• 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:
    Terephthalic acid, (I), is prepd. from dimethyl terephthalate, (II), as intermediate prod., by (a) p-xylene and/or p-Me toluate (III) oxidn. with O2-contg. gases in the presence of heavy metal-contg. oxidn. catalysts at increased temp. and pressure; (b) oxidn. mixt. esterification with MeOH at increased temp. and pressure; (c) crude ester sepn. by distn. into a (III)-rich fraction, which is returned to oxidn., a residue fraction and crude (II). (d) The crude-(II) is hydrolysed continuously with water, at crude-(II): water wt. ratio 3:1 to 0.1:1, at 350 to 180 deg.C and under a pressure sufficient to maintain the liq. phase. (e) (I) is crystallised out at 300 to 100 deg.C. (f) The mother liquor is replaced by desalted water and (I) is recovered from the reaction mixt. Novelty comprises (i) introducing hot steam, at 300 to 180 deg.C, at the bottom of a multi-step hydrolysis reactor, and hot crude-(II), at 350 to 140 deg.C, to the head of the reactor. (ii) At conversion 90% or over, a reaction mixt. is drawn off at bottom as liq. phase or as solid phases suspended in the liq. phase, while an MeOH-water mixt. is drawn off at head, at 300 to 150 deg.C. (iii) The mixt. is condensed. (iv) A condensate pt. is recycled to hydrolysis reactor head, and the other pt. is returned to the process. (I) obtd. can be directly esterified with ethylene glycol and converted to fibre- and film-forming polyesters. Recycling of mono-methyl terephthalate-contg. mother liquor is unnecessary.
    公开号:SU1205757A3
    申请号:SU813357502
    申请日:1981-11-26
    公开日:1986-01-15
    发明作者:Шенген Антон；Шредер Гейнц；Шрейбер Георг
    申请人:Динамит Нобель Аг (Фирма)；
    IPC主号:
    专利说明:

    one
    This invention relates to the field of organic chemistry, in particular to a process for the preparation of terephthalic acid.
    The aim of the invention is to simplify the process.
    A mixture of methanol and water discharged as the main product of hydrolysis contains 10-90% by weight of methanol. This mixture is partially used to heat the evaporator used at the stage of distillation of dimethyl terephthalate, which reduces the energy consumption for the distillation of dimethyl terephthalate from the product of esterification.
    Part of the mixture used to heat the evaporator in the distillation of dimethyl terephthalate is fed to the rectification and the pure methanol obtained in this case is recycled to the esterification stage of the oxidation product.
    FIG. 1-3 shows a flow chart of the proposed method, with FIG. 1 and 2, the process starts from the hydrolysis stage, and in FIG. 3 shows the process for the preparation of the starting dimethyl terephthalate.
    According to FIG. 1, the water supplied as stream 1 is heated to 260-290 C in the evaporator 2 and the resulting heated water vapor under pressure of about 45-80 bar is fed to the lower part of the reactor 3, to the upper part of which dimethyl terephthalate heated to 190 C is fed (flow 4) Methanol formed in the reactor 3 as a mixture with water having a temperature of 240-250 ° C is withdrawn at condenser 5 (stream 6). I
    The reaction mixture obtained in the lower part of the reactor 3, partially recycle through the evaporator 7 and partially fed through the throttle valves in the mold 8 and 9, equipped with agitators and heat exchangers 10 and 11 (stream 12). One part of the condensate produced in the heat exchangers 10 and 11 is removed from the process, and the other part is recycled to the molds 8 and 9.
    The resulting suspension is fed to the stage of washing with hot water supplied as stream 13. The washing stage consists of three series-connected hydrocyclones 14-16. After passing through the washing step, the suspension is fed to
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    collection 17, equipped with a stirrer. From collector 17, the suspension is fed to cristatatizer 18 and 19, equipped with capacitors 20 and 21, respectively. In crystallizers 18 and 19, the suspension is adjusted to 100 C. Then the suspension is fed to a centrifuge 22, in which it is divided into terephthalic acid (stream 23) and the filtrate
    O (stream 24), the mother liquor of the washing stage is removed from the process (stream 25). Terephthalic acid is removed from the process through a dryer 26. The secondary steam of the dryer is condensed
    15 in the heat exchanger 27 and the condensate obtained is combined with the filtrate of the centrifuge 22.
    The flow chart of FIG. 2 differs from FIG. 1 only in that
    20, instead of a hydrocyclone 15, a countercurrent wash column 28 is installed. In this case, hydrocyclones 14 and 16 serve only for the concentration of solids in the suspension.
