Patent ID: 6274767
Filing Date: 2001-08-14
Classification: B01J,C07C,Y02P

Abstract:
A method of revamping a pre-existing urea production plant having a first urea synthesis reactor in fluid communication with an ammonia stripping section for separating free ammonia and carbamate from an aqueous urea solution discharged from said first reactor, said method comprising the steps of:a) providing a second urea synthesis reactor of the once-through type having a higher efficiency yield than said first urea synthesis reactor;b) connecting said second urea synthesis reactor upstream of said ammonia stripping section, in a manner that permits distribution of an overall production capacity exceeding that of said pre-existing plant so as to apportion from 60 to 95% of said overall capacity to said first urea synthesis reactor and from 5 to 40% of said capacity to said second urea synthesis reactor.