• 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:
    1457226 Guanidine carbonate CHEMIE LINZ AG 3 July 1975 [22 July 1974] 28135/75 Heading C2C Guanidine carbonate is isolated from a dilute aqueous solution which contains guanidine, urea and pyrolysis products thereof, ammonia and carbon dioxide, by evaporating the solution at from 80‹ to 130‹ C. until a content of guanidine carbonate of at least 20 g./l. and a content of pyrolysis products of not more than 28 g./l., at an evaporation temperature of 80‹ C., or not more than 128 g./l., at an evaporation temperature of 130‹ C., is achieved, without exceeding a heating time of 6 hours at the upper limiting temperature, removing precipitated pyrolysis products, subsequently cooling the resulting solution to not more than 45‹ C., and adjusting the ammonia content of the solution to 15 to 30% by weight by adding gaseous or liquid ammonia or a concentrated aqueous solution of ammonia, and separating the resulting precipitated carbonate and, if desired, washing the precipitate with aqueous ammonia.
    公开号:SU895284A3
    申请号:SU752159065
    申请日:1975-07-22
    公开日:1981-12-30
    发明作者:Вайнроттер Фердинанд；ШМИДТ Альфред；Вегляйтнер Карлхайнц；Гарбер Альфред；Херберт Хатцль Иозеф；Сикора Рудольф
    申请人:Хеми Линц Аг (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to a method for the isolation of guanidine carbonate from dilute aqueous solutions, which, along with guanidine, urea and its pyrolysis products, also contain ammonia and carbon dioxide.
    A known method for the separation of guanidine carbonate from dilute aqueous solutions containing ammonia, carbon dioxide, urea and its pyrolysis products is that ammonia and excess carbon dioxide are distilled off from this solution at atmospheric pressure and a temperature of no higher than 80 ° C, then the solution is evaporated at pressure not higher than 0.8 atm and temperature not higher than 80 C until the solution is saturated with urea. When it is cooled to 20-30 ° C, the precipitated solid precipitate is filtered off, after which the resulting solution is suspended in liquid ammonia taken in at least a twofold excess (by weight / relative to the urea contained in the solution.
    The method allows to isolate not only guanidine carbonate from the solution, but also urea, which, in dissolved form, is again returned to the urea plant. Upon evaporation, not only guanidine carbonate, but also urea are not destroyed. The concentrator separates guanidine and urea, which is complicated by the fact that urea in quantitative terms significantly exceeds the content of the second component. Separation is carried out by the addition of ammonia, maintaining a low deposition temperature.
    The amount of ammonia used is determined by the amount of urea that must remain in dissolved form (it must be at least two times greater than the amount of urea available). The concentration of ammonia required for the complete separation of guanidine carbonate from urea is so high that it can only be achieved by using liquid ammonia. Guanidine carbonate must be completely precipitated, otherwise the urea solution cannot be returned to the urea plant, since the presence of guanidine 5dine would interfere with its normal operation ^)] The main disadvantage of this method is the vacuum evaporation, which leads to to significant economic costs. 10
    The purpose of the invention is to simplify the process.
    The goal is achieved by the method of separation of guanidine carbonate from dilute aqueous solutions containing ammonia, carbon dioxide, urea and products of its pyrolysis, which consists in the fact that these solutions are evaporated at 80-130 C and pressure
    1.3 ata, after which the precipitated pyrolysis products are filtered and then the cooled solution is treated with liquid or gaseous ammonia at 20-45 ° С until the ammonia content in the solution reaches 15-30 wt. 35 It is preferable to heat to temperatures between 105 ° and 115 ° C, with a slight overpressure (up to
    1.3 atm). Typically, the exposure time is 6 hours, which at 130 ° C is the highest limit. At an evaporation time of 2-4 hours, 130 ° C is usually sufficient. If the temperature decreases, then it is possible to increase the heating time, however, even at 110 ° C, 5-6 hours are quite enough. At 80 ° C, the heating time may still increase. Even when heated for 10 hours, excessive ammonia is not observed, firstly, for reasons of economy, and secondly, in order to avoid an excessive increase in the volume that has to be tolerated with the addition of ammonia water. The introduction of gaseous ammonia allows a more rational stage of evaporation. In this case, often it is sufficient to evaporate the mother liquor to approximately double concentration or to a water content of 80-90% in the solution.
