ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Biodiesel production from non-edible castor and sesame oils via homogeneous transesterification: comparative physico-chemical evaluation

Surya Pattnaik, Bhavya Mathur, Anusha Desai, Atul Patel, and Pradip Chowdhury

Department of Chemical Engineering, National Institute of Technology Rourkela, Rourkela, India

E-mail: chowdhuryp@nitrkl.ac.in

Received: 18 July 2024  Accepted: 29 March 2025

Abstract:

This work reports a comparative evaluation of two locally available non-edible oil feedstocks in biodiesel production. Considering the scarcity of data, shedding light on the choice of a better feedstock between castor and sesame oils, a systematic approach was envisaged using spectroscopy. FT-IR spectra show the peak shifting for functional groups in the fingerprint regions, e.g., castor oil to COBD: 1160 to 1171 cm⁻¹ and 1102 to 1022 cm⁻¹, whereas shifting of peaks from 1169 to 1158 cm⁻¹ and 1018 to 1105 cm⁻¹ are observed for sesame oil to SOBD. Conversion of triglycerides to ester was identified by NMR. The methyl ester peak is present at 3.67 ppm (¹H NMR) and carbon peaks at 174 ppm and 51 ppm (¹³C NMR). GC-MS study shows presence of primary compounds, viz. Palmitic acid, Stearic acid, Linoleic acid, Ricinoleic acid, and Oleic acid, validating the conversion to biodiesel. The final conversion was ca. 92.89% for castor oil and 93.58% for sesame oil. The yield of FAME from castor oil was 80.97% and from sesame oil 87.08%. Higher conversion and yield for sesame over castor oil to their respective FAME are primarily due to more saturated fatty acid content in the former.

Keywords: Biodiesel; Biofuels; Fatty alcohols; Fatty acids; Oils; Olericulture; Transesterification; Homogeneous catalysis; Biodiesel; FAME; Sesame oil; Castor oil

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04047-y

Chemical Papers 79 (6) 3951–3961 (2025)