Production of Propanediols through In Situ Glycerol Hydrogenolysis via Aqueous Phase Reforming: A Review
, Mohd Hizami Mohd Yusoff 1,*, Zulqarnain 1, Mohd Razealy Anuar 2, Noor Fazliani Shoparwe 3 and Mohd Fikri Ab Rahman 4
Majid Soleimani
Round 1
Reviewer 1 Report
Dear authors,
Please find below my comments/suggestions in no specific order:
1. References should be written according to journal requirements (see references 6 and 7, for example) and properly cited in the text. Please recheck this aspect throughout the entire manuscript.
2. Caption of Figure 1 missing one parentheses. Reference 6 is not cited appropriately.
3. Page 3, line 134: reference [28] is not cited appropriately.
4. Page 4, lines 146-147, no reference is provided for the following statement: “Esters and ethers can also be obtained from esterification and etherification of glycerol respectively.”
5. Page 5, line 174: Probably a typing error in the statement “but id not permitted”. Please correct.
6. Please rephrase the following statement as is not very clear its sense (page 6, line 189): Commercially, propylene glycol is via hydration of propylene oxide derived from propylene by through chlorohydrin process or the hydroperoxide process
7. Page 7, line 259: Automatic references are not set properly. Please correct.
8. Page 7, line 243: Equation 1 should be referred as equation (1). Please recheck the manuscript.
9. Page 7, line 281: It is not very clear for the readers what the authors would like to say in this statement: “but are not economical in reaction parameters”. Please rephrase.
10. In Table 1, It is not very clear what “450-600 / atm” means (see line corresponding to reference [67].
11. Please improve the quality of Figure 3.
12. Page 14, line 445: It is not clear from the statement “From the table, there is standout finding by Kunthakudee” of which table the authors are speaking about.
13. The authors are stating in the manuscript that “Despite being a minor product, glycerol hydrogenolysis to 1,3-propanediol is a popular researched technology due to its high yield and selectivity with good glycerol conversion.” Even if 1,3-propanediol is a very interesting reaction product (due to its uses) up to date it was not proposed a viable process for producing it with high yields. This information is also evidenced by the information presented in Table 3 in the present manuscript. Could you please justify this statement?
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript reports on the production of propanediols from glycerol using in-situ hydrogenolysis. It is very informative, well written and easy to follow with proper transition of the content. Some comments that need to be addressed are as below:
1)L105: due to high acidity or high alkalinity? Please check.
2)Figure 2: the quality of the chemical formula is not high enough. They need to resketched.
3)L259: Please clarify the reference.
4)L273: should ‘is’ instead of ‘are’.
5)L280: The first part od this statement is not clear: ‘Only some of these yields 1,2-propanediol such as finding by Buffoni, Pompeo [67], Iriondo, Cambra [68] and Chakinala, van Swaaij [69], but are not economical in reaction parameters, and there are no techniques that can yield 1,3-pro- panediol effectively.’
6)Table 2: Please describe the parameters or abbreviates in the caption.
7)Conclusion: A brief information on challenges and economical feasibility of the main processes for propanediols should be included.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
