• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    1470489 Urea synthesis SNAMPROGETTI SpA 29 May 1975 [12 June 1974] 23531/75 Heading C2C Urea is synthesized by a) feeding a gaseous mixture comprising nitrogen, hydrogen and carbon dioxide to a first CO 2 absorption zone; (b) reacting nitrogen and hydrogen in an NH 3 synthesis zone to produce ammonia; (c) absorbing the ammonia produced in step (b) in water in an ammonia absorption zone to produce a concentrated aqueous ammonia solution; (d) feeding the concentrated aqueous ammonia solution produced in step (c) to the first CO 2 absorption zone to cause absorption of the majority of the carbon dioxide fed to that zone and to cause the production of an aqueous solution of ammonium carbamate and a gaseous stream having a carbon dioxide content reduced relative to that of the gaseous mixture; (e) feeding the aqueous solution of ammonium carbamate produced in step (d) to a urea synthesis zone in which some of the ammonium carbamate is transformed into urea; (f) discharging from the urea synthesis zone a solution comprising urea, ammonium carbamate which has not been transformed, water and ammonia; (g) feeding the discharged solution from step (f) to a stripping zone at the same or substantially the same pressure as the urea synthesis zone, to form as overhead products ammonia and carbon dioxide, and an aqueous urea solution still containing ammonia and untransformed ammonium carbamate; (h) returning the overhead products from the stripping zone, to the urea synthesis zone; (i) feeding the aqueous solution produced in step (g) to a first distillation zone at a pressure lower than that in the urea synthesis zone, to produce as a bottom product a urea solution and as an overhead product water, ammonia and carbon dioxide; (j) subjecting the overhead product from the first distillation zone to condensation and rectification to produce liquid ammonia and a concentrated aqueous solution of ammonium carbonate; (k) feeding the urea solution produced in step (i) to a second distillation zone at a pressure lower than that in the first distillation zone, to produce an aqueous solution of urea and as an overhead product upon condensation an ammoniacal solution of ammonium carbonate which is less concentrated than the concentrated solution produced in step (j); (1) discharging the aqueous solution of urea produced in (k) as the desired product; (m) feeding to the first CO 2 absorption zone the concentrated aqueous ammonium carbonate solution produced in step (j); (n) feeding to a second CO 2 absorption zone both the ammoniacal solution of ammonium carbonate produced in step (k) and the gaseous stream produced in step (d); (o) utilizing in the condensation and rectification step (j) a solution obtained as a bottom product in step (n); and (p) feeding the overhead gaseous product from the second CO 2 absorption zone in step (n) to the ammonia synthesis zone, to provide the nitrogen and hydrogen necessary for step (b).
    公开号:SU833158A3
    申请号:SU752143211
    申请日:1975-06-12
    公开日:1981-05-23
    发明作者:Бонетти Андреа
    申请人:Снампрогетти С.П.А. (Фирма)；
    IPC主号:
    专利说明:

    (54) METHOD FOR SYNTHESIS OF UREA AND AMMONIA
    This invention relates to chemical technology, in particular to a combined method for the synthesis of urea and ammonia. A known method for the synthesis of urea and ammonia, in which the CO contained in the gas stream supplied by the synthesis of ammonia is absorbed by the ammonia solution, followed by dehydration of ammonium carbonate and partial recycling of unreacted components, which are separated from the urea solution and returned as concentrated ammonium carbonate solution in the first stage and a weakly concentrated ammonium carbonate solution in the second stage fl. This method is the closest in technical essence to the proposed one. The disadvantage of this method is not sufficiently high yield of urea, about 68%. The purpose of the invention is to increase the yield of urea and reduce water consumption. The goal is achieved in the method of synthesis of urea and ammonia from conversion gases by two-step absorption with CO ammonia solution followed by dehydration of ammonium carbonate and partial recycling of unreacted components that are separated from the urea solution in two steps and return in the form of a concentrated solution of ammonium carbonate, obtained in the first stage, and a weakly concentrated solution of ammonium carbonate At the stage of urea synthesis, the concentrated ammonium carbonate solution is fed to the primary CO2 absorption zone. A distinctive feature of this method is the supply of a concentrated ammonium carbonate solution to the primary CO absorption zone. The method is carried out as follows. The source gases for ammonia synthesis, consisting of N / j, H / j, CO / j, Ar, CN4 and CO, are fed to the primary absorber CO / 2, to the top of which is fed a concentrated ammonia solution obtained by absorbing ammonia for ammonia and water synthesis. A concentrated solution of ammonium carbonate at a pressure of 16 atm is fed down the absorber.
