# US 12,215,071 B2 · Thermal stripping urea plant and process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,071 B2 - Document ID: US12215071B2 - Status: Granted - Kind: B2 - Application number: 18/609,842 - Filed: 2024-03-19 - Published: 2024-08-22 - Granted: 2025-02-04 - Earliest claimed: 2020-06-23 - Assignees: Stamicarbon B.V. - Applicants: Stamicarbon B.V. - Inventors: Wilhelmus Hubertus Geurts - Web page: https://patentgrep.com/patent/US12215071B2 ## CPC - C07C 273/04: from carbon dioxide and ammonia - B01D 5/0075: {with heat exchanging (B01D5/0039 takes precedence)} - B01J 3/02: Feed or outlet devices therefor - B01J 3/042: {in the form of a tube} - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract The disclosure pertains to a urea production plant and process using a thermal stripper, wherein the reaction mixture is separated in two parts, wherein the first part is supplied at least in part to the thermal stripper and the second part at least in part bypasses the thermal stripper and is supplied to a medium pressure recovery section. ## Claims ### Claim 1 A urea plant comprising a high pressure synthesis section comprising a reaction zone, a thermal stripper, and a carbamate condenser, the plant further comprising a first medium pressure recovery section having an inlet connected to an outlet for stripped urea solution of said thermal stripper, wherein the high pressure synthesis section comprises a high pressure separator configured for separating a high pressure reaction mixture from the reaction zone into a first stream and a second stream, the first stream and the second stream both containing a liquid phase containing urea; and wherein the high pressure separator has a first outlet for the first stream connected to an inlet of said thermal stripper, and a second outlet for the second stream connected to a second medium pressure recovery section; wherein the first medium pressure (MP) recovery section comprises a first MP decomposer, a first MP carbamate condenser, a medium pressure separation column, and an ammonia condenser; wherein said first MP decomposer is configured for subjecting the stripped urea solution to decomposition to give a MP urea solution and a gas stream from the MP decomposer, wherein said first MP carbamate condenser is configured for subjecting the gas stream from the MP decomposer to condensation, wherein said medium pressure separation column is configured for separating a stream from said first MP carbamate condenser into a MP carbamate solution and an ammonia-containing gas stream, wherein said ammonia condenser is configured for subjecting the ammonia-containing gas stream to condensation to give an ammonia condensate stream; wherein the second MP recovery section comprises: an MP adiabatic flashing unit configured for expanding the second stream from high pressure to medium pressure in the second MP recovery section thereby obtaining a gaseous stream and a flashed MP urea solution; a second MP decomposer configured for subjecting the flashed MP urea solution to decomposition to give treated urea solution and a gas stream from the second MP decomposer; a second MP carbamate condenser, configured for subjecting the gas stream from the second MP decomposer to condensation to give carbamate solution; and a gas flow line for said gaseous stream from said MP adiabatic flashing unit to said first medium pressure (MP) recovery section. ### Claim 2 (depends on 1) The urea plant according to claim 1, wherein the second MP recovery section comprises: an MP CO2 stripper configured for subjecting the urea solution from the second MP decomposer to stripping with MP CO2 feed to give a further treated urea solution and a gas stream from the MP CO2 stripper, and a flow connection for said gas stream from the MP CO2 stripper to an inlet of said second MP carbamate condenser. ### Claim 3 A method of modifying an existing urea plant, wherein the existing urea plant is a thermal stripping type urea plant, wherein the existing plant comprises a high pressure synthesis section comprising a reaction zone, a thermal stripper, and a carbamate condenser, the existing plant further comprising a first medium pressure recovery section having an inlet connected to an outlet for stripped urea solution of said thermal stripper, the method comprising: adding a high pressure separator to the high pressure synthesis section configured for separating a high pressure reaction mixture from the reaction zone into a first stream and a second stream, the first stream and the second stream both containing a liquid phase containing urea; and adding a second medium pressure (MP) recovery section, wherein the high pressure separator has a first outlet for the first stream connected to an inlet of said thermal stripper, and a second outlet for the second stream connected to said second medium pressure recovery section, wherein the method involves adding to the existing plant the following units, as part of the second MP recovery section: an MP adiabatic flashing unit configured for expanding the second stream from high pressure to medium pressure in the second MP recovery section thereby obtaining a gaseous stream and a flashed MP urea solution; a second MP decomposer configured for subjecting the flashed MP urea solution to decomposition to give treated urea solution and a gas stream from the second MP decomposer; a second MP carbamate condenser, configured for subjecting the gas stream from the second MP decomposer, to condensation to give carbamate solution; and a gas flow line for said gaseous stream from said MP adiabatic flashing unit to said first medium pressure (MP) recovery section, and a stripper configured for subjecting the urea solution from the second MP decomposer to stripping to give a further treated urea solution and a gas stream from the stripper; and a flow connection for said gas stream from the second MP decomposer to an inlet of said second MP carbamate condenser. ### Claim 4 (depends on 3) The method of claim 3, wherein the second stream is degassed. ### Claim 5 (depends on 3) The method of claim 3, wherein the stripper is an MP CO2 stripper configured for subjecting the urea solution from the second MP decomposer to stripping with MP CO2 feed to give a further treated urea solution. ### Claim 6 (depends on 3) The method of claim 3, further involving a step of increasing the reactor volume of the high pressure synthesis section. ### Claim 7 (depends on 6) The method of claim 6, wherein the step of increasing the reactor volume of the high pressure synthesis section comprises adding an additional reactor comprising the high pressure separator.