公开(公告)号：US4801746A

公开(公告)日：1989-01-31

申请号：US895429

申请日：1986-08-11

申请人： Victor E. A. Baenens

发明人： Victor E. A. Baenens

IPC分类号： C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/00 ,  C07C126/02

CPC分类号： C07C273/04

摘要： Process for the preparation of urea in whicha urea synthesis solution containing carbamate and free ammonia is formed in a high-pressure part in a synthesis zone at an NH.sub.3 /CO.sub.2 molar ratio of up to 4:1, a temperature of at least 175.degree. C. and the corresponding pressure,a portion of the carbamate is decomposed in a first decomposition stage at synthesis pressure or lower pressure by a stripping treatment with carbon dioxide while heat is being supplied, and the gas mixture thus obtained is at least in part condensed and the condensate and the non-condensed portion of the gas mixture, if any, are returned to the synthesis zone,a further portion of the carbamate still present is decomposed in at least two further decomposition stages and the gas mixture formed is separated, in the first of the further decomposition stages a pressure of 12-30 bar being maintained and heat being supplied and in the second of the further decomposition stages a lower pressure being maintained,and the remaining urea-containing solution is processed further by evaporation to a concentrated urea solution and, if desired, solid urea.In the first decomposition stage a portion of the urea synthesis solution is subjected to a stripping treatment with carbon dioxide while heat is being supplied, and the remaining portion of the urea synthesis solution is countercurrently contacted with carbon dioxide under adiabatic conditions. The gas mixtures obtained in both operations are at least in part condensed in a first condensation zone. The solution obtained in the treatment of the urea synthesis solution with carbon dioxide under adiabatic conditions is supplied to the first of the further decomposition stages and the stripped urea synthesis solution to the second of the further decomposition stages.

摘要翻译： 制备尿素的方法，其中在NH 3 / CO 2摩尔比高达4:1的合成区中的高压部分中形成含有氨基甲酸酯和游离氨的尿素合成溶液，温度至少为175℃ C.和相应的压力，一部分氨基甲酸酯在合成压力或较低压力下的第一分解阶段通过在加热的同时用二氧化碳进行汽提处理而分解，并且由此获得的气体混合物至少部分冷凝 并且气体混合物的冷凝物和非冷凝部分（如果有的话）返回到合成区，仍然存​​在的另一部分氨基甲酸酯在至少两个进一步的分解阶段被分解，形成的气体混合物被分离， 第一个进一步的分解阶段保持12-30bar的压力并供应热量，在第二个进一步的分解阶段中保持较低的压力，并且rema 将含尿素溶液进一步通过蒸发进一步加到浓缩的尿素溶液中，并且如果需要，则固体尿素。 在第一分解阶段，一部分尿素合成溶液在加热的同时用二氧化碳进行汽提处理，其余部分的尿素合成溶液在绝热条件下与二氧化碳逆流接触。 在两种操作中获得的气体混合物至少部分地在第一冷凝区中冷凝。 在绝热条件下用二氧化碳处理尿素合成溶液获得的溶液被提供给第一个进一步分解阶段和汽提的尿素合成溶液进入第二个进一步分解阶段。

公开(公告)号：US4207256A

公开(公告)日：1980-06-10

申请号：US651569

申请日：1976-01-22

申请人： Shigeru Inoue ,  Tadao Shirasu ,  Hisashi Miyagawa

发明人： Shigeru Inoue ,  Tadao Shirasu ,  Hisashi Miyagawa

IPC分类号： C02F1/04 ,  C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C273/16 ,  C07C126/02

CPC分类号： C07C273/04

摘要： A process for treating water vapor generated in concentrating an aqueous urea solution wherein a urea synthesis effluent containing urea, unreacted ammonium carbamate and water from a urea synthesis zone is subjected to a plurality of decomposition stages, the pressures of which stages are stepwise reduced to decompose and separate substantially all of the unreacted ammonium carbamate from the aqueous urea solution. The aqueous urea solution which still contains small amounts of ammonia and carbon dioxide is concentrated to obtain crystalline urea or molten urea substantially free of water. The water vapor generated in concentrating said aqueous urea solution which contains small amounts of ammonia and carbon dioxide is cooled for condensation thereby forming a dilute aqueous ammonium carbamate solution which is subjected to rectification under a gauge pressure below 25 kg/cm.sup.2 to distil off a gaseous mixture of water vapor, ammonia and carbon dioxide, introducing the gaseous mixture into the unreacted ammonium carbamate decomposition stage using rectification under substantially the same pressure as the pressure of the rectification for the dilute aqueous ammonium carbamate solution to remove the water vapor from the gaseous mixture, and recovering the resultant ammonia and carbon dioxide together with a gaseous mixture of ammonia and carbon dioxide which is generated in the unreacted ammonium carbamate decomposition stage.