    After establishing the required concentration of NH-j, precipitated guanidine carbonate is isolated, both by filtration and centrifugation.
    The method can be carried out not only periodically, but also continuously.
    Example 1. The mother liquor of melamine has the following
    Urea
    Guanidine (in terms of carbonate) Pyrolysis products (melamine, etc.)
    Ammonia
    Carbon dioxide
    Water composition,%:
    1.75
    0.45
    And, 1
    8.5
    The remaining t of this solution is evaporated at 107 ° C and a pressure of 1.3 atm during the solution, (12.75) (8.12) (2.33) (2.60) h to 1/6 of the volume. Get consisting, kg (%):
    Urea 24.5 Guanidine carbonate 15.6 Pyrolysis Products 4,5 Ammonia 5,0
    Water
    142.4 (74.20)
    In accordance with this composition of the bed contained in the solution of guanidine carbonate.
    At the end of evaporation, cooling should be carried out at least until the solubility of ΝΗ 3 corresponds to the required minimum concentration (15%). This usually takes place at 45 ° C. However, under certain conditions, cooling to ambient temperature can be carried out, since a higher concentration of NH ^ (more than 15%) favors the deposition conditions. Even lower temperatures can be used, while the solubility limit of other available substances is not reduced. The preferred concentration of NH-j is 20-25%.
    Ammonia can be added in any way. Preferred introduction of gas after evaporation yields (in terms of concentration in the initial solution) 51% decomposition of urea and 11% decomposition of guanidine carbonate.
    The solution is cooled, and 3.5 kg of pyrolysis products, especially melamine, are precipitated. The latter is filtered off and washed with 3.5 kg of water.
    The resulting solution has the composition, kg, (%):
    Urea 24.5 (12.75) Guanidine carbonate 15.6 (8.12) Melamine 1,0 (0.53) Ammonia 5,0 (2.60) Water 145.9 (76.00)
    ammonia until its concentration reaches 25%. Guanidinecarbo is precipitated. This solution, cooled to ambient temperature, is introduced with sodium in the amount of 11.9 to 68% yield (in terms of the mother liquor of melamine), with almost 99% purity. Precipitation itself is carried out to an amount of 76.3%. 5
    The solution remaining after separation of the guanidine carbonate has the following composition, kg (%). ’
    Urea 24.5Guanidine carbonate 3,7 to Pyrolysis Products (especially melamine) 1,0Ammonia 61.3Water 154.9 fifteen This solution may to head
    back to the continuously heated evaporator for the mother liquor. Moreover, after 3-4 circulations (under the indicated conditions), urea is almost completely decomposed, 20 while guanidine carbonate is only slightly hydrolyzed.
    Example 2. The mother liquor
    melamine composition,%:25 Urea 5.43Guanidine carbonate 2.7Melamine 0.33.Ammonia 13.57Carbon dioxide 10.63 thirty
    Water The rest is evaporated at 126 ° C and pressure
    1.3 atm for 2.5 hours to about 1/6 of the volume. After evaporation, the
    thief contains,%:35 Urea 6.65Guanidine carbonate 12.86Pyrolysis Products 7.16Ammonia 0.93Carbon dioxide 1,1 40 Water 71, 31Reached 79.6% - decompositionurea and 20.3% guanidinecarbona-
    that one.
    The solution is cooled to 45 ° C and filtered off with a 5.9% holding,%:
    Melamine
    Ameline and Amelid Mepamindianurat Melam, melem, solid phase, co
    75.6
    16,4
    4.7 melon, dicyandiamide, guanylurea, biuret, triuret
    Rest
    Liquid ammonia is passed into this solution until it is saturated (approximately 30% solution). Guanidine carbonate is precipitated in an amount of 70.8%, purely 99%. The result does not depend on the use of liquid or gaseous ammonia.
