Abstract: The author took lemon and lemongrass oil as a biofuel. He took 10,20 and 30% blends with diesel. The author claimed the brake thermal efficiency is slightly higher than diesel. He didn't discuss smoke but mentioned NOx which is increased drastically by 26%. The abstract reveals that the most dangerous oxides of nitrogen is drastically increased what would be the suggestion of the author.

Introduction: very little not enough to identify the research gap. The author should review a few more research articles to understand the gap and rectifying that with the use of novel methods. At least the recent 20 articles should be reviewed and surveyed. The suggest biodiesel with properties, to check the gap.

Preparation of OIl: Not enough to identify the process quality. Very vague explanation. Even Trasesterfication is available numerous papers but the author not reported and followed that in his work. Figure 1 very basic.

Table 1 shows the properties, the author himself reported he has taken 3 sets of biodiesel blends but reported in table one only. I hope he is not serious about this research article. Table 2 shows a very high viscosity of 30% lemon and Lemongrass oil.

Test Procedure: very little not enough even the procedure and error analysis not reported in the article.

Results and discussion: The author only reported the experimental value, no discussion, and why such values. Not validated with previous reports. so, no valid references are given.

Figures show that the data are taken once only. data validation is not satisfactory.

Figure 6 shows that the L30 initially at no load is high than decreased what is the reason the author should explain.

The experimental results show CO and HC increased, NOx also increased, Then what could be the suggestion author going to report with this work.

Figure 9 Y axis is wrong it is not CO it should be CO2

Without combustion data the research work not completed. I request the author repeat the experiment at least a 10-time mark error reading. consolidate the results then give a report. In the present form, I would like to reject this manuscript.