Present work is an effort of an agrowaste valorization, whereby the cantaloupe seed residue has been proposed as a potential feedstock for biodiesel production. Oil, from dried cantaloupe seeds, was extracted using n-hexane as extraction solvent in three batches. Oil content was found to be 42.8% (w/w) of seed residue. Physicochemical characteristics of oil including density (0.887 g/mL), kinematic viscosity (34.5 cSt), refractive index (1.48), free fatty acid content (0.78%), iodine value (128 g I2/100 g oil) and saponification value (220 mg NaOH/g), were determined using standard IUPAC methods. Fatty acid composition of both oil/ biodiesel was determined by GC-FID and confirmed by 1H NMR spectra of methyl esters. Ultrasonic-assisted transesterification of cantaloupe seed oil was carried out using KOH as catalyst and optimization of process parameters was done using Taguchi method. Optimized parameters included molar ratio of alcohol to oil (9:1), amount of catalyst (1% w/w of oil) and reaction time (60 min). Major fuel properties of synthesized biodiesel including cetane index, flash point, cloud point, pour point, density, kinematic viscosity, total ash and distillation range were determined according to standard ASTM methods. The values were found to be within ASTM D6751 specifications for biodiesel. On the basis of findings of this study, cantaloupe seed oil may be ranked as a viable feedstock for biodiesel production.

Taslim Akhtar, Muhammad Ilyas Tariq, Shahid Iqbal, Nargis Sultana, and Kim Ei Chan