    Example 3. A mother liquor of melamine containing, g / l, (%)>
    Isanidine carbonate 74.7 (7.05)
    Urea 79.1 (7.46)
    Melamine 3.3 (0.31)
    Water 901.9 (85.18) was evaporated for 6 hours at 80 ° C to a volume of 1.6 L.
    The reaction mass is cooled and maintained at a temperature of 20 ° C. When the solution is saturated with ammonia (about 25 wt.% NH3 in solution), 51.5 g (69%) precipitates per 1 liter of the initial mother liquor, 50 g (67%) at 23 wt.% NH-и and at 16.7 wt. % NH-32, 1 g (43%) of guanidine carbonate.
    At a precipitation temperature of 45 ° C, 37.6 g (50.3%) and 58.8 g (78.9%) of guanidine carbonate are obtained by saturating the solution with ammonia.
    Example 4. Yul uterine par site of melamine of the following composition,
    7., (g): Urea 5.43 (577) Guanidine carbonate 2.7 (287) Melamine 0.33 (35) Ammonia 13.57 (1441) Carbon dioxide 10.63 (1129) Water 67.34 (7152) evaporated at 80 ° C flow 6 hours to
    1.6 liters
    After evaporation, the solution contains %, (g): Urea 21.34 (373) Guanidine carbonate 13.44 (235) Pyrolysis Products 4.13 (72) Ammonia 1.46 (25) Carbon dioxide 1,5 (26) Water 58.13 (U16), This solution is cooled to S ° C and - 3.7% are filtered out of it. solid
    a substance consisting of melamine, melam, melem, melon and other urea hydrolysis products.
    691 L of gaseous ammonia are introduced into this solution, and a solution containing 30% ammonia is obtained. 185.3 g of guanidine carbonate are precipitated from this solution, which is filtered off. The yield is 64.6% (in terms of the initial content of guanidine carbonate), purity 99%.
    Example 5. Yul uterine solution of melamine composition,%, (g):
    Urea 5.43 (577J Guanidine carbonate 2.7 (287) Melamine 0.33 (35) Ammonia 13.57 (1441) Carbon dioxide 10.63 (1129) Water 67.34 (7152)
    evaporated at 130 C for 2 h to 1.5 L.
    Obtain 1.5 l of the solution containing
    total,%, (g): Urea 6.47 (105) Guanidine carbonate 12.98 (210) Pyrolysis Products 7.34 (119) Ammonia 0.96 (16) Carbon dioxide 1, 10 (18) Water 71.15 (I52) This solution is cooled to 45 e C and 5 are filtered out of it, 97 ' (95.7 g) solid which consists of products pyrolysis and urine guilt brought-in: an example 3.
    In a solution cooled to 45 ° C, 0.25 kg of liquid ammonia is added to obtain a 157-foot ammonia solution. 75 is precipitated from this solution.
    105.6 g of guanidine carbonate. The yield is 36.87 (in terms of the content of guanidine carbonate in the initial solution), the purity is 99%.
    Isolation of guanidine carbonate according to the proposed method is more economical. This is possible due to the presence of the m-amine solution, so much urea is destroyed to ammonia and COg that the urea remains slightly larger or slightly larger than the guanidine carbonate. Due to this, the evaporation conditions are simplified, since it is not necessary to maintain a vacuum, since ammonia is captured without any difficulties and sent back to production.