    25 according to FIG. 3 for oxidation 1, carried out at 140–470 ° C and a pressure of 4–8 bar, are served: L-xylene - via line 29; fi-toluic acid methyl ester - via pipe 30 to line 30, air - via line 31 and cobalt-manganese catalyst - via line 32,
    From the oxidation stage 1, the following is discharged: off-gas to pipeline 33; waste water — through conduit 34 and oxidation product — through conduit 35. The oxidation product is fed to the esterification I I fed through conduit 36 with methanol at 250 - 280 ° C and a pressure of 20-25 bar. The esterification product through line 37 is fed to a two-stage vacuum distillation 1V, the head product of the first stage, which is the methyl ester and -toluic acid fraction, is fed to the collector 38 by line 39, and the head product of the second stage, which is the dimethyl fraction of terephthalate , is fed through a pipeline at 40 per distillation V, carried out at 150-190 ° C, pressure of 15-tOO mbar and reflux ratio of 0.3-1. Distillation V get fraction
    55 of terephthaldehyde acid methyl ester as the main product withdrawn via conduit 41 and the dimethyl fraction 3
    terephthalate as a cubic product supplied through a pipeline for hydrolysis with water,
    In the examples, the following conditional abbreviations are accepted: DMT - dimethylterephthalate, TK - terephthalic acid, DMI / IFC - dimethyl isophthalic acid / isophthalic acid, DMO / OFA - dimethyl ether of orthophthalic acid / ophthalic acid; MTAK / TAK - methyl terephthalaldehyde acid / terephthalaldehyde acid, MMT - monomethyl terephthalate; M-TC - and toluic acid.
    Example 1. The process is carried out in the apparatus of FIGS. 1 and 3.
    400 kg / h of p-xylene and 465 kg / h of P-toluic acid methyl ester are subjected to liquid-phase oxidation 300 air at 140 ° C and a pressure of 4 bar in the presence of a catalyst consisting of 100 g of cobalt and 75 g of manganese in the form of acetates dissolved in 10% aqueous acetic acid. The resulting oxidation product is subjected to esterification with 400 kg / h of methanol at 250 s and a pressure of 20 bar. The product of etherification is subjected to continuous two-stage fractional distillation, and in the first stage the temperature is maintained in a cube of 150 ° C, a pressure of 15 mbar and a reflux ratio of 0.3, and in the second - at a temperature of 190 ° C in a cube mbar and a reflux ratio of 1.0. This yields 1264.8 kg / h of dimethyl tert-phthalate, which contains another 5.1 kg / h of DMI / IFC, 2.5 kg / h of DMO / OFK, 1.3 kg / h of MTAK / TAK and 0.6 kg / hr -TK. This stream with a temperature of 190 ° C is subjected to hydrolysis of 3587 kg / hr of water vapor having a temperature of 290 s and a pressure of 80 bar and supplied countercurrent to dimethylterephthal the. After reaching a 97.7% conversion level of dimethylteroforphalate (in terms of terephthalic acid), a mixture of 420 kg / h of methanol from 657 kg / h of water, which after condensation is used as reflux for reflux, is withdrawn from the hydrolysis stage hydrolysis and as recycling - in the process. As a bottom product from the hydrolysis stage, a stream with a temperature of 276 ° C is withdrawn, consisting of 1057.2 kg / TK, 2691.2 kg / h of water, 27.2 kg / h
    057574
    methanol, 4.4 kg / h DMI / FIC, 2.2 kg / g DMO / OFK, 1.2 kg / h MTAK / TAK, 27.2, kg / h MMT and 0.6 kg / h h -TK . The remaining bottom product is recycled to
    5 hydrolysis. After crystallization, the hydrolysis product is washed with 3000 kg / h of water with a temperature of 100 ° C. The mother liquor of the washing stage, consisting of 3243.8 kg / h of water, 55.4 kg / h of TC,
    10 12.1 kg / h of methanol, 4.0 kg / h DMI / IFC, 2.0 kg / h DMO / OFK, 0.6 kg / h MTAK / TAK 24.5 kg / h MMT and 0.54 kg / h h, removed from the process, and the washed suspension is subjected to crystallization
    15, followed by centrifugation. 1000 kg / h (89.6% of theory) of terephthalic acid are obtained with a degree
    - cleanliness 99.84%.
    Example 2. The process is carried out in a setup according to FIG. 2 and 3.
