Abstract: A urea production process comprising concentrating a first urea solution in a first vacuum evaporator in an evaporation section to give a urea melt and a first vapor, and condensing the first vapor in a first condensation section, wherein the first condensation section is a chilled condensation section, and a urea production system comprising the chilled condensation section.

Abstract: An apparatus for treatment of process vapours coming from a vacuum concentration section of a urea plant, comprising a vacuum system having a plurality of successive condensation stages, connected in series by respective line portions and crossed in series by process vapours to be treated; the apparatus has at least one primary steam condensate inlet for feeding steam condensate to the vacuum system and positioned, with reference to a circulation direction of the process vapours in the vacuum system, upstream of at least one selected condensation stage, or in at least one selected condensation stage.

Abstract: Method and apparatus that enable the more efficient manufacture of urea are provided. Before unreacted substances are removed from a urea synthesis solution obtained from a stripper, the urea synthesis solution is placed under pressure reduced from the synthesis pressure. Thus, a gas-liquid mixture is obtained. The gas-liquid mixture is heated with a decomposed gas from the stripper using a shell-and-tube heat exchanger, and then introduced into a purification system. In the heating, the gas-liquid mixture is introduced into the shell of the heat exchanger while the decomposed gas is introduced into the tube side of the heat exchanger.

Abstract: Method for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section with a horizontal pool condenser, wherein the method comprises exchanging heat from a high pressure process medium received in a shell section of the pool condenser to a medium pressure urea containing solution received in a first heat exchanging section provided in the pool condenser to at least decompose ammonium carbamate into NH3 and CO2, wherein the method further comprises exchanging heat from the high pressure process medium to a low pressure steam condensate received in a second heat exchanging section provided in the pool condenser to produce low pressure steam. The invention also relates to an apparatus for the production of urea from ammonia and carbon dioxide.

Abstract: The invention relates to a method of manufacturing urea as a nitrogen-rich synthetic fertilizer from refuse of any composition, preferably from domestic waste. The organic waste components are first turned into gas in a high-temperature reactor with oxygen (O2) which has been obtained in a cryogenic air separation plant. A synthesis gas arises which predominantly comprises carbon monoxide (CO), hydrogen (H2) and carbon dioxide (CO2). The carbon monoxide (CO) contained in the synthesis gas is subsequently converted with steam into hydrogen (H2) and carbon dioxide (CO2). The hydrogen is subsequently separated and is used for ammonia synthesis together with the elementary nitrogen (N2) which arises as a by-product in cryogenic air separation. In the last process step, urea (CO(NH2)2) is manufactured from ammonia (NH3) and the further synthesis gas component carbon dioxide (CO2).

Abstract: The invention relates to a process for producing urea wherein an aqueous urea solution, leaving a urea reaction zone is fed to a stripper, where a part of the non-converted ammonia and carbon dioxide is separated from the aqueous urea solution, which solution leaves the stripper to a first recovery section of one or more serial recovery sections and is subsequently fed to one or more urea concentration sections, wherein the urea solution leaving the stripper is subjected to an adiabatic expansion, thus creating a vapor and a liquid, which are separated before the liquid enters a first recovery section and the vapor is condensed. The invention further relates to a urea plant comprising a stripper and a first recovery section, wherein an adiabatic expansion valve and a liquid/gas separator is provided between the stripper and the first recovery section.

Abstract: A modular system and method for producing urea from bio-mass includes means and steps for “homogenizing” a biomass feedstock stream having components with different bulk density BTU content into a stream having a consistent bulk density BTU content. The steps include cleaning the incoming bio-mass feedstock stream to remove non-organic matter, blending the cleaned bio-mass feedstock stream to obtain a homogeneous blend having a consistent bulk density BTU content, and milling the homogeneous blend bio-mass feedstock stream to a predetermined size no greater than 12 mm.