    权利要求:
    Claims (4)
    [1]
    38 ammonia. Guanidine carbonate must be completely transferred to the sediment, otherwise the urea solution cannot be returned to the urea unit, since the presence of guanidine would interfere with its normal operation. The main disadvantage of the known method is that vacuum evaporation is carried out, which leads to significant economic costs. Goal invention - simplifying the process. This goal is achieved by the selection of guanidine carbonate from dilute aqueous solutions containing ammonia, carbon dioxide, urea, and its pyrolysis products, so that it is evaporated. solutions at 80–130 ° C and a pressure of 1.3 ata, after which they filter the precipitated pyrolysis products and then the cooled solution is treated with liquid or gaseous ammonia at 20–45 ° C until the content of ammonia in the solution reaches 15–30% by weight. is heated to temperatures between 105 ° and 115 ° C and a slight overpressure is required (up to approximately 1.3 atm). Typically, the exposure time is 6 hours, which at 130 ° C is the uppermost limit. With a evaporation time of 2-4 hours, 130 ° C is usually sufficient. If the temperature decreases, it is possible to increase the heating time, however, even at 110 ° C, it is quite enough for 5-6 hours. At 80 ° C, the heating time may still increase. Even when heated for 10 hours, there is no excessive decomposition contained in the guanidine carbonate solution. At the end of evaporation, cooling should be carried out, at least, until the solubility of the MN meets the required minimum concentration (15%). This usually takes place at 45 C. However, under certain conditions, cooling can be carried out at a rate of Because of its higher NH concentration (over 15%), precipitation conditions are more favorable. Even lower temperatures may be used, and the solubility limit of other existing substances is not reduced. A preferred MH concentration of 20-25%. The introduction of ammonia is possible in any way. Preference is given to the introduction of gaseous ammonia, firstly for reasons of economy, and secondly, in order to avoid an excessive increase in the volume with which ammonia water is added. The introduction of ammonia gas makes it possible to more rationally carry out the evaporation stage. In this case, it is often sufficient to evaporate the mother liquor to approximately double the concentration or to the water content in the solution of 80-90%. After the required concentration has been established, the M-precipitated guanidine carbonate is recovered, both by filtration and centrifugation. The method can be carried out not only periodically, but also continuously. Example 1. The mother solution of elamine has the following composition,%: Urea 5 Guanidine (in terms of carbonate) 1.75 Pyrolysis products (melamine, etc.) 0.45 Ammonia 11.1 Carbon dioxide 8.5 Water Total 1 t of this solution is evaporated at SUS and a pressure of 1.3 atm for hours up to 1/6 of volume. A solution is obtained which remains, kg (%): 24.5 (12.75) Urea 15.6 (8.12) Guanidinecarbonate (2.33) Pyrolysis products (2.60) Ammonia 142.4 (74.20) Water In accordance with With this composition, after evaporation, (in terms of the concentration in the initial solution) 51% decomposition of carcass and 11% decomposition of guanidine carbonate is obtained. The solution is cooled, and 3.5 kg of pyrolysis products, especially melamine, are precipitated. The latter is filtered and washed with 3.5 kg of water. The resulting solution has the composition, g, (%): (2.75) Urea (8.12) Guanidine carbonate (0.53) Melamine (2.60) Ammonia 145.9 (76.00) In this solution. chilled to ambient temperature, mimac was injected until its concentration reached 25%. Guanidinecarbo5 nat is precipitated in the amount of 11.9 to yield 68 (in terms of the mother solution of the amine), with almost 99% purity. My precipitation is up to 76.3%. The solution remaining after separation of guadincarbonate has the following composition, kg (%): Urea 24.5 Guanidine carbonate 3.7 Pyrolysis products (especially melamine) 1.0 Ammonia61.3 Water154.9 This solution can be sent back to a continuously heated evaporator solution. Moreover, after 3-4 circulation (under these conditions, the urine almost completely decomposes, while guanidine carbonate hydrates to a small extent. Example
    [2]
