US 12,247,002 B2
Process and apparatus for urea production
Keigo Sasaki, Narashino (JP)
Assigned to Toyo Engineering Corporation, Tokyo (JP)
Appl. No. 17/438,915
Filed by TOYO ENGINEERING CORPORATION, Tokyo (JP)
PCT Filed Mar. 14, 2019, PCT No. PCT/JP2019/010610
§ 371(c)(1), (2) Date Sep. 13, 2021,
PCT Pub. No. WO2020/183717, PCT Pub. Date Sep. 17, 2020.
Prior Publication US 2022/0185772 A1, Jun. 16, 2022
Int. Cl. C07C 273/04 (2006.01); B01D 5/00 (2006.01); B01D 19/00 (2006.01); B01D 53/18 (2006.01); B01J 19/24 (2006.01)
CPC C07C 273/04 (2013.01) [B01D 5/0012 (2013.01); B01D 19/0068 (2013.01); B01D 53/18 (2013.01); B01J 19/2465 (2013.01); B01J 2219/00092 (2013.01); B01J 2219/00164 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A process for urea production, comprising:
a synthesis step of synthesizing urea from ammonia and carbon dioxide to generate a urea synthesis solution;
a decomposition step of, by heating the urea synthesis solution generated in the synthesis step, decomposing ammonium carbamate and separating a gaseous mixture containing ammonia and carbon dioxide from the urea synthesis solution to obtain a urea synthesis solution which is higher in urea concentration than the urea synthesis solution obtained in the synthesis step;
a condensation step of, with use of a submerged condenser including a shell and tube heat exchange structure including a U-tube, absorbing and condensing at least a part of the gaseous mixture obtained in the decomposition step in an absorption medium on a shell side, and generating steam on a tube side with use of heat generated during the condensation;
a recycling step of recycling at least a part of a liquid, said liquid being obtained from the shell side in the condensation step, to the synthesis step; and
a water supply step of supplying water to the tube side of the submerged condenser at a mass flow rate that is three times or more of a generation rate of the steam generated in the submerged condenser.