Evaluation of CO2 Hydrogenation in a Modular Fixed-Bed Reactor Prototype
Round 1
Reviewer 1 Report
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Comments for author File: 
Comments.pdf
Author Response
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V/r
Heather
Author Response File: Author Response.pdf
Reviewer 2 Report
In the present work the scaling up of a Fe-Mn-K based catalyst for the CO2 hydrogenation to olefins has been studied, evaluating the synthesis of the material (in the gram and kilogram range) and their catalytic performance (in a laboratory and commercial scale reactor). Some data appear clear, like the non-reproducibility of the synthesis, and the differences in their catalytic performance, specifically in the selectivity to CO which is markedly increased in the commercial scale process. On the other hand the authors studied the recycling of the feed at different ratios (recycle feed to fresh feed), observing an increase in the CO2 conversion.
The presentation is a little disorganized. The authors should reorganize the work in a more systematic way: 1) synthesis and characterization, explaining the main issues of none reproducibility, 2) the catalytic data, and the main issues involved in the catalytic test, and 3) the recycling of reactant feed.
In addition, some points are surprising for the reader and should be explained. For instance:
When the authors study the recycling of the feed, it looks that the presence of CO accelerate the reaction. Can the authors made some comments? Is there some mechanistic effect, like competitive adsorption?. The addition of some CO in the CO2 feed, accelerating the reaction rate has already been studied and is worth to be discussed.
Before recycling the authors regenerate the catalyst. How effective is the regeneration step? Did the authors a controlled experiment ensuring reproducibility of the catalytic data after catalyst regeneration?
Why the selectivty to CO increase in the commercial process? Is there any explication?
More details in the synthesis of the catalysts is needed,
Table 1 need some explanation. What means CS/Kg, LS7g….? what is the reaction time in each entry?
I suggest to modify the manuscript accordingly including in some point explanation about the observed trends.
Author Response
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Author Response File: Author Response.pdf
