Class 564/66 - Preparing directly from ammonium carbamate (i.e., from HNH-COO-HHNHH)

Subclass of Class 564 - Organic compounds -- part of the class 532-570 series
Definition: Processes in which urea is prepared directly from ammonium
No. of patents: 38
Last issue date: 06/08/2010

Number	Title	Issue Date
7732640	Process for urea production from ammonia and carbon dioxide 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 fr...	06/08/2010
7642377	Systems and methods for integrated ammonia-urea process 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 dec...	01/05/2010
7619114	Method for the modernization of a urea production plant A method for revamping a urea plant of the type comprising a synthesis section (2) having a urea synthesis reactor (5), a thermal stripping unit (7) and at least one horizontal condensation unit (6), a treatment section (3) operati...	11/17/2009
7279599	Carbamate condensation method and unit for carrying out such a method Method for carbamate condensation of a carbon dioxide/ammonia gaseous phase in a liquid phase in a condensation unit of the so-called submerged type comprising a heat exchange tube bundle having a predetermined number of tubes intended for carbamate condensation, wh...	10/09/2007
7220882	Process for urea production and plant In a process for urea production of the type comprising the reaction between ammonia and carbon dioxide in a high-pressure reactor followed by an autothermal stripping of the resulting reaction mixture so as to obtain a gaseous flow comprising ammonia and carbon dio...	05/22/2007
7094927	Process for increasing the capacity of a urea plant Process for increasing the capacity of a urea plant comprising a compression section, a high-pressure synthesis section, a urea recovery section, in which a urea melt is formed, and optionally a granulation section, the capacity of the urea plant being increased by ...	08/22/2006
6855846	Process for the preparation of urea Process for the preparation of urea from ammonia and carbon dioxide in which all or part of the liquid ammonia needed for the process is supplied to the high-pressure scrubber in such a way that it is in direct contact with the other streams supplied to this scrubbe...	02/15/2005
6730811	Process for the preparation of urea The invention relates to a process for the preparation of urea from ammonia and carbon dioxide in which the low-pressure carbamate stream formed in the further upgrading of the urea synthesis solution is stripped in a CO2-carbamate stripper in countercurr...	05/04/2004
6696026	Process for combined production of ammonia and urea A process for the combined production of ammonia and urea of the type comprising an ammonia synthesis reactor (2), a urea synthesis reactor (5) and a urea recovery section (21) stands out for the fact of submitting at least a part of a flow comprising car...	02/24/2004
6680407	Installation and process for the preparation of urea The invention relates to an installation for the preparation of urea from ammonia and carbon dioxide, the installation comprising two reactor sections in a vertically placed combined reactor and a high-pressure condenser section. The installation may comp...	01/20/2004
6649795	Process for decomposing a carbamate aqueous solution coming from the urea recovery section of a urea production plant In a process for decomposing a carbamate aqueous solution coming from a urea recovery section of a urea production plant at a predetermined temperature by indirect heat exchange with a heating fluid having a different predetermined temperature, the temper...	11/18/2003
6552224	Process and plant for the production of urea A process for urea production in a synthesis loop based on CO2 stripping is distinguished by the fact that at least part of a flow recycle carbamate is sent to a treatment of carbamate decomposition and removal of free ammonia to obtain a vapou...	04/22/2003
6538157	Method for the preparation of urea A method for the preparation of urea in a reactor using ammonia and carbon dioxide as starting materials, includes a) bringing the ammonia and carbon dioxide into contact in the reactor under conditions for the formation of carbamate; and b) decomposing t...	03/25/2003
6344588	Process for the preparation of urea In the present process for the preparation of urea, an off-gas stream released during the synthesis of melamine in a high-pressure melamine process which consists predominantly of ammonia and carbon dioxide, is introduced into at least one high-pressure s...	02/05/2002
6287525	Process and plant for urea production with reaction spaces having differentiated yields In a process for urea production, substantially pure ammonia and carbon dioxide are reacted in a main reaction space from which outgoes a reaction mixture subjected to stripping to obtain a partially purified mixture sent to a urea recovery section. From ...	09/11/2001
6118023	Method for increasing the capacity of an existing urea process Method for increasing the capacity of an existing urea process, the existing urea process comprising a reactor (R), a pressure-reduction section (SC) and a urea-recovery section (U), characterized in that (i) a stripping column (S) is added, in which ammonium ...	09/12/2000
6114579	Process for the preparation of urea In the present process for the preparation of urea, an off-gas stream released during the synthesis of melamine in a high-pressure melamine process which consists predominantly of ammonia and carbon dioxide, is introduced into at least one high-pressure s...	09/05/2000
5767313	Method for the preparation of urea The present invention relates to a process and apparatus for the preparation of urea, and in particular for urea obtained from ammonium carbamate formulated from carbon dioxide and ammonia at a pressure of about 125 bar to about 350 bar in a urea synthesi...	06/16/1998
5750780	Process for the synthesis of urea comprising two separate reaction zones A process for the synthesis of urea starting from ammonia and carbon dioxide, comprising a reaction step carried out in at least two distinct operating zones basically at the same pressure, but having a different operating temperature, the difference bein...	05/12/1998