    2. The mother solution of melamine composition,%: 5.43 Urea 2.7 Guanidine carbonate 0.33, Melamine 13.57 Ammonia 10.63 Carbon dioxide Remaining Water and pressure is evaporated at 1.3 atm for 2.5 h about 1 / 6 volume. After evaporation, the solution contains,%: Urea 6.65 Guanidine carbonate 12.86 Pyrolysis products 7.16 Ammonia 0.93 Carbon dioxide 1.1 Water 71.31 Achievements of 79.6% decomposition of urea and 20.3% guanidine. The solution is cooled to 45 ° C and% 5.9% of the solid phase is filtered, holding:% until it is saturated (approximately 30% -H5W solution). Guany carbonate is precipitated in the amount of 70.8%, 99%. Result Does not depend on whether ammonia is used as a liquid or gaseous. Example
    [3]
    3. The mother solution of elamine, containing, g / l, (%) i 74.7 (7.05) Isanidine carbonate 79.1 (7.46) Urea 3.3 (0.31) Melamine 901.9 (85.18) is evaporated 6 hours at a volume of 1.6 liters. The reaction mass is cooled and maintain the temperature. When the solution is saturated with ammonia (about 25% by weight of MI in solution), 51.5 g (69%) is precipitated per 1 liter of the original liquor, at 23% by weight of NH- 50 g (67%) and at 16.7% by weight % NHj- 32, 1 g (43%) guanidine carbonate. At a precipitation temperature, when the solution is saturated with ammonia, 37.6 g (50.3%) and at 58.8 g (78.9%) guanidine carbonate. Example
    [4]
    4. Yul uterine melamine par par of the following composition,%, (g): Urea Guanidine carbonate Melamine Ammonia Carbon dioxide (7152) is evaporated at 1.6 liters for 6 hours. After evaporation, the solution contains,%. (g): Urea Guanidine Carbonate Pyrolysis Products Ammonia Carbon Dioxide This solution is cooled to and filtered from it 3.7% of a solid, consisting of melamine, melam, melem, melon and other products of urea hydrolysis. 691 liters of ammonia gas are introduced into this solution, a solution containing 30% ammonia is obtained. From this solution, 185.3 g of guanidine carbonate is precipitated, which is filtered off. The yield is 64.6% (based on the initial guanidinecarbolate content), purity 99%. Example 5. 10 l stock solution of melamine composition,%, (g): 5.43C577J Urea 2.7 (287) Guanidinecarbonate 0.33 (35) Melamine 13.57 (1441) Ammonia 10.63 (1129) Carbon dioxide 67, 34 (7152) is evaporated at within 2 hours to 1.5 liters. Get 1.5 l of a solution containing,%, (g): G., 47 (105) Urea 12.98 (210) Guanidinecarbonate 7.34 (119) Pyrolysis products 0.96 (16) Ammonia 1.10 (18) Carbon dioxide 71.15 (1152) This solution is cooled to 45 ° C and 5.9% (95.7 g) of the solid is filtered out of it, which consists of the products of pyrolysis of urea, given in example 3, the solution cooled to 45 ° C to Bavl to obtain a 15% ammonia solution of 0.25 kg of liquid ammonia. 105.6 g of guanidine carbonate are precipitated from this solution. The yield is 36.8% (in terms of the guanidine carbonate content in the initial solution, purity 99%. The selection of guanidine carbonate according to the proposed method is more economical. This is possible due to the failure of both urea separation and the total precipitation of guanidine carbonate. Significant at the same time, when evaporation of the MI-vapor solution is evaporated, so much urea to ammonia and C02 is destroyed, so that urea remains somewhat more or hardly more than urea carbonate. and evaporation, since it does not require maintaining a vacuum, since ammonia is captured without any difficulties and sent back to production. Formula of the invention A method for separating guanidine carbonate from dilute aqueous solutions containing ammonia, carbon dioxide, urea and its cyrolysis products , by evaporation of these solutions at elevated temperature, followed by filtration of the precipitated pyrolysis products, after which the resulting cooled solution is treated with ammonia, characterized in that tim process, evaporation is carried out at a temperature of 80-130 C and a pressure of 1.3 atm, a solution treatment is performed in liquid or gaeoobraznm .With ammonia at 20-45 until the ammonia content in the solution is 15-30 wt.%. Sources of information taken into account during the examination 1. USSR Patent No. 468404, cl. C 07 C 129/00, 1973 (prototype).
    类似技术:
    公开号 | 公开日 | 专利标题
    US3637686A|1972-01-25|Process for recovering purified melamine
    Franklin1922|The ammono carbonic acids
    US7741481B2|2010-06-22|Method for producing pure melamine
    RU2400431C2|2010-09-27|Method to purify effluents of melamine plants
    ES2209560T3|2004-06-16|PROCEDURE FOR OBTAINING PURE MELAMINE.
