• 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:
    1. METHOD OF FRACTIONAL DE- AND SUBLIMATION OF DIANHYDRIDE OF PYROMELLITE ACID by passing pre-cooled from 430 to 210-220 ° C the reaction gases of the oxidation process of pseudocumene parallel to the thermostatically controlled surface and cooling them to 150 ° C, o and t .and in order to simplify the process, the transmission of gases is conducted at a speed of 0.1-3 m / s, using a smooth surface as a thermostatted surface. 2. The method according to A.1., About aphids and as. the fact that the transmission of gases lead at a speed of 1 m / s. 3. The method according to Claim 1, about tl and h and yushchi and the fact that as a smooth surface using a pipe or plate fridge.
    公开号:SU1039443A3
    申请号:SU782691555
    申请日:1978-11-22
    公开日:1983-08-30
    发明作者:Хаферкорн Херберт
    申请人:Феба-Хеми Аг (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to organic synthesis, in particular, to an improved method of purification of pyromellitic acid dianhydride, an important industrial product. There is a known method of purification of pyromellitic acid dianhydride by isolating it in solid state directly from a gas mixture obtained by oxidation of durol, by cooling it. Cooling is usually carried out by injecting water with U. The disadvantage of this method is that it leads to a large amount of pyromellitic acid, which must be converted to dianhydride. There is also known a method for purifying a dianhydride, consisting in washing with the obtained reaction gases (X) with water. However, the entire product is obtained in the form of an acid, which must then be dehydrated. A known method for purifying dianhydride by treating a crude product with ketone. A method for purifying dianhydride by passing hot inert gas or air at 1100–200 ° C through crude product 4 is also known. A disadvantage of these methods is that they require more complicated equipment. The closest in technical essence and the achieved result to the proposed is the method of desublimadium of pyromellitic acid dianhydride from the reaction gases of pseudocumene oxidation by their preliminary cooling from 430 to 21 220 ° C, followed by passing them parallel to the temperature-controlled with perforated cooling surface, which allows cooling the gases up to 150 ° C, i.e. temperatures above the dew point of by-products, while on the inflow side of the surface. cooling results in the release of pure pyromellitic cyanopulum dianhydride. which is separated mechanically. The disadvantage of the known method is that its application requires complicated equipment, while the target product is completely separated on the cooling surface, which necessitates its constant cleaning. The purpose of the invention is to simplify the process ... The aim is achieved in that according to the method of fractional desublimation of the pyraniumltic acid dianhydoid from the reaction gases of the pseudo-cumol oxidation process. their pre-freezing temperature from 430 to 210-220s, followed by passing them at a speed of 0.1-3 m / s (usually 1 m / s) parallel to a smooth cooling surface, usually a pipe or plate cooler, temperature-controlled at 130 ° С, on which cooling occurs until a portion of the dianhydride is released on the surface and the other comes out with a cooled gas stream. It has been established that by passing reactive gases containing pyromellitic acid dianhydride, previously cooled to a higher DOT POINT for pyromellitic acid dianhydride, i.e. up to 210-220s through a thermostated tube, the gases are cooled to a temperature above the dew point of the impurities present, i.e. up to 130-160.с, the desublimate dianhydride of pyromellitic acid partially sticks to the old pipe of the pipe, while the crystal jumps out with the cooled gas flow from the pipe and can be separated by known methods (cyclone, filter, the ratio of adhering crystals to that taken out increases when the flow rate of gases through the pipe increases, i.e. at low flow rates, a significant part of the pyromellitic acid dianhydride crystals released in the connected collector and can be drained off freely. high-purity metal product. Under a LOW flow rate, a flow rate such that gases flow through the pipe is mostly laminar. This pre-cooled. The reaction gases are further cooled and brought to a temperature above the dew point of by-products; by passing them. Partially smooth, thermostatted cooling surfaces with a speed of not more than 5 m / s, usually 1 m / s. The crystals firmly adhered in the tube should be periodically removed by known methods (washing with water, alkali 1 or solvent, mechanical cleaning or melting). Unexpected: it is the fact that it is the small flow rates that influence the precipitation ratio. Rather, it would be advisable to prevent sticking at high velocities of the gas, since this results in the mechanical effect of friction on the wall. In addition to the fact