Process for the preparation of aqueous sodium methioninate solutions (C)

摘要

Aqueous sodium methioninate solutions which are virtually free from foreign salts are prepared by hydrolysing 5-(ss-methylmercaptoethyl)hydantoin with a mixture of 1 equivalent of sodium hydroxide and 2 equivalents of calcium oxide or calcium hydroxide, in each case based on the 5-(ss-methylmercaptoethyl)hydantoin employed, at temperatures between 110 and 180 DEG C, removing, after the hydrolysis has ended, the calcium carbonate which has precipitated and concentrating the remaining aqueous sodium methioninate solution to expel the ammonia which it contains, preferably to a sodium methioninate content of 40 to 65% by weight.