Conditions Optimization and Physiochemical Analysis of Oil Obtained by Catalytic Pyrolysis of Scrap Tube Rubber Using MgO as Catalyst

Round 1

Reviewer 1 Report

In general the revised version of the manuscript contains answers of the reviewers' comments. In my opinion, the corrected manuscript is suitable for publication in its current form. I have no comments.

Reviewer 2 Report

The reviewers have satisfactorily ammended the paper in accordance with the suggestions of the reviewers. I do recommend that the paper is published.

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

Please find my comments below:

• First of all, the experimental part should include a description of the chemical and physical tests performed - the way the tests were performer, reagents and apparatus used in the prosses.
• Secondly, why did the authors stop at testing with 2 g MgO? Why didn't they do tests for larger amounts of oxide?
• Introduction should be improved. In its present form it is more like a summary.
• Why are test names or e.g. "Chemical tests" written in capital letters? After all, they are not unique names.
• Statistical values should be added to the charts.
• Besides, there are many punctuation and stylistic errors in the manuscript. The manuscript should be reviewed by a native-speaker.

Reviewer 2 Report

The subject of the paper clearly falls within the scope of this Journal.

The paper is very interesting, well written and well organized, and represents some advancement over the actual state-of-the-art. The ways and means are well described as well as the obtained results which are thoroughly discussed and conclusions are well drawn. The paper is also supported by some literature review. However, in order to make for a stronger paper, I suggest that the authors should cite and discuss the following relevant paper, which could provide useful information regarding the present study:

Gomes et al., “Toxicological Assessment of Coated versus Uncoated Rubber Granulates Obtained from Used Tires Aiming to its Use in Sport Facilities”, Journal of Air and Waste Management Association, 60(6), 741-746 (2010) - DOI: 10.3155/1047-3289.60.2.1

 I do recommend the publication of this paper, subjected to these changes.

Reviewer 3 Report

Some elements were omitted in the submitted work and require clarification. In order to be suitable for the publication in Catalysts, I would suggest major revision.

Poorly described experimental part - how was the content of the compounds determined and how were the physical parameters of the oils determined?

Lines 191-200 - this part of the work is not clear. What do these temperature ranges mean? For example: “The distillation data 193 from 20 – 100°C is also in the range of kerosene distillate (165 – 230°C) and 40% of distillate is in the range of aromatic kerosene (200 – 265°C).” or: “30% of oil fraction in the range of 158 – 200°C”

Line 189 – the authors mention two different oil fractions: By using MgO as catalyst two types of fractions i.e. Light oil and Heavy oil fractions were  obtained, which were analyzed physically shown in table 4; " Which type of oil did previous research refer to? To both together? Please clear.

Others:

Line 18 – please change sentence „…can be used as source of energy and valuable.” For example on: “ can be used as valuable source of energy”

Line 35 – what does low temperature mean, compared to what is low? „prepared at low temperature (100 oC)” 100 degrees is not low temperature.

Line 46 – please correct the punctuation „polymerization. [1, 2]” Line 47 – „Lin et al;” Line 175 „… inner tube [1][2]”

Line 79 – change to lowercase “…such as Limonene, aromatic Benzene”.

Lines 89 – 92 please focus on the description of the recycling process itself as for the other articles referenced „D. Czajczynska and co-workers [15] reviewed wasted tires dumps as habitats for mosquitos and 90 rodents that are associated with many diseases,”

Line 116 – please indicate whether any works with the use of MgO have already been published and what were their results, if not, please indicate it in the introduction.

Line 155 – “with heating rate of 5°C min−1 for 2”? Unfinished sentence? What does "2" mean?????