摘要翻译： 一种处理在浓缩尿素水溶液中产生的水蒸汽的方法，其中含有尿素，未反应的氨基甲酸铵和来自尿素合成区的水的尿素合成流出物经受多个分解阶段，其阶段的压力逐步降低以分解 并将基本上所有未反应的氨基甲酸铵与尿素水溶液分离。 将含有少量氨和二氧化碳的尿素水溶液浓缩，得到基本上不含水的结晶性尿素或熔融脲。 将含有少量氨和二氧化碳的所述含尿素水溶液浓缩产生的水蒸气冷却冷凝，从而形成稀释的氨基甲酸铵水溶液，该溶液在表压低于25kg / cm 2下进行精馏以蒸发气体 水蒸气，氨和二氧化碳的混合物，将气体混合物引入未反应的氨基甲酸铵分解阶段，在与稀氨基氨基甲酸铵水溶液的精馏压力基本相同的压力下，使用精馏从气态混合物中除去水蒸汽 并且将所得的氨和二氧化碳与在未反应的氨基甲酸铵分解阶段中产生的氨和二氧化碳的气体混合物一起回收。

公开(公告)号：US4088685A

公开(公告)日：1978-05-09

申请号：US725444

申请日：1976-09-22

申请人： Ivo Mavrovic

发明人： Ivo Mavrovic

IPC分类号： B01J19/00 ,  C07C273/04 ,  C07C126/02

CPC分类号： C07C273/04 ,  B01J19/0013 ,  B01J2219/00081 ,  B01J2219/00083 ,  B01J2219/00162 ,  B01J2219/00164 ,  Y02P20/142

摘要： Heat recovery and conversion of reactants to urea are improved in adiabatic and in isothermal urea synthesis systems. Ammonia, carbon dioxide and ammonium carbamate feed streams are charged to the lower portion of a reactor, which has indirect heat exchange means positioned therein extending from the lower portion to the upper portion and which includes a heat exchange medium. Said means has a first header positioned in said upper portion, a second header positioned in the lower portion, and conduit means interconnecting the headers for passing the medium therebetween. Heat of reaction of the feed streams is imparted to the medium in the second header. The resulting reaction mixture is passed to the upper reactor portion, as is the heated medium to the first header, with heat of the medium being transferred to the reaction mixture as it is so passed.

公开(公告)号：US4301299A

公开(公告)日：1981-11-17

申请号：US203595

申请日：1980-11-03

申请人： Shigeru Inoue ,  Hiroshi Ono

发明人： Shigeru Inoue ,  Hiroshi Ono

IPC分类号： C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/02 ,  C07C126/08

CPC分类号： C07C273/04

摘要： A process for synthesizing urea in which a urea synthesis effluent obtained by reacting carbon dioxide and ammonia at urea synthesis pressures and temperatures is subjected to stripping treatment with carbon dioxide under pressures substantially equal to urea synthesis pressures to separate the unreacted carbon dioxide and ammonia contained in the urea synthesis effluent as a gaseous mixture, and a sufficient amount of said gaseous mixture to maintain the urea synthesis temperatures at a predetermined level is recycled to the urea synthesis in the gaseous state, the balance being subjected to condensation to be recycled in the liquid state to the urea synthesis.

摘要翻译： 一种合成尿素的方法，其中通过使二氧化碳和氨在尿素合成压力和温度下反应而获得的尿素合成流出物在基本上等于尿素合成压力的压力下用二氧化碳进行汽提处理，以将未反应的二氧化碳和氨 作为气态混合物的尿素合成流出物和足够量的所述气态混合物以将尿素合成温度保持在预定水平，在气态下再循环到尿素合成中，余量经过冷凝再循环到液体中 状态到尿素合成。

公开(公告)号：US4210600A

公开(公告)日：1980-07-01

申请号：US40863

申请日：1979-05-21

申请人： Umberto Zardi

发明人： Umberto Zardi

IPC分类号： B01J3/04 ,  B01J19/24 ,  C07C273/04 ,  C07C126/02

CPC分类号： B01J3/04 ,  B01J19/2425 ,  C07C273/04 ,  B01J2219/00094 ,  B01J2219/185 ,  B01J2219/1943 ,  Y02P20/142 ,  Y02P20/582

摘要： In a total recycle urea-producing system, the improvement is disclosed which consists in providing in the reactor two adjoining but separated reaction spaces, called first and second reaction zones, the surface which separates the two zones being a heat-exchanging surface. Fresh ammonia and carbon dioxide are fed with a portion of excess recycled ammonia to the first reaction zone, wherein the reaction is exothermic in character, whereas the condensates from the carbamate decomposition and the remaining portion of the excess recycled ammonia are fed to the second reaction zone, wherein the reactions are of an endothermic nature. By so doing, a better thermal balance in the reactor is obtained, concurrently with improved yields.

