Biodiesel Production from Waste Plant Oil over a Novel Nano-Catalyst of Li-TiO₂/Feldspar

Round 1

Reviewer 1 Report

Major revision should be carried out before the manuscript could be considered for getting a publication in Catalysts. The main questions/comments are as follows:

1.       In the part of Introduction, authors should give a clear description on the reason/purpose why they chose the Li/TiO2-based catalysts for the application in transesterification reaction. The related literatures should be cited for clarifying the related research background.

2.       The reusability of the solid catalysts is very important, please provide the related experimental results and discussion. According to a previously reported literature, Li/TiO2 is not very stable during the recycling experiment due mainly to the leaching of Li ions, and the deactivation of the Li/TiO2 catalyst could be detected caused by pore-filling with or organic moieties. In the present work, I wonder if the combination with Feldspar support could improve the stability and recyclability of the Li/TiO2-based catalysts.

3.       In some cases, the yield of biodiesel decreased somewhat with the extension of the reaction time, why?

4.       The main text of the manuscript could be shorten. Some contents related to the compositions and properties of various plant oils can be put in a document of ESI.

 

Other comments/suggestions:

1.       The English expression of the whole manuscript should be improved.

2.       Please pay attention to the usage of significant digits, the abbreviation of compounds, as well as the word of “dissolved” (Is it really dissolved in the solution)?

Author Response

1. In the part of Introduction, authors should give a clear description on the reason/purpose why they chose the Li/TiO2-based catalysts for the application in transesterification reaction. The related literatures should be cited for clarifying the related research background.

Comment: Done as suggested.

2. The reusability of the solid catalysts is very important, please provide the related experimental results and discussion. According to a previously reported literature, Li/TiO2 is not very stable during the recycling experiment due mainly to the leaching of Li ions, and the deactivation of the Li/TiO2 catalyst could be detected caused by pore-filling with or organic moieties. In the present work, I wonder if the combination with Feldspar support could improve the stability and recyclability of the Li/TiO2-based catalysts.

Comment: Yes, it is known previously that activity of Li/TiO2 decreases on reuse. However, we have found in our initial studies, that Li/TiO2 supported on feldspar can be more effectively reused. The detailed studies on Li/TiO2 supported on feldspar reusability are being carried out and will be published separately in near future.

3. In some cases, the yield of biodiesel decreased somewhat with the extension of the reaction time, why?

Comment: Transesterification reaction is the equilibrium reaction and there is always possibility of reverse reaction if reaction times are longer.

 

4. The main text of the manuscript could be shorten. Some contents related to the compositions and properties of various plant oils can be put in a document of ESI.

Comment: The main text of the manuscript is shorten as recommended by reviewer.

 

 

Other comments/suggestions:

1. The English expression of the whole manuscript should be improved.

Comment: English has been proofread carefully and improved.

 

2. Please pay attention to the usage of significant digits, the abbreviation of compounds, as well as the word of “dissolved” (Is it really dissolved in the solution)?

Comment: Done as suggested and significant digits are used.

 

Reviewer 2 Report

1. Title could be changed to " Biodiesel production from waste plant oil over novel nano-catalyst  of Li-TiO2 /Feldspar

2. You use Abbreviation without mentioning that to which word it is related or Nomenclature in introduction specifically

3. What is the novelty of this manuscript? please clearly mention it in a sentence in the end of the introdcution

4. The font during the text keeps changing in materials and method specifically

5. Please read the text carefully and improved the English scientifically

6. In results and discussion , Quality of the figures are very low please increase the quality

7. In results and discussion part, why did you use these ranges for the variables? Did you use Design of experiment using a specific software ?

8. also, You could use the optimum ratio for one the raw materials and then applied it to the rest! why did you use those variables for all of them? what is the reason that the optimum ratios for different raw materials are different? when we specify the range usually we consider the range that could be effective for a wide range of materials.

 

Author Response

1. Title could be changed to " Biodiesel production from waste plant oil over novel nano-catalyst of Li-TiO2 /Feldspar

Comments: Title has been changed as suggested.

2. You use Abbreviation without mentioning that to which word it is related or Nomenclature in introduction specifically

Comments: All abbreviations are described on first time of its use.

3. What is the novelty of this manuscript? please clearly mention it in a sentence in the end of the introduction

Comments: Done as suggested.

4. The font during the text keeps changing in materials and method specifically

Comments: A uniform font has been used now.

5. Please read the text carefully and improved the English scientifically

Comments: Done as suggested.

6. In results and discussion , Quality of the figures are very low please increase the quality

Comments: Done as suggested.

7. In results and discussion part, why did you use these ranges for the variables? Did you use Design of experiment using a specific software?

Comments: The ranges were used based on the previous studies.

8. also, You could use the optimum ratio for one the raw materials and then applied it to the rest! why did you use those variables for all of them? what is the reason that the optimum ratios for different raw materials are different? when we specify the range usually we consider the range that could be effective for a wide range of materials.

 Comments: The optimum ratios were based on the previous studies. The chemical composition for various raw materials was different that is why optimum values were different for various feedstocks. Yes, mentioned ranges could be effective for a wide range of materials.

 

 

 

Round 2

Reviewer 1 Report

The manuscript can be accepted in the present form since authors have well addressed all the questions/comments proposed by referees.