Ultrasonic assisted extraction of oil from argan seeds using ionic liquids as novel co‑solvent

In this study, the extraction of oil from argan seeds using ultrasonic assisted extraction was investigated using n-decane as the extraction solvent and ionic liquids as the novel co-solvents. The extraction process was assessed based on the mass ratio of solvent to seed and extraction time, alongside the exploration of different ionic liquids as co-solvents. The results showed that in the absence of ionic liquid, the optimum oil yield of 35.2% was achieved at mass ratio of solvent to seed of 6:1 at 60 °C and 30 min. The extraction process adhered to pseudo-second-order kinetic model, with a rate constant of 0.0127%⁻¹ min⁻¹. When ionic liquid 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₃mim][NTf₂]) was utilized as a co-solvent alongside n-decane, the oil yield showed an improvement ranging from 0.4 to 4.0%, even when the mass of n-decane used remained similar. However, ionic liquid alone cannot serve as a substitute for n-decane as the extraction solvent. The experimental results were also compared with COSMO-RS analysis. The study demonstrates that ionic liquids can slightly enhance the oil yield by working synergistically with n-decane to improve the dissolution of lignocelluloses present on the seeds. This, in turn, facilitates better penetration of solvent into the seed matrix and enhancing the oil extraction.