Abstract: The present invention is directed to the modification of the hydrocarbon production sequence of operations including the Fischer-Tropsch process for the production of hydrocarbon fuels in an efficient manner, along with the production of commercially valuable co-products from by-products of the hydrocarbon production process.

Abstract: Disclosed is a plant for the production of urea. The plant comprises conventional sections for synthesis and recovery, for evaporation and condensation, for urea finishing, and for dust scrubbing. According to the invention, an additional evaporation and condensation loop is introduced from and to the dust scrubbing section. This loop results in a more favorable energy consumption of the plant.

Abstract: The invention relates to a method for urea production and to a urea production plant wherein ammonia emission in the final step of forming urea prills is reduced. In the method, the concentration of a urea solution is performed in at least three consecutive concentration steps and the residence time of urea melt leaving a last concentrator to the prilling tower is minimized. This can be achieved by placing the last concentrator in adjacency with a urea melt inlet of the prilling tower, such as above the prilling tower. In this way, the ammonia emission in the prilling tower can be reduced by as much as 50% compared to the conventional urea production plants. The invention further relates to a method for reducing ammonia emission in the prilling tower of an existing urea production plant.

Abstract: An operation method of a urea production plant including multiple systems that can prevent a considerable decrease in urea production even when an ammonia synthesis facility is shut down. At a time of producing urea from CO2 and ammonia, in a case where urea production plants including at least two systems are arranged in parallel, when an ammonia production facility (10A) of one of the systems is shut down, liquefied ammonia stored in the shut down system is used, and a CO2 recovery amount in a CO2 recovery facility (23) in an ammonia synthesis facility (10B) of the other system is increased. Synthesis of urea can be then continued by a urea synthesis unit (30A1) in the shut down system by using the increased recovered CO2 and the liquefied ammonia.

Abstract: An integrated process for the manufacture of olefins and intermediates for the production of ammonia and urea, comprising an FCC reactor, a regenerator, a steam reforming unit, an air-separation unit, an ammonia production unit and a urea production unit, is described. This process makes it possible to minimize CO2 emissions to atmosphere, make use of heavy feedstocks of low added value (AR) for the production of light olefins, in addition to making maximum use of all the flows involved, thus increasing the energy efficiency achieved, all at the same time.

Abstract: A process for the direct synthesis of urea from ammonia and carbon dioxide at high pressures and temperatures, with the formation of ammonium carbamate as intermediate, comprising a decomposition step of the ammonium carbamate and stripping of the gases formed, operating substantially at the same pressure as the synthesis step, wherein the recycled liquid streams are fed, at least partially, to the same decomposition and stripping step after being preheated by heat exchange with a stream included in the high-pressure synthesis cycle.

Abstract: An operation method of a urea production plant including multiple systems that can prevent a considerable decrease in urea production even when an ammonia synthesis facility is shut down. At a time of producing urea from CO2 and ammonia, in a case where urea production plants including at least two systems are arranged in parallel, when an ammonia production facility (10A) of one of the systems is shut down, liquefied ammonia stored in the shut down system is used, and a CO2 recovery amount in a CO2 recovery facility (23) in an ammonia synthesis facility (10B) of the other system is increased. Synthesis of urea can be then continued by a urea synthesis unit (30A1) in the shut down system by using the increased recovered CO2 and the liquefied ammonia.

Abstract: Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising at least one reactor section, a stripper and a condenser wherein all the high-pressure equipment is placed in a low position, wherein the height of the high-pressure section is less than 35 m from ground level and at least one of the reactor sections comprises means for the separate distribution of ammonia in the bottom of the reactor section.

Abstract: The invention relates to a method for urea production and to a urea production plant wherein ammonia emission in the final step of forming urea prills is reduced. In the method, the concentration of a urea solution is performed in at least three consecutive concentration steps and the residence time of urea melt leaving a last concentrator to the prilling tower is minimised. This can be achieved by placing the last concentrator in adjacency with a urea melt inlet of the prilling tower, such as above the prilling tower. In this way, the ammonia emission in the prilling tower can be reduced by as much as 50% compared to the conventional urea production plants. The invention further relates to a method for reducing ammonia emission in the prilling tower of an existing urea production plant.