摘要翻译： 在总再生尿素生产系统中，公开了一种改进，其在反应器中提供称为第一和第二反应区的相邻但分离的反应空间，即分离作为热交换表面的两个区的表面。 将新鲜的氨和二氧化碳与一部分过量的再循环氨进料到第一反应区，其中反应具有放热特性，而来自氨基甲酸酯分解的冷凝物和剩余的部分过量的再循环氨进料到第二反应 区，其中反应具有吸热性质。 通过这样做，在反应器中获得更好的热平衡，同时提高了产率。

公开(公告)号：US4208347A

公开(公告)日：1980-06-17

申请号：US901816

申请日：1978-05-01

申请人： Giorgio Pagani

发明人： Giorgio Pagani

IPC分类号： C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/02

CPC分类号： C07C273/04

摘要： An improved isobaric double-recycle process is disclosed for synthesizing urea with the formation of ammonium carbamate as an intermediate, comprising effecting reaction between ammonia and carbon dioxide at high NH.sub.3 :CO.sub.2 molar ratios, a heat-treatment of the synthesis product at substantially the same pressure as that of the synthesis step and in the presence of a stripping gas, and two distinct isobaric recycles of the residual substances and of the substances in excess released from said synthesis product, said process being characterized in that:(a) said heat-treatment of the synthesis product is carried out in two consecutive stages which are isobaric or substantially isobaric with respect to the synthesis step, in the first of which stages said synthesis product is heated, whereby substantially all the residual ammonium carbamate is decomposed and the decomposition products are displaced together with part of the excess NH.sub.3, while in the second stage the remaining part of the NH.sub.3 excess is displaced by supplying supplemental heat and by injecting thereto a CO.sub.2 stream; and(b) the gas phase stripped in the first stage is immediately recycled to the synthesis step and the gas phase stripped in the second stage is subjected to a condensation and to a residual gas purge and then recycled, in the liquid state, to the synthesis step.The synthesis temperature may range from 170.degree. to 205.degree. C., the synthesis pressure from between 100 and 250 Kg/cm.sup.2, and the NH.sub.3 :CO.sub.2 molar ratio during the synthesis from 2.5:1 to 10:1.Suitable apparatus for carrying out the process is also disclosed.

摘要翻译： 公开了一种改进的等压双重循环方法，用于合成尿素形成氨基甲酸铵作为中间体，其包括在高NH 3 :CO 2摩尔比下进行氨和二氧化碳之间的反应，合成产物的热处理基本相同 所述方法的特征在于：（a）所述热处理工序，其特征在于：（a）在所述合成步骤中， 合成产物的处理在相对于合成步骤的等压或基本上同位压的两个连续阶段中进行，其中第一步是将所述合成产物加热，从而基本上所有残留的氨基甲酸铵分解，分解产物 与一部分过量的NH 3一起置换，而在第二阶段NH 3的剩余部分 通过提供补充热量并通过向其中注入二氧化碳流而使多余的物质流离失所; 和（b）将在第一阶段中汽提的气相立即循环到合成步骤，并将在第二阶段中汽提的气相进行冷凝和残留气体吹扫，然后以液态循环至 合成步骤。 合成温度范围为170〜205℃，合成压力为100〜250Kg / cm2，合成时的NH 3 :CO 2摩尔比为2.5:1〜10:1。 还公开了用于执行该方法的合适装置。

公开(公告)号：US4154760A

公开(公告)日：1979-05-15

申请号：US763148

申请日：1977-01-27

申请人： Eiji Otsuka ,  Shinji Yoshimura ,  Kazumichi Kanai ,  Shigeru Inoue

发明人： Eiji Otsuka ,  Shinji Yoshimura ,  Kazumichi Kanai ,  Shigeru Inoue

IPC分类号： C07C273/04 ,  C07C126/02

CPC分类号： C07C273/04

摘要： 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 CO.sub.2 and up to and including 100 percent of the starting NH.sub.3 are reacted in a heat-recovery zone maintained at a urea synthesis pressure. Some of the heat of reaction is removed. The molar ratio of NH.sub.3 to CO.sub.2 which is fed into the heat-recovery zone is less than 4. The reaction mixture and the rest of the starting NH.sub.3 are fed into a urea synthesis zone maintained at urea synthesis pressure to produce urea. The improvement involves adjusting the amount of starting ammonia which is fed into the urea synthesis zone in response to any change in the temperature in the urea synthesis zone so that the urea synthesis zone is maintained at a substantially fixed temperature.

