Design and Feasibility Analysis of Commercial Silver-Based Solvent Extraction of Omega-3 PUFA
Afish oil processing facility was designed and evaluated for the annual extraction of 2.5 ktonnes of Omega-3 polyunsaturated fatty acids from 18/12EE fish oils by liquid-liquid solvent extraction through the use of a silver-based solvent. Using experimentally derived extraction efficiencies obtained with commercial 18/12EE fish oil, a plug-flow reactor configuration is proposed to significantly reduce silver solvent inventory requirements relative to conventional batch processes, corresponding to an initial capital reduction of ~$40 million at this scale. Evaluation of the proposed facilityresulted in capital costs of $4.9 million, annual operating costs of $7.7million, and a yearly gross revenue of $21.0 million. Considering the expensive solvent used, the profitability of the proposed process is highly dependent on the amount of solvent required to fill the vessels, and on the recovery efficiency following de-complexation of the Omega-3 and silver ions. Depending on market conditions, a number of recovery methods are discussed and evaluated, with specific emphasis placed on chemical, thermal or electrolytic methods.
