Ammonia recovery by scrubbing and condensing

摘要

This invention teaches a method and apparatus for recovering ammonia from a waste gas mixture comprising ammonia with air, and water vapor or steam. The waste gas is bubbled upwardly through an aqueous bath in a condenser, and then through a scrubber in direct contact with a spray of fresh water. The scrubber and condenser are formed integrally so that fresh ammonia water from the scrubber joins the aqueous bath in the condenser. The temperature of the aqueous bath is controlled, preferably by sensing the temperature thereof to control flow of cooling fluid in noncontact heat exchange with the aqueous bath in the condenser. Aqueous ammonia from the bath is withdrawn as product, but it is recycled to the bath if its ammonia concentration is inadequate.