    SU895284A3|1981-12-30|Method of isolating guanidincarbonate from diluted aqueous solutions
    US3132143A|1964-05-05|Process for recovering melamine
    US3161638A|1964-12-15|Filter
    US3496176A|1970-02-17|Melamine purification
    US2654779A|1953-10-06|Method of preparation of guanidino fatty acids
    US3952057A|1976-04-20|Process for the preparation of guanidine carbonate
    US3448119A|1969-06-03|Producing tetramethylisoindolenine by heating acetonylacetone in aqueous ammonium salt
    Miller et al.1956|Cyanamide
    US2178510A|1939-10-31|Removal of chlorides from solutions of amino acids
    US3296266A|1967-01-03|Purification of melamine
    US5304677A|1994-04-19|Method for producing 2,6-dihydroxybenzoic acid
    US2712002A|1955-06-28|Method for purifying crude cyanuric
    US2286349A|1942-06-16|Preparation of solutions of cyanamide in liquid ammonia
    US2414303A|1947-01-14|Recovery of cysteine
    GB2060589A|1981-05-07|Method of separating off acids and bases which have been carried along in the vapours formed during distillation
    SU1030361A1|1983-07-23|Process for purifying 1-|-tetrazole
    US3121610A|1964-02-18|Process for the preparation of ammonium chloride from the liquor of an ammonia-soda process
    US2269274A|1942-01-06|Method of purifying z-aminopykimi
    US1919943A|1933-07-25|Process of making ammonium chloride
    US2417440A|1947-03-18|Preparation of guanidine salts
    同族专利:
    公开号 | 公开日
    NL7506828A|1976-01-26|
    BE831611A|1976-01-22|
    DE2435167C3|1979-02-15|
    JPS5134116A|1976-03-23|
    SE7508284L|1976-01-23|
    US3984471A|1976-10-05|
    NL175523B|1984-06-18|
    GB1457226A|1976-12-01|
    CA1038886A|1978-09-19|
    DE2435167B2|1978-06-22|
    BG27896A3|1980-01-15|
    CH595332A5|1978-02-15|
    ATA610274A|1976-08-15|
    SE424724B|1982-08-09|
    IN141743B|1977-04-09|
    DE2435167A1|1976-02-19|
    FR2279726B1|1978-02-03|
    AT336035B|1977-04-12|
    DD118621A1|1976-03-12|
    FR2279726A1|1976-02-20|
    NL175523C|1984-11-16|
    CS194722B2|1979-12-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE4405546A1|1994-02-22|1995-08-24|Nigu Chemie Gmbh|Process for the recovery of guanidine salts|DE2234732C2|1972-07-14|1983-05-05|Lentia GmbH Chem. u. pharm. Erzeugnisse - Industriebedarf, 8000 München|Process for the production of guanidine|DE3808766A1|1988-03-16|1989-09-28|Sueddeutsche Kalkstickstoff|METHOD FOR RECOVERY OF GUANIDINE HYDROHALOGENIDES FROM THE PRODUCT MIXTURES RESULTING FROM THE PRODUCTION OF MERCAPTOALKYLSILANES|
    EP3626706B1|2018-09-20|2021-06-02|Borealis Agrolinz Melamine GmbH|Method for increasing the guanidine carbonate yield in a combined melamine process and guanidine carbonate treatment process|
    EP3750872A1|2019-06-14|2020-12-16|Borealis Agrolinz Melamine GmbH|Increase of guanidine carbonate yield by reduction of mother liquor disposal and quality improvement due to increase of temperature spread|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE19742435167|DE2435167C3|1974-07-22|1974-07-22|Process for the production of guanidine carbonate from dilute, aqueous solutions|
    AT610274A|AT336035B|1974-07-22|1974-07-24|PROCESS FOR THE RECOVERY OF GUANIDINE CARBONATE FROM DILUTED AQUATIC SOLUTIONS|
    [返回顶部]