Patent ID: 9403764
Filing Date: 2016-08-02
CPC Classification: B01D,B01J,C07C,C07D,Y02P

Claim Text:
1. A method for continuous production of a methionine salt, comprising: supplying a solution comprising 5-(2-methylmercaptoethyl)-hydantoin to a topmost plate of a reactive rectification column; conducting an alkaline hydrolysis of the 5-(2-methylmercaptoethyl)-hydantoin to obtain a methionine salt in the reactive rectification column; wherein an alkaline circulating solution is supplied to the reactive rectification column on a plate located under the topmost plate, the reactive rectification column comprises from 15 to 25 vertically stacked plates, each of the vertically stacked plates comprises an area permeable to a gas a downcomer and a weir separating the gas permeable area from the downcomer, a temperature of a gas phase at a top of the reactive-rectification column is from 160° C. to 170° C., and a basicity value of the methionine salt solution at a bottom outlet of the reactive rectification column is from 2.2 to 2.8 mol base per kg of the methionine salt solution.