An Exploratory Study of Direct Injection (DI) Diesel Engine Performance Using CNSL—Ethanol Biodiesel Blends with Hydrogen

Round 1

Reviewer 1 Report

a) As a general observation a noticed that the citation style is not consistent: it is either (Sukij et al., 2011) or [12]; one single style should be used.

b) The English language in not bright and should be improved; bellow are just a few examples:

- row 51: "...energy chambers in vehicles" - what is this about?

-row 80: "mixes" - maybe its mixtures?

-row 82: "fuel actuals" - what does this mean?

-row 186: "The FTIR study's vibrational examination of the particle data." - this sholud be a sentence or a subtitle?

- past tense should be used all over the paper.

c) As there are so many abbreviations, a list of them would be appropriate and they should be consistent (for example we find TCCNSL, but also TC-CNSL).

c) Introduction section

I guess that rows 86 to 98 would provide the reason why B20 was used during the experiments, but, as there is not clear explanation about the tested fuels, this is just my guess.

This section should end with the aim of the paper.

e) Materials and methods section

First of all, what fuels were used? From the title I understand that the liquid fuel was made of Diesel fuel, ethanol and CNSL; was the hydrogen mixed with the fuel or introduced through the intake port of the engine, together with the air?

Is there a difference between TC-CNSL and CNSL (Table 1 refers to both of them)? And some results regarding the B20 mixture (whatever this means) should also be presented.

Row 172: did you also test CNSO?

Row 176: is it gasoline or Diesel fuel?

Sub-section 2.3: What does the fuel cell have to do with the paper?

f) Discussion section

From all the charts I understand that B20 CNSL with different amounts of hydrogen was used; does his mean 20% CNSL and 80% Diesel fuel? If so, where is the ethanol? This not at all clear; the fuels you have used should be clearly presented.

 

Author Response

Please see the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

The introduction needs more references about the production of biodiesel from the waste shell. In Introduction, the author presented only one product: Cashew Nut Shell Oil (CNSO).

Figures 3, 4 and 5 are not presented in very good quality...

The study also does not present an estimate of the cost of the fuel, for an evaluation of the interest regarding its commercialization on the market.

From a formatting point of view, there is no uniform way of writing chemical compounds. For example, the author writes the formula of nitrogen oxides NOX, or NOx... It should be written unitarily and with a subscript (as well as for the rest of the compounds). Also, the way of writing percentages is not uniform... The author generally writes %, but also percent (line 98). It should be the same everywhere.

The Conclusions chapter should more concisely present the advantages of using the tested fuel. Also, a paragraph related to the strategy regarding its use for usage at the vehicles is necessary. Also, how the research direction will continue needs to be presented.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

rows 184-191: "Figures 5 and 6 present the Diesel engine test rig, that was equipped with all the necessary equipment and devices in order to fuel the engine and to measure fuel and intake air flow, engine torque and speed, cylinder pressure and composition and temperature of the exhaust gases."

rows 195-196: "The motor performance fluctuated between 0% load and 100% load in steps of 20% during the entire process"

rows 199-201: "The data on the pressure crank angle 199 was also recorded. The average change in the crankshaft pressure angle was measured 200 based on these values." - I guess that the author refers to the recording of the cylinder pressure-crankshaft angle charts?

row 273: "Figure 14 shows the differences regarding in-cylinder heat-release rate for the CNSL biofuel mix..."

Author Response

Dear Reviewer,

Firstly, we are thankful for the time and the constructive comments. We have considered all the review comments and accordingly executed them in the revised manuscript.

Author Response File: Author Response.docx