Abstract: A urea reactor tray having a base plate; and a number or quantity of hollow cup-shaped members, which project vertically from the base plate along respective substantially parallel axes perpendicular to the base plate, and have respective substantially concave inner cavities communicating with respective openings formed in the base plate; the tray having a number or quantity of first cup-shaped members, each of which extends axially between an open top end having the opening, and a closed bottom end, and has a lateral wall with through holes substantially crosswise to the axis, and a bottom wall which closes the closed bottom end and has no holes.

Abstract: Plant for urea production from ammonia and carbon dioxide having a so-called high-pressure section which comprises a synthesis reactor and a condensation unit (7, 107) positioned inside the reactor, all substantially operating at the same pressure.

Abstract: Disclosed is a process for the production of a syngas mixture by catalytic partial oxidation. The syngas mixture is suitable as an intermediate in the production of hydrogen. According to the invention, the syngas is cooled, prior to a water gas shift reaction, with liquid water. This has the advantage of avoiding the problem of metal dusting, and it presents a gas mixture comprising water vapor that is particularly suitable for a water gas shift reaction in the production of hydrogen.

Abstract: Disclosed is a method for the production of urea allowing a substantial reduction, even down to zero, of the continuous emission of ammonia conventionally resulting from such a process. According to a preferred embodiment of the invention, the urea-forming reaction from carbon dioxide and ammonia is conducted in a synthesis section that does not require passivation by oxygen. As a result of the absence of oxygen, a hydrogen-rich gas stream results from the synthesis section, that can be used as a fuel in an incinerator. In the incinerator, ammonia-comprising gas streams from the urea production process are combusted.

Abstract: A process for ammonia -urea production where: liquid ammonia produced in an ammonia section is fed to a urea section directly at the ammonia synthesis pressure, and where the liquid ammonia is purified at high pressure with the steps of: cooling the liquid ammonia (20) obtaining a cooled liquid ammonia stream (21), separating a gaseous fraction (22) comprising hydrogen and nitrogen from said cooled liquid ammonia, obtaining purified liquid ammonia (23) at a high pressure, and reheating said purified liquid ammonia (23) after separation of said gaseous fraction, obtaining a reheated purified ammonia (24) having a temperature suitable for feeding to the urea synthesis process. The application also deals with an ammonia -urea plant comprising an ammonia cooler, a liquid-gas separator and an ammonia re-heater and with a method for revamping existing ammonia -urea plants.

Abstract: A modular system and method for producing urea from bio-mass includes cleaning a bio-mass feedstock to remove substantially all non-organic matter; blending the cleaned bio-mass to obtain a substantially homogeneous blend; pelletizing the blended bio-mass; and gasifying the pellets in a gasifier. The bio-mass feedstock may include bio-mass materials having different processing characteristics. The gasifying step preferably includes pulverizing the pellets to a fine particle size, injecting an organic oil into the input biomass mist when needed, and controlling the feed rate to maintain a substantially constant burn temperature. The resultant syngas stream is cleaned and compressed to a high pressure of about 6,000 to 7,000 psi. The resultant ammonia stream is processed in a bypass recycling loop system at 30% conversion rate at a high pressure of about 6,000 to 7,000 psi.

Abstract: A method and apparatus is provided for cleaning flue gases from combustion plants. The method includes removing dust and removing nitrogen from flue gases, bringing flue gases into contact with an aqueous ammonia solution in the presence of an oxidizing agent whereby a reaction solution forms which contains at least ammonium carbonate, heating the reaction solution such that ammonium carbonate decomposes and carbon dioxide and ammonia transfer into the gas atmosphere, and reacting the gaseous carbon dioxide and the gaseous ammonia to form urea. The apparatus includes a device for removing nitrogen and removing dust from the flue gases, a washing device downstream of the device for removing nitrogen and removing dust, a stripper downstream of the washing device, and a urea installation downstream of the stripper.

