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

Authors: Ashish Chhikara; Ashwani Kumar Dhingra; Deepak Chhabra; Sunita Dhingra; Pardeep Kumar

Addresses: Department of Mechanical Engineering, University Institute of Engineering and Technology, Maharishi Dayanand University, Rohtak-124001, Haryana, India ' Department of Mechanical Engineering, University Institute of Engineering and Technology, Maharishi Dayanand University, Rohtak-124001, Haryana, India ' Department of Mechanical Engineering, University Institute of Engineering and Technology, Maharishi Dayanand University, Rohtak-124001, Haryana, India ' Department of Computer Science Engineering, University Institute of Engineering and Technology, Maharishi Dayanand University, Rohtak-124001, Haryana, India ' Department of Mechanical Engineering, Matu Ram Institute of Engineering and Management, Rohtak-124001, Haryana, India

Abstract: 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]

Keywords: neem oil biodiesel; response surface methodology; RSM; grey wolf optimisation; GWO; transesterification.

DOI: 10.1504/IJOGCT.2026.151696

International Journal of Oil, Gas and Coal Technology, 2026 Vol.39 No.2, pp.234 - 250

Received: 14 Nov 2024
Accepted: 03 Mar 2025
Published online: 16 Feb 2026 *

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