Urea plants are often in close proximity to an ammonia plant providing the starting materials CO2 and NH3. These components react under high pressure forming ammonium carbamate as an intermediate, which slowly decomposes into urea and water. As carbamate solutions are highly corrosive, small amounts of air are continuously added to form a passive oxide layer protecting the metal surfaces. SICK can offer solutions to monitor the passivation process as well as the emission of dust, ammonia, and water at the stack.
Following product families can be used