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US 7,119,228 B2Granted
Process for producing methionine
AssigneeDegussa AG
InventorsDieter Buss, Ron Stockfleth, Martin Körfer, Jürgen Stock, Ralf Goedecke, Hans-Joachim Hasselbach, Gundolf Hornung
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Abstract
The present invention is directed to an improved process for producing methionine in which the by-product methionyl-methionine is quickly converted to the product methionine by a hydrolysis reaction. The process is performed at high temperatures (200° C. to 280° C.) and short residence times (20 s to 200 s) and results in an improved yield of end product methionine.
Claims20
A process for producing methionine, comprising:
- a) adding at least one compound selected from the group consisting of potassium carbonate;
- potassium bicarbonate;
- and potassium hydroxide;
- to a solution containing 5-(β-methylmercaptoethyl)hydantoin to hydrolyze said 5-(β-methylmercaptoethyl)hydantoin and to thereby obtain a solution containing methionine;
- b) saturating the solution containing methionine of step a) with carbon dioxide to precipitate the methionine, and separating the precipitated methionine from a first filtrate;
- c) dividing said first filtrate into a first part and a second part, returning the first part to the reaction of step a), and transferring the second part to step (d);
- d) heating the second part of the first filtrate to a temperature above 200° C. for a period of time and at a pressure sufficient to obtain a heat-treated filtrate, saturating the heat-treated filtrate with carbon dioxide to precipitate the methionine and potassium bicarbonate, and separating the precipitated methionine and potassium bicarbonate from a second filtrate;
- and
- e) either discarding the second filtrate or returning it to the reaction of step a).
6 more elements
Dependencies are inferred from the claim text.