Abstract: A process for urea production from ammonia and carbon dioxide, made to react at a predetermined high pressure in an appropriate synthesis reactor (112), from the reaction between NH3 and CO2 being obtained a reaction mixture comprising urea, ammonium carbamate and free ammonia in aqueous solution, from which a recovery of ammonium carbamate and ammonia is carried out with their subsequent recycle to the synthesis reactor (112), said recovery from the reaction mixture taking place through operative steps of decomposition of the ammonium carbamate into NH3 and CO2 and of their stripping and a subsequent operative step of their recondensation into ammonium carbamate that is recycled to the synthesis reactor, the said reaction mixture obtained from the reaction between ammonia and carbon dioxide being pumped to the operative steps of decomposition and stripping.

Abstract: Process for increasing the capacity of an existing urea plant comprising a high-pressure urea synthesis section and one or more recovery sections, wherein next to the existing urea plant a urea production unit, comprising a high-pressure urea synthesis section and a medium-pressure recovery section, is installed, wherein a urea-containing stream is produced from ammonia and carbon dioxide and the urea-containing stream is sent to the existing urea plant where the urea-containing stream is further purified in the low-pressure recovery section.

Abstract: A process for producing urea is disclosed, wherein liquid ammonia and carbon dioxide are reacted in a high-pressure synthesis section (100), and at least part of the carbon dioxide is fed to said synthesis section (100) in liquid phase. A plant operating according to said process and a method for modernizing existing plants accordingly are also disclosed.

Abstract: Disclosed is a method for the removal of ammonia from the off-gas of a finishing section of a urea production plant. The method comprises contacting the off-gas with a solid adsorbent capable of physically adsorbing ammonia, particularly activated carbon or zeolite. Thereupon the solid adsorbent having ammonia adsorbed thereon is separated from the gas and regenerated by dissolving ammonia in an extraction liquid, preferably water. After separating the water from the solid adsorbent, the latter is re-used in the process.

Abstract: The invention relates to a process for producing urea wherein an aqueous urea solution, leaving a urea reaction zone is fed to a stripper, where a part of the non-converted ammonia and carbon dioxide is separated from the aqueous urea solution, which solution leaves the stripper to a first recovery section of one or more serial recovery sections and is subsequently fed to one or more urea concentration sections, wherein the urea solution leaving the stripper is subjected to an adiabatic expansion, thus creating a vapor and a liquid, which are separated before the liquid enters a first recovery section and the vapor is condensed. The invention further relates to a urea plant comprising a stripper and a first recovery section, wherein an adiabatic expansion valve and a liquid/gas separator is provided between the stripper and the first recovery section.

Abstract: Process for the preparation of urea from ammonia and carbon dioxide in a urea production process comprising, in a high-pressure synthesis section: a. a reactor, wherein ammonia and carbon dioxide react to form a urea-comprising synthesis solution; b. a stripper, wherein the urea-comprising synthesis solution is heated and stripped, optionally in counter-current with a stripping agent; c. a submerged condenser, wherein the gas leaving the top of the stripper is, at least partially, condensed to form a condensate solution and d. an ejector, in the line connecting the submerged condenser and the reactor, supporting the transport of the condensate solution from the submerged condenser to the reactor, wherein a gas stream leaving the top of the submerged condenser is controlled by one or more controlling elements.

Abstract: Systems and methods of producing chemical compounds are disclosed. An example chemical production system includes a combustion chamber having intake ports for entry of a gas mixture. An igniter ignites the gas mixture in the intake chamber to facilitate a reaction at a high temperature and high pressure. A nozzle restricts exit of the ignited gas mixture from the combustion chamber. An expansion chamber cools the ignited gas. The expansion chamber has an exhaust where the cooled gas exits the expansion chamber. A chemical compound product is formed in the expansion chamber.

