The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2007
Filed:
Nov. 28, 2002
Toru Kawabe, Niigata, JP;
Toshimichi Okubo, Niigata, JP;
Tadashi Umezawa, Niigata, JP;
Masayuki Sato, Niigata, JP;
Takeomi Koga, Niigata, JP;
Toru Kawabe, Niigata, JP;
Toshimichi Okubo, Niigata, JP;
Tadashi Umezawa, Niigata, JP;
Masayuki Sato, Niigata, JP;
Takeomi Koga, Niigata, JP;
Nippon Soda Co., Ltd., Tokyo, JP;
Abstract
A process by which high-quality crystals of methionine in the form of granules or thick plates having high bulk density can be stably produced. The process for production of methionine comprises the step of hydrolyzing 5-(2-methylmercaptoethyl)hydantoin into a metal salt of methionine by the use of at least one metal compound selected from the group consisting of metal hydroxides, metal carbonates, and metal bicarbonates, the step of neutralizing the metal salt of methionine under pressurizing with carbon dioxide to crystallize methionine, the step of separating the resulting mixture into methionine and a filtrate, and the step of recycling the filtrate to the step of hydrolysis of 5-(2-methylmercaptoethyl)-hydantoin, wherein the content of methionine polymers and/or salts thereof in the aqueous solution used in the crystallization step in terms of methionine polymers is adjusted to 8 wt % or below based on the amount of methionine to be formed.