US 11,814,340 B2
Thermal stripping urea plant and process
Wilhelmus Hubertus Geurts, Sittard (NL)
Assigned to STAMICARBON B.V., Sittard (NL)
Appl. No. 17/636,257
Filed by STAMICARBON B.V., Sittard (NL)
PCT Filed Jun. 23, 2021, PCT No. PCT/NL2021/050395
§ 371(c)(1), (2) Date Feb. 17, 2022,
PCT Pub. No. WO2021/261999, PCT Pub. Date Dec. 30, 2021.
Claims priority of application No. 20181754 (EP), filed on Jun. 23, 2020.
Prior Publication US 2022/0274916 A1, Sep. 1, 2022
Int. Cl. C07C 273/04 (2006.01); B01D 5/00 (2006.01); B01J 3/02 (2006.01); B01J 3/04 (2006.01)
CPC C07C 273/04 (2013.01) [B01D 5/0075 (2013.01); B01J 3/02 (2013.01); B01J 3/042 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A urea production process carried out in a urea production plant, the plant comprising a high pressure (HP) synthesis section and a first and a second medium pressure (MP) recovery section,
wherein the HP synthesis section comprises:
a HP reaction zone,
a HP stripper of the thermal stripping type,
a HP carbamate condenser, and
a separator;
wherein the HP stripper has an outlet for stripped urea solution connected to the first MP recovery section and an outlet for gas connected to the HP carbamate condenser,
the process comprising:
separating a reaction mixture from the reaction zone at high pressure in said separator into a first stream and a second stream, wherein the first stream and the second stream both contain a liquid phase containing urea;
supplying the first stream at least in part to the HP stripper; and
supplying the second stream at least in part to the second medium pressure recovery section,
wherein the first MP recovery section comprises:
a first MP decomposer,
a first MP carbamate condenser,
a medium pressure separation column, and
an ammonia condenser;
wherein the stripped urea solution is subjected to decomposition in said first MP decomposer to give a MP urea solution and a gas stream;
wherein the gas stream is subjected to condensation in said first MP carbamate condenser;
wherein a stream from said first MP carbamate condenser is separated in said medium pressure separation column to give MP carbamate solution and an ammonia-containing gas stream;
wherein the ammonia-containing gas stream is subjected to condensation in said ammonia condenser to give an ammonia condensate stream;
wherein the second stream is expanded from high pressure to medium pressure in a MP adiabatic flashing unit comprised in the second MP recovery section thereby obtaining a gaseous stream and a flashed MP urea solution; and
wherein the gaseous stream is supplied to the first MP carbamate condenser.