Process for purification of EPA (eicosapentanoic acid) ethyl ester from fish oil

Disclosed is a process for extracting and purifying EPA (Eicosapentanoic acid) ethyl ester from a crude fish oil feedstock using a combination of novel esterification and simulated moving bed (SMB) techniques. Crude fish oil diluted in non-polar solvent is esterified with an acid and then transesterified with a base. Following washing, the non-polar phase is directly passed to an SMB zone, comprising a normal phase separation with a hydrophilic stationary phase agent and a non-polar/organic polar mobile phase desorbent to provide an enhanced omega-3 product, comprising EPA. In a further embodiment, the enhanced omega-3 product is passed to a second and third SMB zones operating in reverse phase using a hydrophobic stationary phase and a polar mobile phase desorbent. The process is useful for producing high purity EPA at purities in excess of 97 wt-% which are not economically recoverable by conventional distillation methods combined with conventional SMB configurations.