PVC in comparison to other carbonization processes?
Q5) The same questions regarding maintain time of carbonization.
Q6) Could the authors estimate costs of presented process?
Q7) Figures 2, 3, 6, 7, 8, 9 should be enlarged for greater readability. In the current state it is difficult to assess the truthfulness of some statements, e.g. in lines 124-125: "This indicates that the CuAl-LDH can significantly 124 accelerate the degradation of PVC and reduce the pyrolysis temperature.”
Author Response
Response to Reviewer 2 Comments
Comments：The paper have the proper structure and the Title and Abstract reflect its content. The experimental research are well described.
Point 1: Each abbreviation should be explained the first time it appears in the text, not just in the abstract, e.g. LDH, VOC,…
Response 1: Thank you for your suggestion here, we have modified it. (For the detailed revised content, please check on page 2 of the paper which I have highlighted with the red font.)
Point 2: Which sample (from Table 1.) were taken for TGA investigation (Figure 1)
Response 2: I am really sorry that our unclearly expression in this section has caused such doubts. The PVC/CuAl-LDH-5% were taken for TGA investigation (Figure 1).The PVC/CuAl-LDH-4% were taken for TGA investigation (Figure 2),moreover the maximum mass loss rate temperature of PVC/CuAl-LDH-4% is 305°C (For the detailed revised content, please check on page 3、4 of the paper which I have highlighted with the red font.)
Point 3: How were determined onset degradation temperature?
Response 3: Following your comment, when the mass loss rate reaches 1%/min, there is a corresponding temperature in this mass loss rate. It is the onset degradation temperature.
Point 4: What is effectiveness of low temperature catalytic pyrolysis of PVC in comparison to other carbonization processes?
Response 4: Thank you for your suggestion. The carbonization processes of PVC are affected by many factors, the carbonization temperature is the most important interfering factor, it affects not only the morphology of carbonized product but also the yield of carbonized product in comparison to other carbonization processes. So, we aim to find the lowest carbonization temperature firstly, making the yield of carbonized product maximization.
Point 5: The same questions regarding maintain time of carbonization.
Response 5: Thank you for your suggestion. We can find the carbonization reaction time from the research of carbonization maintain time. When it is determined, we would also determine the energy consumption, especially the consumption of electricity.
Point 6: Could the authors estimate costs of presented process?
Response 6: Thank you for your suggestion. we divide the cost of process into three parts. There are the cost of main electrical equipment、the cost of materials and the labor cost. The total cost of processing 1kg of PVC is about 0.95 dollar.
Point 7: Figures 2, 3, 6, 7, 8, 9 should be enlarged for greater readability. In the current state it is difficult to assess the truthfulness of some statements, e.g. in lines 124-125: "This indicates that the CuAl-LDH can significantly 124 accelerate the degradation of PVC and reduce the pyrolysis temperature.”
Response 7: Thank you for your suggestion here. Figures 2, 3, 6, 7, 8, 9 has been enlarged. (For the detailed revised content, please check the paper which I have highlighted with the red font.)
I am really sorry that our unclearly expression in this section has caused such doubts. Here I further explain: From Figure 2(a), the maximum mass loss rate of PVC/CuAl-LDH-4% is higher than that of PVC without CuAl-LDH-4%, it can be seen that CuAl-LDH can improve the mass loss rate of PVC, so, CuAl-LDH can accelerate the degradation of PVC indirectly.From Figure 2(b), the onset degradation temperature of PVC/CuAl-LDH-4% and PVC are 241℃, 252℃.It can be seen that CuAl-LDH can reduce the onset degradation temperature of PVC. To be exact, CuAl-LDH can reduce the onset pyrolysis temperature.
Author Response File: Author Response.docx