    400 kg / hh-xylene and 465 kg / h of methyl ester of h-toluic acid are subjected to liquid-phase oxidation of 300 air at 170 C and a pressure of 8 bar in the presence of a catalyst consisting of 100 g of cobalt and 75 g manganese in the form of acetates, dissolved in 10% aqueous acetic acid. , p The resulting oxidation product is subjected to the esterification of 400 kg / h of methanol at and 25 bar. The test product is subjected to continuous two-stage fractional distillation, with the first stage operating at a temperature in the cube of 150 ° C, a pressure of 15 mbar and a reflux number of 0.3, and the second - at a temperature in the cube of 190 ° C, pressure of 100 mbar and reflux ratio of 1.0 . In this case, 1266 kg / h of dime is obtained. tilterephthalate containing 30.7 kg / h DMI / IFC, 15.4 kg / h DMO / OFK, O, .13 kg / h MTAK / TAK and 6.6 kg / h h -TK. This stream with a temperature of 190 C is subjected to hydrolysis of 3676 kg / h of water vapor,
    having a temperature of 260 ° C and a pressure of 45 bar and supplied with countercurrent to dimethyl terephthalate. After reaching a conversion degree of 97.7% (in terms of terephthalic acid), the hydrolysis step removes an average temperature of 250 ° C from the hydrolysis stage
    5,433 kg / h of methanol with 677 kg / h of water, which after condensation is fed as reflux for hydrolysis and as recycling into pro50
    cess. As a bottom product from the hydrolysis stage, a stream with a temperature of 275 ° C consisting of 1057.6 kg / h of TC, 2755.2 kg / h of water, 27.8 kg / h of methanol, 26.3 kg / h of DMI is diverted / IFC, 13.1 kg / h DMO / OFK, 0.12 kg / h ITAK / TAK, 27.8 kg / h MMT and 6.6 kg / h L-TC. The remaining bottom product is recycled for hydrolysis. After crystallization, the hydrolysis product is subjected to countercurrent washing of 2250 kg / h of water with a temperature of 200 ° C,
    12057574
    The mother liquor of the washing stage consisting of 3255.2 kg h of water, 55.8 kg / h TC, 27.8 kg / h methanol 26.3 kg / h DMI / IFC, 13.2 kg / h 5 DMO / OFA, 0.09 kg / h of MTAC / TAK, 27.8 kg / h of MMT and 6.6 kg / h of AND-TK are removed from the process, and the washed suspension is subjected to crystallization, followed by centrifugation. 10 1000 kg / h (89.6% of theory) of terephthalic acid are obtained with purity of 99.998%.
    gz
    JO
    权利要求:
    Claims (1)
    [1]
    METHOD FOR PRODUCING TERPHTHALIC ACID by oxidizing h-xylene and methyl ester
    t] -toluylic acid with air in the presence of a catalyst consisting of cobalt and manganese acetates at a temperature of 140-170 ° C and a pressure of 4-8 bar, followed by esterification of the oxidate with methanol at a temperature of 250-280 C and a pressure of 20-25 bar, after which the obtained dimethyl terephthalate is subjected to distillation at a temperature of 150-190 C, a pressure of 15-100 mbar and a reflux ratio of 0.3-1.0 and hydrolysis of the obtained distillate - dimethyl terephthalate at a temperature of 260-290 ° C, followed by isolation of the target product from hydrolysis products, from characterized by the fact that, with a view to simplifying of the process, hydrolysis is carried out by supplying water vapor with a temperature of 260-290 ° C and a pressure of 45-80 bar countercurrent to dimethyl terephthalate with a temperature of 190 ° C and after reaching a conversion of dimethyl terephthalate equal to 97.7% in terms of terephthalic acid, a mixture of methanol and water with a temperature of 240-250 ° C is removed as the head product, which, after condensation, is supplied as a reflux to hydrolysis and as a recycle to the process.
    SP m sl • m
    eleven
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    同族专利:
    公开号 | 公开日
    JPH0525867B2|1993-04-14|
    FR2494684A1|1982-05-28|
    UA8349A1|1996-03-29|
    JPS5795925A|1982-06-15|
    FR2494684B1|1985-03-29|
    IT1172099B|1987-06-18|
    BR8107687A|1982-08-24|
    DE3044617C2|1985-09-26|
    IN155627B|1985-02-16|
    IT8149767D0|1981-11-25|
    DE3044617A1|1982-06-03|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3833647A|1971-09-07|1974-09-03|Lummus Co|Production of aromatic polycarboxylic acids|
    DE2916197C2|1979-04-21|1982-01-28|Dynamit Nobel Ag, 5210 Troisdorf|Process for the production of terephthalic acid from dimethyl terephthalate as an intermediate|DE3639958A1|1986-01-10|1987-07-16|Amberger Kaolinwerke Gmbh|MULTI-STAGE COUNTERFLOW ARRANGEMENT AND RELATED PROCEDURES|
    FR2611708B1|1987-02-25|1989-06-09|Elf Aquitaine|PROCESS FOR PRODUCING ALKANE-SULFONIC ACIDS|
    DE3904586A1|1989-02-16|1990-08-23|Huels Chemische Werke Ag|METHOD FOR THE PRODUCTION OF DMT INTERMEDIATE PRODUCT OF CERTAIN PURITY, AND ITS PROCESSING TO PURE DMT AND / OR MEDIUM OR HIGH PURITY TEREPHTHALIC ACID|
    EP0725054A1|1995-01-24|1996-08-07|Hüls Aktiengesellschaft|Process for preparing terephthalic acid and its isomers|
    DE19536814B4|1995-01-24|2008-03-27|Hermann-Josef Dr. Korte|A new process for the preparation of terephthalic acid and its isomers|
    MXPA03004661A|2000-11-27|2003-09-04|Teijin Ltd|Dimethyl terephthalate composition and process for producing the same.|
    JP2002167469A|2000-12-01|2002-06-11|Teijin Ltd|Recycling system for waste polyester and its method|
    WO2003033581A1|2001-10-16|2003-04-24|Teijin Limited|Method for recycling pet bottle|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE3044617A|DE3044617C2|1980-11-27|1980-11-27|Process for the production of terephthalic acid from dimethyl terephthalate as an intermediate|
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