Process for separating a monoethanoid fatty acid

A process for separating a monoethanoid fatty acid from a mixture of fatty acids comprising a monoethanoid fatty acid and a diethanoid fatty acid, wherein said diethanoid fatty acid possesses a higher degree of unsaturation than said monoethanoid fatty acid, which process employs a nonionic hydrophobic insoluble crosslinked polystyrene polymer adsorbent which process comprises the steps of:

• (a) maintaining net fluid flow through a column of said adsorbent in a single direction, which column contains at least three zones having separate operational functions occurring therein and being serially interconnected with the terminal zones of said column connected to provide a continuous connection of said zones;
• (b) maintaining an adsorption zone in said column, said zone defined by the adsorbent located between a feed input stream at an upstream boundary of said zone and a raffinate output stream at a downstream boundary of said zone;
• (c) maintaining a purification zone immediately upstream from said adsorption zone, said purification zone defined by the adsorbent located between an extract output stream at an upstream boundary of said purification zone and said feed input stream at a downstream boundary of said purification zone;
• (d) maintaining a desorption zone immediately upstream from said purification zone, said desorption zone defined by the adsorbent located between a desorbent input stream at an upstream boundary of said zone and said extract output stream at a downstream boundary of said zone;
• (e) passing said feed mixture into said adsorption zone at adsorption conditions to effect the selective adsorption of said monoethanoid fatty acid having a lesser degree of unsaturation by said adsorbent in said adsorption zone and withdrawing a raffinate output stream consisting essentially of said diethanoid fatty acid having a greater degree of unsaturation from said adsorption zone;
• (f) passing a desorbent material into said desorption zone at desorption conditions to effect the displacement of said monoethanoid fatty acid from the adsorbent in said desorption zone;
• (g) withdrawing an extract output stream consisting essentially of said monoethanoid fatty acid and desorbent material from said desorption zone;
• (h) passing at least a portion of said extract output stream to a separation means and therein separating at separation conditions at least a portion of said desorbent material from said monoethanoid fatty acid;
• and,
• (i) periodically advancing through said column of adsorbent in a downstream direction with respect to fluid flow in said adsorption zone the feed input stream, raffinate output stream, desorbent input stream, and extract output stream to effect the shifting of zones through said adsorbent and the production of extract output and raffinate output streams.