Model-Based Investigation of the Interaction of Gas-Consuming Reactions and Internal Circulation Flow within Jet Loop Reactors

Round 1

Reviewer 1 Report

In this review report, I describe my judgment of the article entitled "Interaction of Reaction and Fluid Dynamics in Jet Loop Reactors " submitted to Processes by Ferdinand Breit, Oliver Bey, and Erik Von Harbou.

At the current point, the article almost meets the quality of the Processes journal. Therefore, I suggest the article publication after minor revisions. There are a few sentences that I judge could be improved. The article clearly fits the scope of the journal and detail a mechanistic model that could have a large impact on the Jet Loop Reactor design. At the moment, I have some questions regarding some model details and limitations. However, those do not decrease the quality of the developed model.

 

Below are the general and specific remarks and comments that supported the reviewer's decision:

 

Page 3, line 71: At the moment the paragraph is confusing and hard to follow. Please consider rewriting it for clarity.

Page 3, line 77: Please consider adding a comma in the following sentence: “After the fluid dynamic consideration, the….”

Page 3, line 79: Please consider adding a comma in the following sentence: “... of, for example, feed…..”

Page 3, line 98: “The developed model …”: Please be mode precise, which model is the authors referring to it? Is the one described here or the previous one?

Page 3, lines 99-108: If you are referring to the new model here, please remove this unnecessary description. If not, please briefly detail the previous model in a shorter paragraph.

Page 3, line 118: please consider another adjective better than swift. In the reviewer's opinion, this choice of words is not ideal and sounds odd.

Page 5, line 147: What is the configuration adopted in this work? From Fig. 1 it seems that the gas is only purged.

Page 7, line 189: Could the authors please consider a different term other than “no-slip”? In my opinion, this implies that there is a velocity difference between the bubbles and the liquid phase, such as the zero-velocity at a wall. Could the authors please choose a better expression? By looking at the equations, I imagine that you are using a mixture homogeneous model where the slip between the phases is zero. What about “zero-slip condition”? 

Page 10, line 257: Is V_{L,N} = V_{L, ER}? If so, why chose two variables? Please support your choice.

Page 10, line 259: Are the authors here referring to the gas flow rate from the feed? I am asking this question because the gas flow rate is a combination of the feed and the secondary contribution of the combined momentum and species model.

Section 3.3.3: Methodo of solution: The method presented here is complex, with multiple coupled equations. From the reader's standpoint, it is not easy to get the 'whole-picture' despite the well-written and clear descriptions. The reviewer could get an overview of the model in the past paragraphs. However, I am still not sure about some details and I imagine the readers will have the same feeling. Could the authors please add a diagram/flowchart to summarize the entire solution process? If possible, please add the average or approximate run-time of every single simulation and the details of the computational environment (CPU, RAM, etc...)

Figure 3: Could the authors please discuss the model limitations when the gas holdup exceeds O(10) % values. Within this limit, the no-slip (or zero-slip, Eq. (5)) no longer holds, since at this condition complex two-phase flow patterns may exist.

Page 14, line 414: Please consider adding a comma: “....above, many....”

Page 20, line 584: This observation is a key result of the developed model. Did the authors find experiment/numerical results in the literature with the same observations? I am not asking precisely for works related to JLR, but other similar reactor designs. That would certainly assess the model's robustness. On the other side, if you find opposite evidence, you should disclose the model's limitations.

Conclusion and Outlook: While reviewing the manuscript, I was expecting to find a comparison between the present model and CFD results. Could the authors please why no attempt was made to compare global results against the works from Gao et. al (2019) or Szafran and Kmiec (2004)? 

In addition, I think that would be beneficial to address that the current model could be improved by performing dedicated simple experiments and simulations (for instance, the impact of the k reaction constant on an annular gap with different geometries). Another option would be the parametric study of JLR geometry with CFD to generate a simple hydrodynamic model to feed the current model.

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 2 Report

Interaction of reaction and fluid dynamics in jet loop reactors

Briet et.al present a computational investigation of gas consuming reactive flows in jet loop reactors. Through a comprehensive sensitivity analysis, the authors have identified operating conditions that can either enhance or eliminate flow circulation within the reactor. The accompanying scientific discussion, albeit a bit long, brings out the physical principles involved.  I recommend publication of this manuscript after addressing the following minor comments.   

 

(a)  In addition to the assumptions stated in the manuscript, it will helpful if the appropriate ranges of relavent non-dimensional numbers that correspond to the assumptions and operating conditions explored in the manuscript are detailed in the manuscript. Relavent non-dimensional numbers include Re, and the ratio of convective time scale to the reaction rate constant, the ratio of input jet dynamic pressure to hydrostatic pressure etc.

 

Minor comments:

(a)  Please crosscheck and update missing citations in the supplementary text.

(b)  Title: Consider updating the title to a more descriptive one eg. “The influence of gas consuming reactive flows on the internal circulation within jet loop reactors”

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 3 Report

Ferdinand Breit, et al. Investigated the interaction of reaction and fluid dynamics in jet loop reactors. Basically, this is a very good study supported by adequate data. I just have some suggestions before an acceptance.

 

 

The authors need to improve the discussion or the introduction about the significance of this study. 

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf