Biomass–Coal Hybrid Fuel: A Route to Net-Zero Iron Ore Sintering
Round 1
Reviewer 1 Report
Dear Authors
The manuscript submitted for review contains many incomprehensible passages. In the title, the statement zero net sintering is not understandable - but zero sintering is understandable. There is no precise explanation of what, how and why affects the sintering temperature of the ore. After thorough improvement, the manuscript can be published in Sustainability.
1. The coal -biomass hybrids ecoke (a) and ecoke - please explain. Does this have process significance.
2. What CPL Industries, Immingham stands for (abbreviations are not always legible).
3. Why or 25oC/min (line 117), not and 25oC/min. It should be clarif
4. What standard defines the methodology for determining the combustion temperature on a graph - Fig. 1. (line 118)
5. What was the difference between the materials used for the tests (PT breeze and anthracite coals).
6. Why was the chemical (elemental) composition of the materials for testing not examined?
7. What LHV values were obtained from calorimmetric tests. Whether fuels were in a dry state.
8. In Chapter 2. Materials and Metchods, it is necessary to justify why such research methods have been applied.
9. No comment why these and not other research methods were replaced in the experiment.
10. Why are the results in Table 1 approximate what is the approximation. (line 185) Table 1 with commentary should be in chapter 2. Materials and Methods because it is a materials characterization.
11. No characteristics of "secondary biomass" (line 190).
12. Heat flow requires a temperature difference (line 217) - it should be explained.
13. An interesting comment regarding the difference in the determination of the heat of combustion.
14. Chapter 3. Results should start to line 217.
15. The name "heat flow" (Fig. 2, Fig. 5) is not correct - see point 13.
16. Please explain how to understand temperature T1 in maximum combustion rate. Please define the dependence of combustion temperature on combustion rate.
17 In Chapter 3. It should be written how the obtained research results relate to zero net sintering.
18. Verify the conclusions. Refer to the impact of research results on the sintering process. Comment on the results.
Regards
Reviewer.
Author Response
"Please see the attachment."
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1) Please add objectives and the novelty of the work at the end of Introduction section.
2) How material preparation and thermal analysis parameters are decided? Is it as per the convenience or any international standard based. Please add to the manuscript.
3) Please mention the number of trials used for recording the data represented in figure 2. Also draw the ERROR BAR.
4) In page number 17, just before the Conclusion section you mentioned as “Volatile matter appears to be a key parameter for fuel switching away from high fixed carbon, low volatile matter fossil fuel. Looking at this issue for two different steelmaking processes, in a sinter plant air is rapidly drawn through the sinter bed. If volatile matter combusts within the sinter bed itself, it releases heat there and only combusted by-products leave. However, if volatile matter does not combust fast enough and leaves the sinter bed, it can cause problems in the exhaust stream. This suggests that ecoke would require further treatment to reduce the volatile matter content.” How it can be treated further? Can you suggest the future direction the work to be carried to reduce the volatile matter content to traces?
5) You also mentioned as “However, during electric arc furnace operation, carbon 415 is added to the melt to increase slag foaming and so here the volatile matter is less likely to be an issue.” If it is so and if we are knowing this well in advance then what is the necessity of involving in the present inefficient method? Please explain.
In some of the REFERENCEs (Ref No. 21, 24, 26 and 35), for page number abbreviation is written as p. whereas in other references pp exists. Also, in Reference 22, Please correct CO2 as CO2 for the Format uniformity.
Author Response
"Please see the attachment."
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear Authors
Thank you for the exhaustive discussion and corrections made in the manuscript. In this version, I recommend the article for publication.
Regards
Reviewer
