Impact of Chemistry–Turbulence Interaction Modeling Approach on the CFD Simulations of Entrained Flow Coal Gasification
Round 1
Reviewer 1 Report
This paper presents a study about the impact of the gas-phase combustion model accuracy on gasification simulations of several reactions with the aim to find which mechanism from those found by the authors in the literature is more suitable for reproducing the entrained flow gasification processes. To this end, the authors compared two gas phase modeling approaches, they compared different gas phase global combustion mechanisms with the detailed GRI-Mech, they carried out a CFD analysis of the gas phase combustion and turbulence and they proposed the impact of the water shift reaction on the final gas composition as an example of analysis.
In my opinion, the work is globally well designed, it presents some novelty to the current literature and it could meet the requirements to be published in Energies. However, there are some major revisions to consider previously to accept the manuscript for publication. These are, as follows:
(1) Line 20: Is the aim of the work to study the mechanisms for reproducing the entrained flow gasification process for every reaction network or a specific process?
(2) Lines 25-30: Why is important to know and characterize the reaction kinetics? Is it useful, for example, for reactor design purposes? Catalysis studies? Add some information about why your work can be interesting (it is) for the scientific community.
(3) Line 25: "treating feedstock". Not every feedstock... Please, specify.
(4) Line 69: Which is the mass flow that can be used in BYU reactor?
(5) Line 110: Why did you use this correlation? You must justify why this is better than others published in the literature.
(6) Line 112: Why did you assumed that C7 was the main component? Add some references to support your assumption.
(7) Lines 111-136, 157-177: include some references to support your sentences.
(8) Line 118: Are you saying that this model is only suitable for these reaction-type models?
(9) Line 175: Why the models based on lumps are not considered?
(10) Line 177: Why these are the best models to be considered? For example, none of the models consider the CO2-char reaction as it has been described as an important reaction step for carbon-based fuels combustion.
(11) Line 208: Figures 3, 4... don´t present the labels a, b, c...
(12) Line 267: Why do you choose the best reaction mechanism based on plug-flow reactors and now you included MHI and E-gas reactors as examples to apply your model when these reactors present a flow regime very different from the plug-flow model (thus, invalidating the reaction mechanism selected)?
(13) Line 346 and figure 13: Experiment: only one point. GRI-Mech: not applicable. How can you validate the F-R/EDM and EDC methods?
(14) Same comment than (13) for Figure 15.
(15) Conclusions: this section should be revised when considering my previous comments. Additionally, what about the reactors comparison?
Author Response
Please find the responses in the attached file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript titled "Impact of Chemistry-turbulence Interaction Modeling Approach on the CFD Simulations of Entrained Flow Coal Gasification" presents analysis of the use of different chemistry-turbulence interaction approaches in the prediction of coal gasification. Three reactors geometries were simulated in order to evaluate the models used. Overall, the study is interesting, but a few points should be improved before its publication.
[1] Please define all acronyms used (SFOR, C2SM, FG-DVC, etc)
[2] Please express the equations off all devolatilization models used, as well as the respective parameters.
[3] In Page 6, Line 190: please explain why the "GRI-Mech 3.0" was considered as reference data.
[4] Figures 3,4, 8, 9, 10, 11, 13, 15, 17: consider labeling the subplots (using a, b, c, d, etc.), inorder to improve their readability.
[5] You briefly described the grid independency tests in Page 9. Please describe how they were carried out, and provide the results that support the used meshes.
Author Response
Please find the responses in the attached file.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have improved the manuscript according with my suggestions. Therefore, I recommend to accept it in its actual form.