摘要翻译： 通过提供将过程中的尿素合成区保持在恒定温度的简单方法，可以改善将氨和二氧化碳转化为尿素的尿素合成方法。 在该过程中，起始CO 2和直到并包括100％的起始NH 3在保持在尿素合成压力的热回收区中反应。 一些反应热被去除。 进料到热回收区中的NH 3与CO 2的摩尔比小于4.将反应混合物和其余的起始NH 3进料到维持尿素合成压力的尿素合成区中以产生尿素。 改进之处在于响应于尿素合成区中温度的任何变化而调节进入尿素合成区的起始氨的量，使得尿素合成区保持在基本上固定的温度。

公开(公告)号：US4082797A

公开(公告)日：1978-04-04

申请号：US678635

申请日：1976-04-20

申请人： Umberto Zardi ,  Vincenzo Lagana' ,  Andrea Bonetti ,  Giorgio Schmid

发明人： Umberto Zardi ,  Vincenzo Lagana' ,  Andrea Bonetti ,  Giorgio Schmid

IPC分类号： C01C1/26 ,  C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/00 ,  C07C126/02

CPC分类号： C07C273/04 ,  Y02P20/142

摘要： In a urea-synthesis installation, the problem of the condensation of the ammonium carbamate is solved by providing a condensation zone composed of a horizontal tube bundle which is placed under the static pressure of a liquid head. The ratio of the liquid head height to the diameter of the circumference encompassing the outermost tube layer of the bundle of tubes is critical: it should be between 5 and 30, 10 being the preferred value.

公开(公告)号：US4081469A

公开(公告)日：1978-03-28

申请号：US718562

申请日：1976-08-30

申请人： Hiroshi Ono ,  Shigeru Inoue

发明人： Hiroshi Ono ,  Shigeru Inoue

IPC分类号： C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/02

CPC分类号： C07C273/04 ,  Y02P20/142

摘要： Carbon dioxide is reacted with a stoichiometric excess of ammonia at urea synthesis temperatures and pressures in a urea synthesis zone with the mol ratio of ammonia to carbon dioxide being in the range of from 5:1 to 12:1. The urea synthesis effluent from the urea synthesis zone is pressurized to a pressure higher than the urea synthesis pressure, and heated to a temperature higher than the urea synthesis temperature in a separation zone, wherein unreacted ammonium carbamate and excess ammonia contained in said urea synthesis effluent are separated from urea synthesis effluent in the form of a gaseous mixture of ammonia and carbon dioxide. The thus separated gaseous mixture of ammonia and carbon dioxide is recycled to said urea synthesis zone by means of the pressure difference.

摘要翻译： 在尿素合成区的尿素合成温度和压力下，二氧化碳与化学计量过量的氨反应，氨与二氧化碳的摩尔比在5:1至12:1的范围内。 来自尿素合成区的尿素合成流出物被加压至高于尿素合成压力的压力，并加热到高于分离区中的尿素合成温度的温度，其中所述尿素合成流出物中含有未反应的氨基甲酸铵和过量氨 以氨和二氧化碳的气体混合物的形式与尿素合成流出物分离。 这样分离的氨和二氧化碳的气体混合物通过压力差再循环到所述尿素合成区。

公开(公告)号：US4061675A

公开(公告)日：1977-12-06

申请号：US710323

申请日：1976-07-30

申请人： Renzo Gagliardi

发明人： Renzo Gagliardi

IPC分类号： C01C1/02 ,  C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C126/02

CPC分类号： C07C273/04

摘要： 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 synthesis reactor to dissociate the carbamate contained in said effluents into a gaseous effluent containing ammonia, carbon dioxide and oxygen, and to produce a further liquid reaction product containing urea. Oxygen is removed from the carbamate dissociation effluent, which is then fed to the ammonia synthesis step.

摘要翻译： 尿素由含有氢，氮，甲烷和氩的氨合成流出产生，与二氧化碳反应形成氨基甲酸铵。 将热氨合成流出物与来自区域合成反​​应器的液体流出物接触以将所述流出物中所含的氨基甲酸酯分解成含有氨，二氧化碳和氧气的气态流出物，并产生含有尿素的另外的液体反应产物。 从氨基甲酸酯解离流出物中除去氧气，然后将其送入氨合成步骤。