Process for recovering 2-hydroxy-4-methylthiobutyric acid (MHA), MHA and its use

摘要

PCT No. PCT/EP95/02515 Sec. 371 Date Jan. 13, 1997 Sec. 102(e) Date Jan. 13, 1997 PCT Filed Jun. 28, 1995 PCT Pub. No. WO96/01809 PCT Pub. Date Jan. 25, 1996It is known to isolate MHA from a reaction mixture obtained by the addition of hydrocyanic acid (HCN) to methyl mercaptopropionic aldehyde (MMP) and the hydrolysis of the methyl mercapto propionic aldehyde cyanohydrine (MMP-CH) obtained thereby with sulphuric acid, in which the reaction mixture is brought into contact with a substantially non-water-miscible organic solvent, in order to form an extraction solution having the solvent and MHA transferred from the reaction mixture, and the MHA is obtained as an extract from this extraction solution by concentration. The simplest and most economical process of the invention concerning the processing of the reaction product which facilitates the production of a highly concentrated product with an extremely low dimer, oligomer and by-product content, is characterised in that the concentration is conducted in such a way that the remaining extract contains less than 4 wt % and preferably less than 2 wt % of water. Animal feed supplement, mixtures for supplementing animal feed, e.g. with methionine or ammonium-MHA.