公开(公告)号：US10604477B2

公开(公告)日：2020-03-31

申请号：US15758295

申请日：2016-08-31

Applicant: Toyo Engineering Corporation

Inventor： Keishi Sato ,  Kenji Yoshimoto ,  Haruyuki Morikawa

IPC: C07C273/04 ,  C07C273/16 ,  B01J19/00 ,  B01D3/00 ,  B01D5/00

Abstract: Provided are urea manufacturing method and apparatus, which can increase the conversion ratio into urea and to reduce the consumption of steam. The temperature of the reactor is increased by introducing the entire amount of raw material ammonia and introducing a portion of the decomposed gas from the stripper into the reactor. The raw material ammonia is preferably heated using the steam condensate generated in the purification step, and/or the steam generated by the heat of condensation of the decomposed gas and the unreacted substances in the condensation step. The heating temperature is preferably between 70 and 140° C.

公开(公告)号：US11498895B2

公开(公告)日：2022-11-15

申请号：US17260834

申请日：2019-07-02

Applicant: TOYO ENGINEERING CORPORATION

Inventor： Kenji Yoshimoto ,  Keigo Sasaki

IPC: C07C273/04 ,  B01J3/04 ,  B01J19/00 ,  C07C275/02

Abstract: There is provided a process and an apparatus for urea production in which preheating of raw material ammonia or heating in a medium-pressure decomposition step can be performed at a relatively low pressure while preventing decrease in an overall heat transfer coefficient. A process for urea production includes: a synthesis step of generating a urea synthesis solution; a high-pressure decomposition step of heating the urea synthesis solution to separate a gaseous mixture containing ammonia and carbon dioxide from the urea synthesis solution; a condensation step of condensing the gaseous mixture; a medium-low-pressure steam generation step of reducing a pressure of medium-pressure steam condensate obtained in the high-pressure decomposition step to a medium-low pressure to generate medium-low-pressure steam and medium-low-pressure steam condensate; and one or both of a medium-pressure decomposition step and an ammonia preheating step.