Process for the preparation of aqueous sodium methioninate solutions and use of these solutions for the preparation of a granulate

摘要

Production of aqueous sodium methioninate (I) solution containing little sodium carbonate from the crude mixture from alkaline hydrolysis of 5-( beta -methylmercapto-ethyl)-hydantoin (II) comprises: (a) distilling water from mixture, preferably with sodium hydroxide addition, until the (I) content is 60-90 wt.%; and (b) separating the sodium carbonate precipitate at 90-140 degrees C. Production of aqueous sodium methioninate (I) solution containing little sodium carbonate from the crude mixture from the alkaline hydrolysis of 5-( beta -methylmercapto-ethyl)-hydantoin (II) with 1.1-6 equivalents of sodium hydroxide and/or carbonate comprises: (a) distilling water from the mixture, preferably with addition of more sodium hydroxide, until the (I) content is 60-90 wt.%; and (b) separating the sodium carbonate precipitate in anhydrous form or as monohydrate and/or bicarbonate, at 90-140 degrees C. An Independent claim is also included for free-running (I) granulate.