Improvement of n-Butene Yield in Dimethyl Ether-to-Olefin Reaction Using Ferrierite Zeolite Catalysts

Round 1

Reviewer 1 Report

Please address the following major revisions before the manuscript will be suitable for publication.

1. The introduction is not well written. It doesn't fully align on the title of the manuscript.

2. The authors should revise the discussion under the N2 adsorption-desorption isotherms. Why is it that hysteresis loop is observed in some catalysts and not in others.

3. What criteria was followed by the authors in choosing the various loadings of the P in P-modified zeolites

4. Lewis and Bronsted acid sites can not be confirmed with NH3 TPD only, hence the statement in page 4 lines 122-124 should be revised.

5. What is the exact role of modifying the Ferrierite zeolites with P? Because at 0 loading of P, the results are better than all other modifications

6. How did the authors arrived at the RSS, F-Ratio and Regression equations presented in Table 5?

7. The authors should add more characterizations to be able to adequately explain the properties-performance relationships of the catalysts for the DTO reaction

The authors should revise the whole manuscript for typo and grammatical errors

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In the manuscript " Improvement of n-Butene Yield in Dimethyl Ether-to-Olefin Reaction Using Ferrierite Zeolite Catalysts " Hanaoka et al. investigates various ferrierite zeolites as catalysts for the dimethyl ether (DME)-to- olefin (DTO) reaction to efficiently synthesize n-butene, such as 1-butene, trans-2-butene, and cis-2-butene using a fixed-bed flow reactor. A high n-butene yield (31.2 C- mol%) was observed, which is higher than the previously reported maximum yield (27.6 C-mol%).In general, the manuscript is well organized and clearly presented. It can be accepted after minor revision. The comments are presented as follows:

1. In introduction, there are too many introductions about 1,3 butadiene, instead of Dimethyl Ether to n-Butene. The author should present the Dimethyl Ether to n-Butene reaction.

2. In Table 1 and Table 2, P(1.4)_450, P(1.1)_550, P(1.2)_600, why not prepare more catalysts at a time, the difference in the amount may also affect the reaction result?

3. In Figure 4, the temperature of the second peak for P(12)_450 exceeds 500 ℃, please explain.

4. In Table 3, Please explain the reason for the difference of n-C4= 2 over P(0)_450, P(0)_500, P(0)_550, P(0)_600.

Author Response

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Reviewer 3 Report

Review (minor revision):

In the manuscript titled; “Improvement of n-Butene Yield in Dimethyl Ether-to-Olefin Reaction Using Ferrierite Zeolite Catalysts”, the authors examine how several properties of zeolites affect the yield on n-Butene. They modified the catalysts with differing amounts of P, while also changing the calcination temperature. In the abstract, the correlation percentage (53.7 %) should be moved to the phrase “high correlation” so as to avoid confusion. As it stands it seems as though the yield is over 53 %.

Introduction:

The introduction part is well written. Short and concise.

Results and Discussion:

The lowering of the surface area observed in BET could also be caused by amorphization of the zeolite. This would also correlate nicely with the results of the XRD.

To what do the authors attribute the increase in surface area that occurs with increasing calcination temperature?

It would be interesting to see the acidity normalized per BET surface area.

In line 141 the authors mention a 2 wt% loaded Hβ zeolite, however no additional explanation was offered for this.

The authors should provide more information on how the catalytic reactions were carried out. Was there any deactivation of the catalysts observed? At what TOS was the yield recorded? Was it the 10 min mentioned in Materials and Methods?

Materials and Methods:

The authors should describe the synthesis/modification procedure of the prepared materials more. Were the samples dried prior to calcination?

Was the volume of the liquid kept constant, did the concentration of the phosphoric acid change?

Why was the ramp changed for different samples? Why did the authors keep the heat up time constant?

Conclusion:

The conclusion part is well written. It could be somewhat expanded.

Author Response

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Author Response File: Author Response.pdf