Abstract: A process for producing urea is disclosed, wherein liquid ammonia and carbon dioxide are reacted in a high-pressure synthesis section (100), and at least part of the carbon dioxide is fed to said synthesis section (100) in liquid phase. A plant operating according to said process and a method for modernizing existing plants accordingly are also disclosed.

Abstract: Methods for synthesizing nano-urea particles are described. The methods involve using a spinning cone reactor, a nano-channel reactor, combustion synthesis or spray drying. Ammonia and carbon dioxide are used as raw materials for producing urea. The methods allow for the production of urea nanoparticles at high conversion rates. The methods allow for better control over the hydrolysis rate of the nano-urea particles. The nano-urea particles can be used as fertilizers and provide for sustained release of ammonia and its conversion to nitrates in the soil. The nano-urea particles have low volatilization rates, low moisture absorption rates and low biuret concentration. The nano-urea particles can be applied to the soil via fertigation.

Abstract: A modular system and method for producing urea from stranded natural gas includes removal of foreign particulate matter to obtain a substantially homogeneous gas. The gas is processed by controlling the quality of the stranded natural gas to maintain a substantially homogenous mixture The resultant gas stream is further cleaned and compressed to a high pressure of about 3,000 psi. The resultant ammonia stream is processed in a bypass recycling loop system at 30% conversion rate at a high pressure of about 6,000 to 7,000 psi. The equipment associated with each of the process steps may be skid mounted for portability and/or contained within the footprint of a standard 48-foot flatbed trailer.

Abstract: Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising two reactor sections, a stripper and a condenser, and a recovery section, wherein in the first reactor section a first synthesis solution is formed that is fed to the second reactor section; fresh carbon dioxide is fed to the second reactor section and in the second reactor section a second synthesis solution is formed that is fed to the stripper, wherein the second synthesis solution is stripped with the use of carbon dioxide as stripping gas and the mixed gas stream obtained in the stripper is sent to the condenser together with fresh ammonia and a carbamate stream, whereafter the condensate that is formed in the condenser is fed to the first reactor section and the urea stream that is obtained in the stripper is further purified in the recovery section, wherein the flow of the first synthesis solution from the first reactor section to the second reactor section, the flo

Abstract: A method for revamping a conventional self-stripping urea plant is disclosed, where a minor portion (18a) of the carbon dioxide feed is fed to the stripper (7) and used as a stripping agent. In further embodiments, another carbamate condenser is installed, or the conventional horizontal shell-and-tube carbamate condenser (6) is replaced with a vertical submerged unit.

Abstract: A process and a related plant layout for producing urea are disclosed, wherein the high-pressure loop (1) comprises a synthesis reactor (2), a thermal stripper (3), a condenser (4), and an adiabatic CO2 stripper (10) disposed upstream said thermal stripper, separating a vapour phase (13) containing ammonia from the urea solution (9) discharged from the reactor, and recycling said vapour phase to the reactor. The adiabatic stripper (10) can be incorporated in a reactor (200) having a top reaction zone and a bottom adiabatic stripping zone. A revamping method for a conventional urea plant in accordance with the inventive process is also disclosed.

Abstract: A process and a related plant layout for producing urea are disclosed, wherein the high-pressure loop (1) comprises a synthesis reactor (2), a thermal stripper (3), a condenser (4), and an adiabatic CO2 stripper (10) disposed upstream said thermal stripper, separating a vapour phase (13) containing ammonia from the urea solution (9) discharged from the reactor, and recycling said vapour phase to the reactor. The adiabatic stripper (10) can be incorporated in a reactor (200) having a top reaction zone and a bottom diabatic stripping zone. A revamping method for a conventional urea plant in accordance with the inventive process is also disclosed.

