Falling-Film Stripper for Carbamate Decomposition

摘要

A stripper (SN) for carbamate decomposition and ammonia plus carbon dioxide recovery from a urea solution (U) is realized with a shell-and-tube heat exchanger, where a liquid falling film of urea solution and a counter-current gaseous flow of a stripping medium fed to a bundle of surface-heated tubes (6); the stripping medium such as carbon dioxide is distributed into the tubes (6) by a plurality of gas risers (32); the gas risers are preferably associated to a perforated tray (30) in the bottom chamber (11) of the stripper. Revamping of a conventional CO2 stripper is also disclosed.