METHOD FOR REMOVING AMMONIA FROM SOLUTION CONTAINING AMMONIUM SALT

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently liberating and removing ammonia from a solution containing an ammonium salt to a low concentration. SOLUTION: The method is carried out as follows. The solution containing the ammonium salt is fed to the upper part of a stripping tower so as to provide a residence time of the solution in the stripping section of the stripping tower within the range of about 10-120 s in the method for liberating and removing the ammonia from the solution containing the ammonium salt, e.g. a hydrolyzed solution prepared by hydrolyzing 5-(β-methylmercaptoethyl)hydantoin in the presence of potassium carbonate and containing the ammonium salt. Steam is fed to the vapor-phase section in the lower part of the stripping tower to carry out steam stripping of the ammonia. The method is performed by feeding the hydrolyzed solution containing the ammonium salt to the upper part of the stripping tower and steam is fed into the bottom of the stripping tower to carry out the steam stripping of the ammonia. COPYRIGHT: (C)2006,JPO&NCIPI