that a small amount of strongly sintered deposited crystals in a pipe, as compared with freely obtained crystals, working at a low flow rate leads to the formation of larger crystals that can more easily be deposited in the connected apparatuses (cyclone, filter). Similar observations were also made when previously. the cooled pyromellitic acid dianhydride containing reactive gases pass along thermostatted cooling surfaces of another type (for example, plate refrigerated. With a laminar flow of gases parallel to the cooling surface, since the gases are cooled, pure pyromellate acid dianhydride is obtained in the form of well-defined crystals that can it is easy to precipitate, while precipitations on the cooling plates appear after a longer period of time quantity. At high rates of gas and on such cooling surfaces, enhanced precipitation can be observed. Example p-1 (comparative). From the reaction furnace for the catalytic oxidation of isopropyl pseudocumene, the reaction gas flows into the following composition, g / m :: Dianhydride pyromellitic acid6.55. Trimellitic acid0.7 Methyl isopropylphthalic acid anhydride 0, 4 maleic anhydride 0.35 Other impurities O, 3. At 430®С gas of content T 4,7 g of dihydrate of prsmellitic acid, a. also 0.9-1.2 g with / esei per nm. The points for the dianhydride of pyromellite dianhydride (VOIC acid in this gas is about. The flow is preliminarily cooled to 210-220 s (at this temperature desublimation still does not appear). 37 Nm / h of reaction gas is passed through from top to bottom an upright double-jacketed pipe: FROM U4A-steel, bm long and with a diameter of 46 mm, which is thermally stabilized by circulating oil up to ... Gas enters, cooled to approximately, placed under the pipe of the separator With the filter connected. the flow rate in the pipe was t about 10. m / s. For 47.5 h. 1757 nm. of the reaction gas passes. There is a noticeable pressure loss in the pipe. From the collectors and the filter the output is 2.5 kg of pyromellitic acid dianhydride of low purity (99, 8%). Into the pipe: the limatia remains 5.0 kg of pyromellitic acid dihydrogen which forms a hard, densely sintered obsglochka, firmly adheres to the pipe wall. The amount released in the pipe is 67% of the total amount of dianhydride that can be obtained from the reaction gas. It is removed by rinsing with hot water. PRI m e. R 2. Through the apparatus of example 1 pass 9.7 of the same reaction gas. The average flow rate in the pipe is. 2.7 m / s. 2250 nm of gas is passed through for 232 hours. A pressure loss appears as in Example 1. 5.9 kg of pyromellitic acid dianhydride (purity 99.8%) are obtained from the collector and filter. The product in the amount of 3.8 kg remains as a shell in the pipe. Compared to the binder in example 1, a decrease in strength is observed. The amount of substance released in the pipe is 39% of the total product. P i me R 3. Through the equipment. Example 1 miss 3.6 reaction gas. The average flow velocity is about 1 m / s. Over 410 hours, 1475 of the reaction gas is passed through. There is no increase in pressure drop in the pipe. From the collector and the filter, 4.7 kg of pyremelite dianhydride acid (purity 99.9%) are obtained. 1.6 kg of product is released in the pipe, the second being separated as a very loose shell. It consists of agglomerate crystals, which can be easily enlarged. Separated from the wall. The total solids content in the pipe is 25% of the total product. Example 4. A 100 mm double-jacketed steel pipe with a diameter of 100 mm is used. / h of the indicated reaction gases. Cooling temperatures are the same as in Example 1. Average flow rate 1 m / s. During 487-h 7832 nm of gas is passed, no pressure drop is observed in the pipe. During the whole working time a loose layer of product with a thickness of about 15 mm is formed on the pipe wall, which in BpeNOT is cooling after the end of the test part. OT7 is poured in. 30.03 kg of dianhydrmd pier mellitic acid (purity 99.8%) is obtained from the collector and the filter. The remaining 3.1 kg (i.e. 9.3% of the total amount) are removed from the apparatus by means of a syringe. . EXAMPLE 5: Through a lamella plate with an effective cooling surface of 7.5 m, the distance between Lastin 120 mm and 1000 mm dlinoyplastin passed vertically upwards reaction stream in an amount of 66. With a free cross section of the refrigerator 510394 m and at an average gas temperature (at the inlet 200c t at the outlet and on the cooling plate 130 ° C), the average flow rate is 7.5 cm / s. After 562 hours of work time, the process is interrupted. 149.8 kg of 43-6 pyromellitic acid anhydride (purity 99.8%) are obtained, which are easily removed from the collector. On the cooling plates there is a loose sediment about 3-4 mm thick in the amount of 6.75 kg pyromellitic acid dianhydride (purity 99.6%) or 4.3% of the total amount obtained, which is removed by washing with water.
