EP0917561B1 — Elimination of trans-unsaturated fatty acid compounds by selective adsorption with zeolites

USPTO Abstract

A novel process for the selective elimination of fatty acid compounds containing carbon-carbon double bonds in trans configuration from a substrate containing cis- and trans-isomers of said fatty acid compounds, by selective adsorption by a microporous zeolite material is disclosed. The pore size and shape of usable zeolite materials enable differentiation between cis- and trans-isomers of unsaturated fatty acid chains. The zeolite materials used have a selectivity ratio alphatrans/cis higher than 1.00; this ratio is defined based on the elution properties of cis and trans double bond containing fatty acid methylesters dissolved in n-hexane during a column chromatography experiment with the zeolite material as the stationary phase and n-hexane as the mobile phase. Besides selective adsorption of trans-unsaturated fatty acid compounds, simultaneous or subsequent total or partial hydrogenation of the double bonds in said compounds can be carried out while using the same or similar zeolite material, containing finely dispersed catalytic active metals. The majority of these catalytic active sites must be inside the pores.