5597454	Process for producing urea A urea production process combining lower pressure urea concentration and carbamate recovery steps into a single non-vacuum operation. Following high pressure stripping wherein a bulk of unreacted carbamate is recovered from the reaction effluent, remaini...	01/28/1997
5523482	Process and plant for the production of urea in reaction spaces with different yields In a process of producing urea in which ammonia and carbon dioxide are reacted in a first reaction space (E-1, R-1) the unreacted carbamate present in the reaction mixture is subjected to a thermal decomposition treatment, so as to obtain ammonia and carb...	06/04/1996
5403956	Process for urea production A process is described for the industrial synthesis of urea, making the ammonia (NH3) and the carbon dioxide (CO2) react, in at least one reaction space, at high pressures and temperatures and recycling at least in part the unreacted products obtained in ...	04/04/1995
5359140	Urea production process of high energy efficiency A urea production process in which the urea solution produced in the reaction zone is treated in sequence with a first thermal decomposer at the same pressure as the reaction, to decompose part of the residual ammonium carbamate into its components, then ...	10/25/1994
5316554	Method for processing crystalline ammonium carbamate Ammonium carbamate, in solution with urea, water and ammonia and under high temperature and pressure is cooled to below its crystallization temperature while being subjected to an elevated pressure. The crystallized substance formed is then dried, crushed...	05/31/1994
4988491	Flexible integration of the production of ammonia and urea The process of the present invention which produces the flexible integration for the production of ammonia and urea uses adiabatic reforming of the carbonaceous feedstock such as natural gas. With adiabatic reforming of natural gas, a surplus of carbon di...	01/29/1991
4613697	Process for the displacement to the gaseous phase of the excess of NH₃ A process for the displacement to the gaseous phase, at 80-250 Kg/cm2, of the excess NH3 contained in an aqueous urea solution, coming, at 150°-230° C., from a former stripping, isobaric with the urea synthesis, and containing also...	09/23/1986
4382800	Free amine-containing polymeric dyes Soluble polymeric colorants composed of free amine groups and chromophoric groups covalently bonded to an organic backbone are disclosed. The number of free amine groups is not less than one-half the number of chromophoric groups. The colorants are charac...	05/10/1983
4320103	Flexible integrated method for the production of ammonia and urea In an integrated flexible installation for producing ammonia and urea, the improved method which consists in that a portion of the gaseous stream comprising carbon dioxide, hydrogen and nitrogen is fed to a complementary decarbonation area and then admixe...	03/16/1982
4291006	Combined process for the production of urea and ammonia In an integrated or combined process for the production of ammonia and urea, the improvement consisting in that the absorption of CO2 from the raw gas going to the synthesis reactor for ammonia is carried out with an absorption apparatus which ...	09/22/1981
4154760	Process for controlling the temperature during urea synthesis A urea synthesis process for converting ammonia and carbon dioxide to urea is improved by providing an easy means of maintaining the urea synthesis zone in the process at a constant temperature. In the process the starting CO2 and up to and inc...	05/15/1979
4138434	Integrated ammonia-urea producing process, for the production of urea An improvement of the SNAM ammonia-stripper integrated urea process is disclosed, wherein a gaseous stream obtained by decomposing hydrocarbons is fed to an adiabatic ammonia stripper placed downstream of a carbamate decomposer, the adiabatic stripper als...	02/06/1979
4094903	Urea synthesis with improved heat recovery and conversion Heat recovery and conversion of reactants to urea are improved in adiabatic and in isothermal urea synthesis systems. Ammonia and carbon dioxide reactor feed streams are charged to a first heat exchanger external to a urea synthesis reactor and are contac...	06/13/1978
4087513	Method of hydrolyzing urea contained in waste water streams A process for hydrolyzing urea in waste water streams which comprises introducing a waste water stream containing urea into a carbon dioxide recovery system such as used in connection with the production of ammonia, and therein hydrolyzing substantially a...	05/02/1978
4066693	Process for the preparation of urea A process for preparing urea by the intermediate formation of ammonium carbamate is disclosed, wherein the process involves reduced use of high pressure steam, and the reduced production, as a by-product, of low pressure steam, compared to prior art proce...	01/03/1978
4061675	Process for the synthesis of urea from carbon dioxide and ammonia Urea is produced from ammonia synthesis effluent containing hydrogen, nitrogen, methane and argon, which is reacted with carbon dioxide to form ammonium carbamate. The hot ammonia synthesis effluent is contacted with the liquid effluents from the area syn...	12/06/1977
4042626	Integrated two-stage urea synthesis Urea synthesis in two stages, in which the first stage of ammonium carbamate formation is in indirect heat exchange with the second stage of ammonium carbamate dehydration to synthesize urea. Excess ammonia is separately preheated by heat exchange with th...	08/16/1977
4012443	Integrated urea-ammonia process Improved integrated process for simultaneous synthesis of ammonia and urea. Improved yields of urea in purified form are obtained by a simple process which curtails the addition of external water to the process. Two carbon dioxide absorbers are employed. ...	03/15/1977
4001320	Method for controlling the ammonia and CO₂ ratios in a urea manufacturing process A process for urea manufacture is described wherein the molar ratio of unreacted NH3 to CO2 (including NH3 and CO2 in the form of ammonium carbamate) in the carbamate reaction liquid phase is between 2:1 and 3:1...	01/04/1977

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Class 564/66 - Preparing directly from ammonium carbamate (i.e., from HNH-COO-HHNHH)