No abstract

No abstract

No abstract

SummaryThe dwindling fossil fuel resources and the environmental degradation have spurred research interest to find better renewable alternative energy sources. Biodiesel is one such viable promising alternative fuel, which can be extracted from various renewable vegetable oils. In the present study, biodiesel extracted from neem oil is characterized for engine performance and emission analysis is done at various compression ratios (CR) and fuel blends. The brake thermal efficiency (BTE) of the blend B20 is considerably higher than that of diesel at CR 18, 20, and 22. The specific fuel consumption (SFC) increases with diesel blends due to a higher calorific value of diesel in comparison with biodiesel. All the biodiesel blends had lower carbon monoxide (CO) emissions compared with diesel, which indicates better combustion due to the presence of inherent oxygen. At lower CRs, the in-cylinder temperature is lower, which in turn reduces the nitrogen oxide (NO X ) emission. The overall engine performance is optimum at CR of 18 with the NB20 fuel blend.

The most competent and operative use of renewable feedstock is super critical for the production of biodiesel which has increased attention worldwide pertaining to aquatic fern Azolla. Maximizing the biodiesel yield by optimizing the process parameters of the low-frequency ultrasonic energy-assisted transesterification process of Azolla oil is the need of the hour for minimizing the production cost of biodiesel. Response Surface Methodology (RSM) was applied using central composite rotatable design (CCRD) to find the best optimum reaction parameters for this transesterification process. The optimized reaction parameters arrived from the design of experiments were as following: methanol/Azolla oils molar ratio (A)  =  6.49 mole/mole, KOH catalyst concentration (B)  =  1.69 (weight% of oil), reactiion time (C)  =  34.74 min and reaction temperature (D)  =  38.87°C. The best higher theoretical predicted Azolla Fatty Acid Methyl Ester (FAME) yield was Y  =  99.76% which is in well coincidence with the actual yield. The extracted Azolla biodiesel was tested for various fuel properties with standard test procedures and found to be in agreement with various Biodiesel standards and the results are promising in terms of utilizing Azolla oil as an inexhaustible and potentially economical source of biodiesel.