Removal of ammonia in urea finishing

摘要

Disclosed is a method for the removal of ammonia from the off-gas of a finishing section of a urea production plant. The method comprises contacting the off-gas with a solid adsorbent capable of physically adsorbing ammonia, particularly activated carbon or zeolite. Thereupon the solid adsorbent having ammonia adsorbed thereon is separated from the gas and regenerated by dissolving ammonia in an extraction liquid, preferably water. After separating the water from the solid adsorbent, the latter is re-used in the process.

主权项

1. A method for the removal of ammonia from the off-gas of a finishing section of a urea production plant, comprising
(a) contacting the off-gas with a solid adsorbent capable of physically adsorbing ammonia; (b) adsorbing said ammonia from said off-gas onto said solid adsorbent; (c) separating the solid adsorbent having ammonia adsorbed thereon from the gas;wherein the adsorbent is injected into the off-gas in the form of particles and wherein either:said method further comprises regenerating the solid adsorbent by dissolving ammonia in an extraction liquid, and separating the liquid from the solid adsorbent; orwherein said solid adsorbent is also capable of physically adsorbing urea dust, and said method further comprises adsorbing said urea dust from said off-gas onto said solid adsorbent.