Distaff thistle oil: A possible new non-edible feedstock for bioenergy

The present work examines the production of biodiesel from distaff thistle (Carthamus lanatus L.) using alkali catalyzed transesterification. The low acid value (0.14 mg KOH/g) and free fatty acid (FFA) contents (2.81%) of distaff thistle oil (DTO) determined prior to transesterification indicated that the pretreatment of raw oil with acid is not required for biodiesel synthesis. The optimum operating reaction conditions of methanol to oil molar ratio (5:1), catalyst concentration (0.64%) and temperature (60°C) were applied during the transesterification to obtain the highest biodiesel yield of 97%. We have determined various fuel properties of distaff thistle oil biodiesel (DTOB) including kinematic viscosity (5.85@ 40°C c St), acid value (0.14 mg KOH/g), density (0.8980@40°C Kg/L), cetane number (50), flash point (126°C), cloud point (10°C), pour point (15°C) and distillation characteristics (358 @ 90% recovery °C). The values of fuel properties were found to be comparable with mineral diesel and in agreements with ASTM biodiesel standards. In addition to this, the synthesized fatty acid methyl esters (FAMEs) were confirmed and characterized by Gas chromatography-Mass spectroscopy (GC-MS), Fourier transform-Infra red (FT-IR), 1H NMR (Nuclear magnetic resonance) and 13C NMR analyses. Our results conclude that DTO appears to be an acceptable new non-edible oil feedstock for biodiesel industry.