Production and physicochemical properties of safflower seed oil extracted using different methods and its conversion to biodiesel

Abstract

The production and physicochemical characterization of high quality biodiesel from the from safflower seed oil extracted by different extraction methods was studied. The oil extraction efficiencies of various extraction methods were compared. The hydraulic press, continuous pressing (expeller) and soxhlet extraction methods were used to extract oil from safflower seeds. The soxhlet extraction method was found to have the highest oil extraction efficiency up to 32.49%. The majority of fatty acid compositions of the safflower seed oil obtained were oleic acid (C18:1) and linoleic acid (C18:2) with 30.9% and 56.4%, respectively. In other words, it has been determined that the unsaturated fatty acids of safflower seeds oil constitutes more than 89% of total fatty acids. The synthesis of safflower seeds oil into a high quality biodiesel product was carried out by a one-step transesterification process catalyzed by an alcohol/oil molar ratio of 4.799/1 and KOH catalyst. The synthesis of biodiesel by transesterification process was confirmed by FT-IR, 1H NMR, 13C NMR spectroscopy and GC-FID chromatograms. Fatty acid methyl esters (FAME) in safflower seeds oil biodiesel were identified by GC-FID analysis. Majority of FAMEs were methyl hexadecanoate (C16:0), methyl octadecanoate (C18:0), methyl 9 octadecanoate (C18:1), methyl octadec-9-enoate (C18:1), methyl 9,12-octadecadienoate (C18:2) and methyl octadecatrienoate (C18:3). The percentage conversion of safflower seed triglycerides to the corresponding methyl esters determined by 1H NMR was calculated as 94.12%. In addition, various fuel properties of the synthesized biodiesel were determined using ASTM and EN standards and compared with relevant studies. The biodiesel product synthesized from safflower seed oil meets both ASTM-D6751 and EN-14214 standards. In conclusion, safflower seed oil is promising in terms of high productivity, quality and potential in the production of biodiesel products that can be used as a substitute for fossil-based diesel fuel.