Method and system for preparing high-purity ammonia

The invention discloses a preparation method and system for high-purity ammonia. According to the preparation method, a raw material, namely liquid ammonia is gasified, then high-purity water is used for absorbing ammonia gas to obtain strong ammonia water, and then the strong ammonia water is subjected to two-stage rectification to produce high-purity ammonia. The preparation method of the high-purity ammonia comprises the following steps: (1) gasification of the liquid ammonia; (2) preparation of the ammonia water; (3) dehydrating; and (4) rectifying and degassing to form high-purity ammonia water. The high-purity ammonia preparation system is used for preparing the high-purity ammonia by implementing the high-purity ammonia preparation method and comprises an absorption tower, a primary tower and a rectifying tower, wherein the absorption tower is used for preparing the ammonia water, the primary tower is used for dehydrating the strong ammonia water, and the rectifying tower is used for conducting purifyi