July 24, 2012

Japan clears Sumitomo Chemical Company's patent

The VerticalNews journalists reported that a patent by Sumitomo Chemical Company's inventors filed on November 6, 2009 was cleared and issued on July 10, 2012.

The assignee for this patent, patent number 8217197, is Sumitomo Chemical Company, Limited (Tokyo, JP).

"This application was filed claiming Paris Convention priority of Japanese Patent Application No. 2008-287060, the entire content of which is herein incorporated by reference, " quoting  Sumitomo's background information on the patent.

"The present invention relates to a process for producing methionine by a hydrolysis reaction of 5-[(2-(methylthio) ethyl)] imidazolidine-2,4-dione [refer to the following reaction formula (1)]. Methionine is useful as an additive to feeds for animals."

VerticalNews editors also obtained the inventors' summary information for this patent, "An object of the present invention is to provide a cost-effective process for producing methionine while efficiently recovering useful components."

"The present inventors made the following trial: that is, the mother liquor obtained after the separation of the second crystals was concentrated, and then, the resulting concentrate was recycled for use in the second crystallisation step. However, the filtration rate for separation became poor, which leads to a higher production cost."

"As a result of the present inventors' further studies, it is found that the amount of methionine dipeptide in the mother liquor obtained after the separation of the second crystals gives an influence on a filtration rate of methionine: in other words, when the amount of methionine dipeptide is large, the crystallinity of methionine obtained by the crystallisation becomes poor, so that the filtration rate of methionine becomes lower. Then, based on this finding, the mother liquor obtained after the separation of the second crystals was concentrated; and then, the resulting concentrate was treated by heating to hydrolyse methionine dipeptide and convert the same into methionine; and after this step, the resulting mother liquor was recycled for use in the second crystallisation step. By doing so, it is found that the crystallinity of methionine obtained by the crystallisation was improved, so that the filtration rate of methionine was remarkably improved. The present invention is accomplished based on this finding."

"According to the present invention, the filtration rate in the second crystallization step after the recycling is improved, so that the recovery of the second crystals can be efficiently carried out, with the result that methionine can be produced advantageously in view of cost."