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.