    A solution of ammonium carbonate from the bottom of the absorber is fed to the apparatus for the synthesis of urea. The gas mixture from the first CO absorber is fed to the second CO absorber, where it is countercurrently contacted with a weakly concentrated ammonia solution of ammonium carbonate, which is obtained at 4 atm. The solution after the second scavenger is fed to a condensation column, CQj. and water, forming a concentrated ammonium carbonate solution. Ammonia is released from the solution due to the heat of formation of ammonium carbonate. This ammonia in the liquid state is fed to the urea synthesis reactor and to the hydration of gases recycled to the ammonia synthesis. From the urea synthesis reactor, the stream is fed to a desorber, where the unconverted carbamate decomposes into CO and NHj, which are recycled, and the urea solution, containing a small amount of carbamate, is fed to the distillation apparatus at 16 atm, where NH, CO and H are separated, which then condense to form a concentrated ammonium carbonate solution. The urea solution is distilled, freed from impurities.
    When implementing the method according to this method, the urea yield is 75%, against 68% in the known method, and the water consumption is reduced by 15%,
    权利要求:
    Claims (1)
    [1]
    1. US patent 3,607,339, cl. 260-555A, 1971.
    类似技术:
    公开号 | 公开日 | 专利标题
    SU833158A3|1981-05-23|Method of urea and ammonia synthesis
    NL8101209A|1981-10-01|METHOD FOR REMOVING UNRIVERSED COMPOUNDS IN THE PREPARATION OF UREA.
    IE46220B1|1983-04-06|Production of urea
    US4320103A|1982-03-16|Flexible integrated method for the production of ammonia and urea
    GB1505445A|1978-03-30|Synthesis of urea
    US3303215A|1967-02-07|Synthesis of urea
    US3725210A|1973-04-03|Method of removing unreacted materials remaining in urea synthesis effluent by plural stage distillation and co2 stripping
    US3155722A|1964-11-03|Recovery of residual ammonia and carbon dioxide in the synthesis of urea
    GB1216100A|1970-12-16|Production of urea and melamine
    US4235816A|1980-11-25|Integrated ammonia-urea process
    US3120563A|1964-02-04|Urea preparation
    US3708536A|1973-01-02|Recycling melamine synthesis offgas to urea synthesis
    SU869551A3|1981-09-30|Method of ammonia separation from carbon dioxide or their mixture
    US2046827A|1936-07-07|Production of urea and nitrogen oxides
    US3005849A|1961-10-24|Urea synthesis using excess ammonia
    US3579636A|1971-05-18|Urea synthesis process
    GB1247951A|1971-09-29|Process for preparing melamine from urea
    IE35308L|1971-10-02|Urea production
    US3527799A|1970-09-08|Urea synthesis process
    US3193353A|1965-07-06|Method of removing carbon dioxide from ammonia
    US4115449A|1978-09-19|Process for preparing a urea solution from ammonia and carbon dioxide
    US3471558A|1969-10-07|Method for the decomposition and evaporation of urea synthesis effluent
    US3470247A|1969-09-30|Process for the production of urea by synthesis of ammonia and carbon dioxide,with total recycling of the portion which has not been converted into urea
    KR870000807B1|1987-04-20|Synthesis method of urea
    US3107149A|1963-10-15|Method of separating ammonia from carbon dioxide
    同族专利:
    公开号 | 公开日
    IE41544B1|1980-01-30|
    CH605697A5|1978-10-13|
    BG29133A3|1980-09-15|
    IE41544L|1975-12-12|
    AR204277A1|1975-12-10|
    LU72705A1|1975-10-08|
    DE2526353B2|1977-03-10|
    MW3375A1|1976-10-13|
    DK241975A|1975-12-13|
    HU178091B|1982-03-28|
    PL106455B1|1979-12-31|
    JPS5113721A|1976-02-03|
