Effectiveness of Biomass Pellet Parameters on Their Fractal Dimension
Round 1
Reviewer 1 Report
1. Authors should provide information whether the presented Fig. 1 is their elaboration or provide the reference to the literature.
2. Figure 1 would be clearer if the markings and symbols appearing there were explained in the figure caption
3. The explanation of symbols from the formula (1) and (2) in the text is much less legible than directly under the formula.
4. Authors should provide information whether the presented Fig. 2 is their elaboration or provide the reference to the literature.
5. Figure 2 would be clearer if the markings and symbols appearing there were explained in the figure caption
6. Authors should provide information whether the presented Fig. 2 is their elaboration or provide the reference to the literature.
7. In the case of Figure 3, it would look better if the Authors labeled the figures as a) and b) and in the figure caption they marked: Figure 3. Biomass pellet: a)do=6 mm, b) do=8 mm.
8. The Authors of the article should use units compatible with the SI system.
9. In the text (lines 139-140), selected in yellow in the manuscript in the “3.1. Test materials and instruments” section the Authors they present:
a) moisture content was about 11% - does this moisture content apply to the mixture of raw materials before the densification process or obtained pellets?
b) density was about 1.05-1.31 g/cm3- does this range of densities apply to the mixture of raw materials before the densification process?
If these parameters relate to granules, they are inappropriate.
10. If the Authors personally produced the pellet, they should provide other process and constraction parameters: die rotational speed, die thickness, working gap, mass flow rate of the raw material through the working system, etc. If the granulate was selected externally for testing, it should be specified by whom it was made..
11. In Figure 4, the Authors present: Figure 4. Surface roughness of the molding particle (Ra =2.05 mm). In my opinion this drawing should be included in the “4. Results and discussion” section.
12. Authors should provide information whether the presented Fig. 4 is their elaboration or provide the reference to the literature.
13. The way of recording units should be standardized throughout the article. For example, density is written in one place (line 140) as (g/cm3) and in another place (Table 1) as (g×cm-3).
14. In the case of Figure 9, it would look better if the Authors marked the figures as a), b) and c) and in the figure caption they marked: Figure 9. Circular surface morphology of f 6 mm biomass pellet: a) d=6.08 mm, D=1.820, b) d=6.84 mm, D=1.6, c) d=7.41 mm, D=1.536.
15. It would look better if the Authors marked the figures as a), b) and c) in the figure caption they marked: Figure 10. Circular surface morphology of f 8mm, biomass pellet: a) d=8.26 mm, D=1.789, b) d=8.58 mm, D=1.588, c) d=8.76 mm, D=1.476.
16. The photographs in figures 9 and 10 are too small to be legible.
17. Throughout the article, Authors should standardize (improve) the size of indices for certain symbols and units.
I also attached my other comments in the article.
Comments for author File: 
Comments.pdf
Author Response
Thanks for the helpful comments.
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
The manuscript is about effectiveness of biomass pellet parameters on their fractal dimension. The scope of this article is consistent with the requirements of the Applied Sciences Journal, but it requires major revision in accordance with the comments below:
1. The introduction is too short. Avoid linking references in Introduction as in: [9-14], [15-18]. Please combine no more than two references. Instead summarise the main contribution of each referenced paper in a separate sentence.
2. Section 2 should be a part of section 3 (Materials and Mathods).
3. Incorrect form of units in Table 1.
4. Poor quality of figures 9 and 10. They are too small.
5. Results and Discussion. Not even a single reference is cited in the Results and Discussion section. Authors are suggested to add some related recent citations to make their discussion stronger.
6. Moderate English changes are required.
Author Response
Thanks for the helpful comments.
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Accepted in the present form.
