US 12,134,590 B2
Coupled urea melamine production with HP CO2 stripping
Rahul Patil, Maastricht (NL); Johannes Henricus Mennen, Meijel (NL); and Lambertus Wilhelmus Gevers, Merkelbeek (NL)
Assigned to Stamicarbon B.V., Sittard (NL)
Appl. No. 18/688,914
Filed by Stamicarbon B.V., Sittard (NL)
PCT Filed Nov. 22, 2023, PCT No. PCT/NL2023/050614
§ 371(c)(1), (2) Date Mar. 4, 2024,
PCT Pub. No. WO2024/112199, PCT Pub. Date May 30, 2024.
Claims priority of application No. 22208870 (EP), filed on Nov. 22, 2022.
Prior Publication US 2024/0270685 A1, Aug. 15, 2024
Int. Cl. C07C 273/12 (2006.01); B01J 3/00 (2006.01); B01J 3/02 (2006.01); C07D 251/60 (2006.01); C07D 251/62 (2006.01)
CPC C07C 273/12 (2013.01) [C07D 251/60 (2013.01)] 20 Claims
 
1. A coupled process for the production of urea and melamine, the process comprising:
producing urea in a high pressure urea synthesis section comprising a high pressure (HP) CO2 stripper yielding a stripped urea solution, wherein the HP CO2 stripper uses a first part of a gaseous CO2 feed stream as stripping agent;
producing melamine in a melamine production section thereby also releasing melamine off-gas;
supplying said melamine off-gas, optionally as condensate, directly or indirectly to the high pressure urea synthesis section;
supplying the stripped urea solution directly or indirectly via a liquid flow connection to a low pressure (LP) dissociator, yielding purified urea solution and a low pressure gas stream;
subjecting the low pressure gas stream to condensation in a low pressure (LP) carbamate condensation zone with a second part of the gaseous CO2 feed stream to form a carbamate solution.