    IN142473B|1977-07-16|
    BR7503716A|1976-07-06|
    JPS5714665B2|1982-03-25|
    ZM7175A1|1976-03-22|
    ATA451375A|1977-12-15|
    ZA753321B|1976-05-26|
    AU8197175A|1976-12-16|
    EG11907A|1978-03-29|
    GB1470489A|1977-04-14|
    IT1014987B|1977-04-30|
    CS188228B2|1979-02-28|
    ES438366A1|1977-05-16|
    DD118620A5|1976-03-12|
    SE7506762L|1975-12-15|
    BE830108A|1975-10-01|
    PH13614A|1980-08-07|
    FR2274610B1|1979-10-19|
    NO752079L|1975-12-15|
    MX3837E|1981-08-04|
    YU142675A|1982-02-28|
    CA1053701A|1979-05-01|
    FR2274610A1|1976-01-09|
    NL7507044A|1975-12-16|
    SE423538B|1982-05-10|
    US4012443A|1977-03-15|
    AT344722B|1978-08-10|
    RO70955A|1981-06-26|
    DE2526353A1|1975-12-18|
    TR18475A|1977-02-24|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3349126A|1962-09-10|1967-10-24|Pullman Inc|Integrated ammonia and urea process|
    ES318356A1|1964-10-16|1966-05-16|Toyo Koatsu Ind Incorporated|Method of depuration of an effluent in the obtaining of synthetic urea. |
    GB1148991A|1966-10-14|1969-04-16|Toyo Koatsu Ind Inc|Process for synthesising urea|
    DE1668732A1|1966-10-25|1971-03-25|Toyo Koatsu Ind Inc|Process for treating the unreacted ammonia and carbon dioxide contained in the synthesis of urea in the process of the synthesis autoclave|
    CH498811A|1967-05-22|1970-11-15|Chemical Construction Corp|Process for the production of urea from ammonia and carbon dioxide|
    JPS4832091B1|1968-02-12|1973-10-04|
    NL156686B|1968-03-16|1978-05-16|Stamicarbon|PROCEDURE FOR THE PREPARATION OF UREA IN COMBINATION WITH THE SYNTHESIS OF AMMONIA.|
    JPS4830258B1|1969-02-08|1973-09-18|
    JPS4919259B1|1969-08-30|1974-05-16|IT1034674B|1975-03-28|1979-10-10|Snam Progetti|FLEXIBLE INTERGRATED PROCESS FOR THE PRODUCTION OF EDUREA AMMONIA|
    IT1068268B|1976-09-09|1985-03-21|Snam Progetti|PROCEDURE FOR THE PRODUCTION OF UREA AND PURIFICATION OF WATERS|
    IT1065422B|1976-12-23|1985-02-25|Snam Progetti|INTEGRATED AMMONIA-UREA PROCESS FOR UREA PRODUCTION|
    BG35038A3|1977-05-05|1984-01-16|Montedison Spa,It|Method and installation for synthesis of urea|
    IT1094295B|1978-04-05|1985-07-26|Snam Progetti|INTEGRATED AMMONIA-UREA PROCEDURE|
    US4235816A|1979-03-08|1980-11-25|Snamprogetti S.P.A.|Integrated ammonia-urea process|
    JPS6259273B2|1979-03-26|1987-12-10|Nippon Electric Co|
    US4869887A|1987-10-30|1989-09-26|Dijk Christiaan P Van|Integrated ammonia-urea process|
    US4988491A|1989-04-11|1991-01-29|Christiaan Van Dijk|Flexible integration of the production of ammonia and urea|
    US5523483A|1995-06-16|1996-06-04|The M. W. Kellogg Company|Integrated urea/ammonia process|
    EP0905127B1|1997-09-20|2001-11-28|Urea Casale S.A.|Process for combined production of ammonia and urea|
    DE69908545T2|1999-03-16|2004-04-29|Urea Casale S.A.|Process for modernizing a urea plant|
    US6511644B1|2000-08-28|2003-01-28|The Chemithon Corporation|Method for removing contaminants in reactors|
    EP1188710A3|2000-09-15|2003-10-29|Haldor Topsoe A/S|Process for the integrated preparation of ammonia and urea|
    NL1022526C2|2003-01-30|2004-08-04|Dsm Nv|Process for separating NH3, and optionally also CO2 and H2O, from a mixture containing NH3, CO2 and H2O.|
    RU2460569C1|2011-02-10|2012-09-10|Эдуард Владимирович Юрьев|Method for modification of gas separating unitand gas separator |
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    IT23895/74A|IT1014987B|1974-06-12|1974-06-12|INTEGRATED PROCEDURE UREA AM MONIACA|
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