Patent ID: 6126972
Filing Date: 2000-10-03
Classification: C07C,Y10S

Abstract:
In a process for the preparation of aqueous sodium methioninate solutions having a low sodium carbonate content from the crude hydrolysis mixtures obtained in the hydrolysis of 5-(.beta.-methylmercaptoethyl)-hydantoin with from 1.1 to 6 equivalents of sodium hydroxide and/or sodium carbonate, the improvement comprising the steps of:(i) distilling off water from the crude hydrolysis mixture until the sodium methioninate content is from 60 to 90 wt. %, and(ii) separating off the resulting sodium carbonate in anhydrous form as the monohydrate and/or hydrogen carbonate containing sodium methioninate residues, at a temperature of from 90 to 140.degree. C., to obtain an aqueous sodium methioninate solution.