    权利要求:
    Claims (3)
    [1]
    1. METHOD OF FRACTIONAL DE-, SUBLIMATION OF PYROMELLITO- 1 VOIC ACID DIHANID BY TRANSMISSION OF PRE-COOLED Oxidation Process Pre-Cooled From 430 to 210-220 ° С Oxidation Process Parallel to a Thermostated Surface and Cooling them to 150 ° С, Heat The fact is that, in order to simplify the process, the transmission of gases is carried out at a speed of 0.1-3 m / s, a smooth surface is used as a thermostated surface.
    [2]
    2. The method according to claim 1, about the only one with s. the fact that the transmission of gases is carried out at a speed of 1 m / s.
    [3]
    3. The method according to claim 1, with the fact that the pipe or Plate (Refrigerator.
    SU.1039443
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    同族专利:
    公开号 | 公开日
    DE2751979A1|1979-05-23|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    BE569706A|1957-07-26|
    NL240455A|1958-06-23|
    CH472364A|1966-12-22|1969-05-15|Geigy Ag J R|Process for the preparation of a new polycyclic amine|
    FR2221574B1|1973-03-12|1976-09-10|Protex Manuf Prod Chimiq|
    US4036594A|1973-12-17|1977-07-19|Veba-Chemie Ag|Apparatus for recovering higher melting organic materials via fractional sublimation|
    DE2362659C2|1973-12-17|1982-12-23|Chemische Werke Hüls AG, 4370 Marl|Process and device for the production of higher melting organic substances by fractional desublimation|DE3421301A1|1984-06-08|1985-12-12|Hüls AG, 4370 Marl|METHOD FOR PRODUCING PYROMELLITSAEUREDIANHYDRID|
    CS253476B1|1985-07-16|1987-11-12|Jaroslav Vitovec|Method of phtalic anhydride vapours' continuous desublimation|
    JPH0584318B2|1986-03-17|1993-12-01|Nippon Catalytic Chem Ind|
    JP3908325B2|1997-04-07|2007-04-25|株式会社日本触媒|Recovery method for sublimable substances|
    US6117213A|1999-05-07|2000-09-12|Cbl Technologies, Inc.|Particle trap apparatus and methods|
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    JP4626031B2|2000-08-23|2011-02-02|三菱瓦斯化学株式会社|Method for producing high purity pyromellitic acid and high purity pyromellitic anhydride|
    JP3949371B2|2000-11-08|2007-07-25|株式会社日本触媒|How to collect reverse sublimable substances|
    JP2004067527A|2002-08-02|2004-03-04|Nippon Shokubai Co Ltd|Method for recovering sublimable substance|
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    CN102336761A|2010-12-17|2012-02-01|常熟市联邦化工有限公司|Method for capturing and purifying pyromellitic dianhydride|
    DE102015101398A1|2015-01-30|2016-08-04|Kelvion Gmbh|Discontinuous desublimator for the separation of products from gas mixtures|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE19772751979|DE2751979A1|1977-11-22|1977-11-22|PROCEDURE FOR FRACTIONAL DESUBLIMATION OF PYROMELLITIC ACIDIAN HYDRIDE|
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