Continuous process for the manufacture of methionine
AssigneeDeutsche Gold- und Silber-Scheideanstalt vormals Roessler
InventorsSven Peter Mannsfeld, Arno Pfeiffer, Herbert Tanner, Hans Wagner, Erich Liebetanz, deceased
Life of this patent
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Abstract
In a continuous process 5-(.beta.-methylmercaptoethyl)-hydantoin is subjected to hydrolysis at an elevated temperature and elevated pressure in an aqueous solution of alkali carbonate or alkali bicarbonate or a mixture of these two compounds. The ammonia and carbon dioxide which form during the hydrolysis are removed and when the hydrolysis is complete the methionine is separated by means of carbon dioxide and the mother liquor is recirculated into the process after replenishing with fresh amounts of said hydantoin.
Claims11
A continuous process for the production of methionine comprising the steps of
- 1. hydrolyzing 5-(2-methylmercaptoethyl)hydantoin in an aqueous solution of an alkali-metal carbonate or bicarbonate or mixture thereof at a superatmospheric pressure and at a temperature between 120.degree. and 220.degree. C while
- 2. removing the ammonia and carbon dioxide formed during the hydrolysis;
- 3. after completion of the hydrolsis reaction cooling the solution;
- 4. precipitating the methionine by means of carbon dioxide and separating and recovering the methionine from the remaining mother liquor;
- 5. replenishing the mother liquor containing the alkali metal carbonate or bicarbonate and residual methionine with fresh 5-(2-methylmercaptoethyl)hydantoin and then
- 6. recycling the replenished mother liquor including residual methionine for further hydrolysis and treatment as in steps 1 to 5.
Dependencies are inferred from the claim text.