Effects of CoMo/γ-Al2O3 Catalysts on Product Hydrocarbon and Phenol Distribution during Hydrodeoxygenation of Oxidized Bio-Oil in a Batch Reactor
, Hongling Pan 1,2, Xuan Zhou 1,2, Zhicai Du 1,2, Guotao Li 1,2, Juan Wu 3, Xuefeng Zhang 4 and Chunquan Zhang 5Round 1
Reviewer 1 Report
The research is interesting but there are 3 main issues to be addressed before publication:
1- Authors do not mention if the analyses were replicated, what is the error of each analysis and what was the mass balance (C, O, H and S). Was there a catalyst leaching?
2- Authors expose results, but very little discussion is provided, only results are stated with no implications and or comments, with little reference to previous results in literature.
3- Technoeconomics: even though study the economy of this process is not in the scope of the work, authors should add some considerations regarding the feasability of the process.
Other minor comments are inside the text
Comments for author File: 
Comments.pdf
Author Response
Comments from Reviewer-1
The research is interesting but there are 3 main issues to be addressed before publication:
1- Authors do not mention if the analyses were replicated, what is the error of each analysis and what was the mass balance (C, O, H and S). Was there a catalyst leaching?
Responses: Thanks for reviewer’s comments, authors agreed that it is more accurate if the analysis could be performed for three times. For this research, the ASTM standard methods were applied, and the group’s previous as well as a lot of other research results have been published using one time analysis results (Fuel, 2017, 209, 634-642; 2016, 112, 319-327; 2016, 115, 159-166). For the C, H, O elements, authors used the elemental analysis via by a CE-440 Elemental Analyzer with acetanilide as the standard (C=71.09%, H=6.71%, N=10.36%, and H=11.84%). For S element, it is possible that there was some S leaching in the liquid products. Authors did not analyze it in the current research but will do further analysis in the coming research results.
2- Authors expose results, but very little discussion is provided, only results are stated with no implications and or comments, with little reference to previous results in literature.
Responses: Thanks for reviewer’s comment. Authors have added some discussion and compared it to the peer’s research results.
3- Technoeconomic: even though study the economy of this process is not in the scope of the work, authors should add some considerations regarding the feasibility of the process.
Responses: Thanks for reviewer’s comment. Authors have added some content regarding to the technoeconomic.
4-Other minor comments are inside the text
Responses: Thanks for reviewer’s comments, authors have revised them.
Reviewer 2 Report
This paper presents an interesting study on the catalytic hydrodeoxygenation of oxidized bio-oil from pyrolysis of pine wood. The experimental methods are adequately described. This batch reactor study gives proof-of-concept results, rather than scalable yields and kinetic data for process scale-up. The paper would benefit from giving more quantitative information on conversion performance. Estimates of the extent of total deoxygenation and conversion of specific functional groups would be helpful, and more strongly support the conclusions than the qualitative analysis presented. These data should be compared to prior studies of catalytic hydrodeoxygenation of bio oils. The hydrogen conversion, given in terms of % consumption of initial hydrogen, is inadequate. Calculation of hydrogen uptake by reaction, as mol reacted /kg feed, should be presented and compared to literature results.
Author Response
Comments from Reviewer-2
1-This paper presents an interesting study on the catalytic hydrodeoxygenation of oxidized bio-oil from pyrolysis of pine wood. The experimental methods are adequately described. This batch reactor study gives proof-of-concept results, rather than scalable yields and kinetic data for process scale-up. The paper would benefit from giving more quantitative information on conversion performance. Estimates of the extent of total deoxygenation and conversion of specific functional groups would be helpful, and more strongly support the conclusions than the qualitative analysis presented.
Responses: Thanks for reviewer’s comment. Due to the use of the bio-oil rather than single model chemicals, it is very hard to explain the specific functional group conversion in this research. It could be a meaning research topic in this area in future. The extend of the total deoxygenation has been demonstrated from the yield of the organic product and the chemical distribution to a certain degree.
2-These data should be compared to prior studies of catalytic hydrodeoxygenation of bio-oils.
Responses: Thanks for reviewer’s comment. Authors have added some discussion and compared it to the peer’s research results.
3-The hydrogen conversion, given in terms of % consumption of initial hydrogen, is inadequate. Calculation of hydrogen uptake by reaction, as mol reacted /kg feed, should be presented and compared to literature results.
Responses: Thanks for reviewer’s comment. This reaction was performed in a batch reactor rather than in a continuous fixed reactor. So, the hydrogen consumption calculated as mol reacted /kg feed and the economics of this reaction have not considered in this research.
Round 2
Reviewer 1 Report
The authors apporte minimal changes and did not fully addressed the comments of the reviewers
Author Response
The research is interesting but there are 3 main issues to be addressed before publication:
1- Authors do not mention if the analyses were replicated, what is the error of each analysis and what was the mass balance (C, O, H and S). Was there a catalyst leaching?
Responses: Thanks for reviewer’s comments, authors agreed that it is more accurate if the analysis could be performed for three times. For this research, the ASTM standard methods were applied, and the group’s previous as well as a lot of other research results have been published using one time analysis results (Fuel, 2017, 209, 634-642; 2016, 112, 319-327; 2016, 115, 159-166), therefore, the data presented in this manuscript was performed for one time. For the C, H, O elements, authors used the elemental analysis via by a CE-440 Elemental Analyzer with acetanilide as the standard (C=71.09%, H=6.71%, N=10.36%, and H=11.84%), authors do not calculate the mass balance separately. For S element, it is possible that there was some S leaching in the liquid products, which has been proved that 0.00028-0.0059% in the fixed continuous reaction in the published research results (BioResources 11(2), 4415-4431). Authors did not analyze it in the current research but will do further analysis in the coming research.
2- Authors expose results, but very little discussion is provided, only results are stated with no implications and or comments, with little reference to previous results in literature.
Responses: Thanks for reviewer’s comment. Authors have added some discussion and compared it to the peer’s research results.
3- Technoeconomic: even though study the economy of this process is not in the scope of the work, authors should add some considerations regarding the feasibility of the process.
Responses: Thanks for reviewer’s comment. Authors have added some content regarding to the technoeconomic.
4-Other minor comments are inside the text
Responses: Thanks for reviewer’s comments, authors have revised part of them. Authors will edit the following parts once they understand reviewer’s questions.
Line 95-95, authors do not understand the reviewer’s question.
Lines 117, 125, 197, 231: authors do not understand the reviewer’s question about the 750 psig, 1000psi, the number of 10.27 in Table1, and the title of figure 1.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The manuscript investigated the influences of catalyst status and amount on the deoxygenation of the oxidized bio-oil, but is not related to the subject of "Processes" in the whole manuscript. Thus, I would not recommendate to publish it in the journal "Processes".
In the introduction setion, the stragies of the manuscript were not mentioned. The significance of this work is not clear.
The catalyst in the current work was directly purchased and is a common commercial catalyst; therefore, there is no novelt on the materials. The characterization of catalysts is limited, which is hard to explain how the status and amount does work on the hydrodeoxygenation of the oxidized bio-oil.
Besides, English could be improved, such as "catalysts status".
Reviewer 2 Report
See attached document
Comments for author File: Comments.pdf
