Effects of Synthesis Gas Concentration, Composition, and Operational Time on Tubular Solid Oxide Fuel Cell Performance
and Jeongmin Ahn 1
Round 1
Reviewer 1 Report
The effects of synthesis gas concentration and composition on tubular SOFC performance and longevity is shown in this work.
This topic is very intresting because this research will can allow of development of SOFC system.
In this work the variations of system design have been investigated as well as into the impacts of environmental conditions and fuel composition/concentration on SOFC performance. In the research the analysis of the impacts of the complex reaction pathways carbon monoxide participates in when used as an SOFC fuel. It was noted that despite these complexities, performance reductions as a result of the presence of CO are low when compared to similarly dilute hydrogen as a fuel. It was noted that during measurements the sensitivity to carbon deposition resulting in performance degradation was identified. So, to avoid issues with coking and anode oxidation it us necessary to careful thermal management and fuel control. It was also noted that these issues can be resolved by re-reducing the anode and oxidizing carbon or removing carbon through the reverse disproportionation or Boudouard reaction. Despite these issues, the research shows that the next research of increase SOFC performance and longevity are necesarry.
The work is good described.
The references were well matched to the research topic.
In my opinion it is necesarry to analyze and rewrite the conclusions. It should be good to include a synthetic compact overview of the achievements of these studies in Conclusion chapter.
Author Response
- In my opinion it is necesarry to analyze and rewrite the conclusions. It should be good to include a synthetic compact overview of the achievements of these studies in Conclusion chapter.
- The conclusions have been rewritten. The conclusions now focus on overview of the work presented and achievements.
Reviewer 2 Report
This work studies the effect of H2-CO ratio and operation temperature on the performance of tubular SOFC, which was explained by both fuel cell theory and SEM/EDX characterization. In my opinion, several aspects need to be improved:
1) “model methane combustion exhaust”, the term “model” is misleading, suggest to use “simulated” instead.
2) The introduction section talks too much about the experimental details. In fact, it should be focused on previous relevant studies, and what is the novelty of this work compared with them?
3) In section-2, subtitle 2.1 is missing
4) In Figure-2, where is the parameter of temperature?
5) In Table-1, Equivalence Ratio-1.5, flow rate of CO should be 50.
6) In the results section, authors tend to refer to several figures at one time. I suggest to discuss the figures one by one to avoid such chaos.
7) The title is not appropriate. For the TSOFC longevity, only one case was studied (equivalence ratio of 1.6, temperature of 800℃).
Author Response
1) “model methane combustion exhaust”, the term “model” is misleading, suggest to use “simulated” instead.
- I agree the use of simulated is more appropriate than model. “model” has been replaced with “simulated” throughout the document.
2) The introduction section talks too much about the experimental details. In fact, it should be focused on previous relevant studies, and what is the novelty of this work compared with them?
- Clarifications have been added throughout the introduction to describe the novelty of the current research and review of previous work. The major novelty of this work, however, is the usage of dilute hydrogen baseline tests to compare against simulated methane exhaust compositions, so the emphasis and thorough explanation of the experimental details present in the introduction is intended to describe the motivation and background for these new methods.
3) In section-2, subtitle 2.1 is missing
- Numbering of subsections fixed-line 128, line 147
4) In Figure-2, where is the parameter of temperature?
- Temperature parameter removed (figure caption referenced temperature from a plot used in previous version which was then modified and had not been appropriately updated) -line 180,181
5) In Table-1, Equivalence Ratio-1.5, flow rate of CO should be 50.
- Table 1 updated
6) In the results section, authors tend to refer to several figures at one time. I suggest to discuss the figures one by one to avoid such chaos.
- Ordering of figures changed to avoid references to multiple figures at once except where absolutely necessary (such as identifying the formations present in SEM imaging with EDS)
7) The title is not appropriate. For the TSOFC longevity, only one case was studied (equivalence ratio of 1.6, temperature of 800℃).
- Title has been changed to “Effects of Synthesis Gas Concentration, Composition, and Operational Time on Tubular Solid Oxide Fuel Cell Performance.” This communicates that operational time is one of three factors examined in this study, not an entire set of tests performed with varying conditions.-lines 2,3
Round 2
Reviewer 1 Report
The comments have been taken into account.
Moreover, the Authors improved the manuscript in several additional areas, which significantly increased the substantive value of the work.
The manuscript has been revised to the appropriate extent.
Therefore, I recommend that this manuscript can be published in its current form.
Reviewer 2 Report
My previous comments are well addressed in the revised manuscript.