Abstract: A method and apparatus is provided for cleaning flue gases from combustion plants. The method includes removing dust and removing nitrogen from flue gases, bringing flue gases into contact with an aqueous ammonia solution in the presence of an oxidizing agent whereby a reaction solution forms which contains at least ammonium carbonate, heating the reaction solution such that ammonium carbonate decomposes and carbon dioxide and ammonia transfer into the gas atmosphere, and reacting the gaseous carbon dioxide and the gaseous ammonia to form urea. The apparatus includes a device for removing nitrogen and removing dust from the flue gases, a washing device downstream of the device for removing nitrogen and removing dust, a stripper downstream of the washing device, and a urea installation downstream of the stripper.

Abstract: A process for urea production from ammonia and carbon dioxide, in which part of the aqueous solution comprising urea, ammonium carbamate and ammonia obtained in a urea synthesis section is subjected to dissociation in a treatment section operating at a predetermined medium pressure for the recovery of the ammonium carbamate and of the ammonia contained in it, comprises the steps of subjecting the urea aqueous solution resulting from the aforementioned dissociation step to decomposition in a low pressure urea recovery section and of using at least a part of the condensed steam, obtained by indirect thermal exchange with a second part of said aqueous solution comprising urea, ammonium carbmate and ammonia in a high-pressure stripping unit, as a heating fluid for the dissociation of the first part of the aqueous solution comprising urea, ammonium carbmate and ammonia in the medium-pressure treatment section.

Abstract: Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising two reactor sections, a stripper and a condenser, and a recovery section, wherein in the first reactor section a first synthesis solution is formed that is fed to the second reactor section; fresh carbon dioxide is fed to the second reactor section and in the second reactor section a second synthesis solution is formed that is fed to the stripper, wherein the second synthesis solution is stripped with the use of carbon dioxide as stripping gas and the mixed gas stream obtained in the stripper is sent to the condenser together with fresh ammonia and a carbamate stream, whereafter the condensate that is formed in the condenser is fed to the first reactor section and the urea stream that is obtained in the stripper is further purified in the recovery section, wherein the flow of the first synthesis solution from the first reactor section to the second reactor section, the flo

Abstract: A modular system and method for producing urea from bio-mass includes cleaning a bio-mass feedstock to remove substantially all non-organic matter; blending the cleaned bio-mass to obtain a substantially homogeneous blend; pelletizing the blended bio-mass; and gasifying the pellets in a gasifier. The bio-mass feedstock may include bio-mass materials having different processing characteristics. The gasifying step preferably includes pulverizing the pellets to a fine particle size, injecting an organic oil into the input biomass mist when needed, and controlling the feed rate to maintain a substantially constant burn temperature. The resultant syngas stream is cleaned and compressed to a high pressure of about 6,000 to 7,000 psi. The resultant ammonia stream is processed in a bypass recycling loop system at 30% conversion rate at a high pressure of about 6,000 to 7,000 psi.

Abstract: Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising at least one reactor section, a stripper and a condenser wherein all the high-pressure equipment is placed in a low position, wherein the height of the high-pressure section is less than 35 m from ground level and at least one of the reactor sections comprises means for the separate distribution of ammonia in the bottom of the reactor section.

Abstract: Methods for synthesizing nano-urea particles are described. The methods involve using a spinning cone reactor, a nano-channel reactor, combustion synthesis or spray drying. Ammonia and carbon dioxide are used as raw materials for producing urea. The methods allow for the production of urea nanoparticles at high conversion rates. The methods allow for better control over the hydrolysis rate of the nano-urea particles. The nano-urea particles can be used as fertilizers and provide for sustained release of ammonia and its conversion to nitrates in the soil. The nano-urea particles have low volatilization rates, low moisture absorption rates and low biuret concentration. The nano-urea particles can be applied to the soil via fertigation.

