Biodiesel production and selected fuel qualities from prospective non-edible oils: Hevea brasiliensis, Madhuca longifolia, Azadirachta indica, and Gossypium hirsutum.

Biodiesel predominantly originates from edible oil. Exploring non-edible oil resources is crucial to biodiesel manufacturing's commercial viability and food security. This study examines four non-edible seed oils Hevea brasiliensis, Madhuca longifolia, Azadirachta indica, and Gossypium hirsutum as biofuel feedstocks. This study optimized reaction parameters to improve base-catalyzed transesterification, oil extraction and biodiesel synthesis. The produced esters were identified by nuclear magnetic resonance, Fourier transform infrared, and gas chromatography mass spectrometry. Elements composition was determined using inductively coupled plasma-optical emission spectrometry and elemental analyzer. The biofuel's physicochemical properties met American Society for Testing and Materials and European standards. The maximum amount of crude oil was seen in Hevea brasiliensis using the soxhlet extraction process, ranging from 52-63%. This was followed by Madhuca longifolia 38-55%, Azadirachta indica 24-33%, and Gossypium hirsutum with 19-27%. The density of the plant sources exhibited a range of 0.88-0.90 g/cm3 @ 15 °C, while the kinematic viscosity showed a range of 3.2-4.1 mm2/s. The elemental composition of biodiesel, expressed as percentages of carbon, hydrogen, nitrogen, and oxygen, varied between the ranges of 70.52-76.30, 11.25-14.02, 1.18-2.75, and 9.11-13%, respectively. Since they may be grown in infertile and unproductive settings, these non-consumable seeds are cost-effective for renewable energy. They also help solve the energy situation by boosting biodiesel production.. [ABSTRACT FROM AUTHOR]