METHOD FOR RECOVERING AMMONIA, METHOD FOR REUTILIZING AMMONIA, AMMONIA RECOVERY SYSTEM AND AMMONIA REUTILIZATION SYSTEM

摘要

PPROBLEM TO BE SOLVED: To provide a method for recovering ammonia where high purity ammonia is recovered from an exhaust gas exhausted from nitride semiconductor fabrication equipment in such a manner that the concentration of impurities is reduced at most to 50 ppb, to provide a method for reutilizing ammonia, to provide an ammonia recovery system, and to provide an ammonia reutilization system. PSOLUTION: The method for recovering ammonia is provided with: a stage where a reaction product of ammonia and organic metals, and organic metals are removed from an ammonia-containing exhaust gas exhausted from nitride semiconductor fabrication equipment 11, so as to obtain a gaseous mixture; a stage where crude gaseous ammonia is separated from the gaseous mixture; a stage where the crude gaseous ammonia is liquified, so as to obtain liquified crude ammonia; and a stage where the liquified crude ammonia is distilled, thus impurities are removed from the liquified crude ammonia, so as to obtain high purity ammonia. PCOPYRIGHT: (C)2008,JPO&INPIT