Comparative evaluation of grape seed and Kusum oil methyl esters as renewable fuels using alkaline catalysts

The present study focuses on the production of biodiesel through the transesterification process and investigates the physicochemical properties of grape seed and Kusum oils methyl ester. Optimization of key process parameters, including molar ratio, catalyst concentration, reaction time, and temperature, was conducted for both oils. The effects of these factors on biodiesel production and conversion efficiency were analyzed. A 3 × 3 × 3 completely randomized design asymmetrical factorial approach was used to optimize reaction conditions. A total of 54 experiments were conducted to assess the effect of various parameters on ester recovery efficiency and kinematic viscosity. For grape seed oil methyl ester, optimal conditions were determined to be 0.5 wt.% KOH catalyst, 4:1 molar ratio, a reaction temperature of 60°C, and a reaction time of 60 min, resulting in a yield of 99% grape seed oil methyl ester with a viscosity of 4.25 cSt. In contrast, the optimal conditions for Kusum oil methyl ester included an 8:1 molar ratio, 1.5 wt.% KOH catalyst, a reaction temperature of 60°C, and 60‐min reaction time, achieving 95.58% yield of Kusum oil methyl ester with a viscosity of 9.53 cSt. The results indicate that grape seed oil methyl ester is a superior choice compared to Kusum oil methyl ester in terms of biodiesel yield and kinematic viscosity. The physicochemical properties of both esters, including kinematic viscosity, density, flash and fire points, cloud and pour points, and calorific value, met the ASTM D6751 and EN 14214 standards, confirming their suitability as alternative fuels for diesel engines.