Abstract: A method for co-producing electric power and urea from carbonaceous fuels such as coal, by pyrolizing the coal with oxygen to produce a raw rich gas and a hot char which is gasified with air to produce a raw lean gas. Subsequent to the cleaning of the two gases, the cleaned rich gas is made up of CO and 2H2, and the clean lean gas is made up of N2+CO. The CO in the rich gas is separated from the 2H2 and is added to the lean gas to enrich it with CO to become a lean fuel gas which fuels a gas turbine and is part of a combined cycle system which efficiently generates electric power while exhausting an off-gas (flue gas) made up of N2+CO2. The 2H2 separated from the CO, and the N2+CO2 of the exhausted flue gas are together synthesized to produce urea —CO(NH2)2.

Abstract: A process for producing urea is disclosed, wherein liquid ammonia and carbon dioxide are reacted in a high-pressure synthesis section (100), and at least part of the carbon dioxide is fed to said synthesis section (100) in liquid phase. A plant operating according to said process and a method for modernizing existing plants accordingly are also disclosed.

Abstract: Process for the preparation of urea from ammonia and carbon dioxide in a urea production process comprising, in a high-pressure synthesis section: a. a reactor, wherein ammonia and carbon dioxide react to form a urea-comprising synthesis solution; b. a stripper, wherein the urea-comprising synthesis solution is heated and stripped, optionally in counter-current with a stripping agent; c. a submerged condenser, wherein the gas leaving the top of the stripper is, at least partially, condensed to form a condensate solution and d. an ejector, in the line connecting the submerged condenser and the reactor, supporting the transport of the condensate solution from the submerged condenser to the reactor, wherein a gas stream leaving the top of the submerged condenser is controlled by one or more controlling elements.

Abstract: A process for urea production comprises a first process step in which ammonia (7) and carbon dioxide (6) are obtained, subjecting natural gas (1) to reforming treatments (12, 14), and a second step of urea (8a) production from such ammonia (7) and from carbon dioxide, through a formation of a solution comprising urea and ammonium carbamate in a urea synthesis reactor (20) and a subsequent decomposition of the ammonium carbamate and. urea recovery, the process comprises the steps of:—treating combustion smokes (5) comprising carbon dioxide with an aqueous solution (9a) comprising a part (7b) of such ammonia (7), obtaining an aqueous ammonium carbamate solution (9c);—supplying the solution (9c) thus obtained to the second process step.

Abstract: A method for modernizing a urea production plant including a urea synthesis reactor, a stripping unit and at least one condensation unit. The method includes providing: means in the condensation unit for substantially condensing at least a portion of a flow comprising ammonia and carbon dioxide in vapor phase leaving the stripping unit; a second stripping unit; means for feeding a first portion of a reaction mixture flow comprising urea, carbamate and free ammonia in aqueous solution leaving the reactor to the first stripping unit; means for feeding a second portion of the reaction mixture flow leaving the reactor to the second stripping unit; and means for feeding at least a portion of a flow comprising ammonia and carbon dioxide in vapor phase leaving the second stripping unit directly to the synthesis reactor. A de-bottlenecking of the high-pressure section downstream of the synthesis reactor may be achieved, improving production capacity.

Abstract: Systems and methods for producing urea are provided. A method for producing urea can include exchanging heat from a syngas comprising hydrogen and carbon dioxide to a urea solution comprising urea and ammonium carbamate. The heat transferred can be sufficient to decompose at least a portion of the ammonium carbamate. In one or more embodiments, the syngas can be reacted with liquid ammonia to provide a carbon dioxide lean syngas and an ammonium carbamate solution. The ammonium carbamate solution can be heated to a temperature of about 180° C. or more. At least a portion of the ammonium carbamate in the heated ammonium carbamate solution can be dehydrated to provide the urea solution.

Abstract: A method for revamping a conventional self-stripping urea plant is disclosed, where a minor portion (18a) of the carbon dioxide feed is fed to the stripper (7) and used as a stripping agent. In further embodiments, another carbamate condenser is installed, or the conventional horizontal shell-and-tube carbamate condenser (6) is replaced with a vertical submerged unit.