Optimising the yield of neem oil biodiesel using response surface methodology and grey wolf optimisation

Sustainable energy sources, such as biodiesel, can help address the depletion of fossil fuels and their environmental impacts. This study optimises biodiesel yield from neem (Azadirachta indica) oil through transesterification, utilising grey wolf optimisation (GWO) and response surface methodology (RSM). Input factors such as the methanol and neem oil molar ratio, reaction temperature, reaction time, and stirrer rotational speed have been chosen to influence the yield of methyl ester (biodiesel) yield. Thirty experiments have been conducted using a matrix generated by a central composite design based on RSM to develop the prediction models. GWO outperformed RSM in prediction models, showing better root mean squared error and coefficient of determination. The biodiesel yield of 97.22% has been achieved using GWO with a methanol-oil molar ratio of 6.42, at a reaction temperature of 58.36°C, a reaction time of 85 minutes, and a stirring speed of 415 rpm. The physicochemical properties and FTIR analysis of processed neem oil biodiesel are within the acceptable range. [Received: November 27, 2024; Accepted: March 3, 2025]