The method of obtaining n-butyl acetate

 

(57) Abstract:

The invention relates to a method for producing n-butyl acetate (NBA) by the esterification of n-butyl alcohol (CHD acetic acid (CA). Getting the NBA lead in the reaction-distant column with the selection of a mixture of ether and water from the top of the column and the NBA-raw - from the bottom of the column, when the mass ratio of the NBA and the NBS irrigation columns (2-6):1, when the temperature difference of the liquid at the bottom of the column and on the plate of the input recycling (distillate distillation columns NBS and water), 25-60oWith the submission of the recycling for 3-10 theoretical plate from the top of the reaction-distant columns. CBM product of the reaction-distant columns neutralized with alkali and sent to the second column where it is separated NBS and water as distillate and bottoms distillation product of the second column is evaporated in the evaporator and distilled in the third column to produce commodity NBA purity of 99.5-and 99.8 wt. %, acid content of 0.003-0.004 wt.%, water is 0.04 to 0.08 wt.%. The yield of the final product is not less than 98 %.

The present invention relates to chemical technology, more specifically, to a method for producing n-butyl acetate (NBA) by the esterification of n-butyl alcohol (NBS) acetic acid (CA). N-butyl acetate is used as rastvorite.

A method of obtaining NBA reaction of esterification NBS acetic acid in a reactor at a temperature of 105 - 110oC in the presence of 0.1 - 0.3% of sulfuric acid as a catalyst at a molar ratio of the NBS : the criminal code, is equal to (1.1 to 1.2):1. Vapors from the reactor is sent to a distillation column with reflux at temperatures top 90 - 93oC, and then in the refrigerator, where they condense and cooled to 30oC, and the condensate is separated in a separator into two layers. The top layer containing the bulk of the NBA with impurities NBS, UK, water, neutralized with acetic acid 2% caustic soda solution. After neutralization of the product and separation in the settler organic phase is sent to a rectification order Department of the NBS and water from the NBA. As a result, the bottom of the distillation column allocate NBA purity of 85 to 93 wt.% (depending on output) with acids concentration of 0.04 wt.%. The yield of the target NBA is 82 - 90 wt.% /patent Poland 66772/.

The disadvantage of this method is the low yield and quality of the target product.

A method of obtaining NBA high purity, according to which the technical NBA received under the scheme, similar to that described above, add 15 to 20 wt.% sulfate is ralizatsii of the criminal code, then again filtered and the filtrate is subjected to distillation. The result is a target of the NBA with an acid content less than 100 hours/million, i.e. less than 0.01 wt. % (other measures of quality NBA in method not given). /Patent Romania 82484/.

The disadvantage of this method are the problems of technological and economic problems that arise during its implementation in the industry, and consists in the need to build expensive filters high throughput with significant consumption of non-regenerating ferric sulfate (up to 20 wt.% technical NBA). In addition, there is a complex problem of disposal of the resulting sludge. This method can be used in the production of small batches NBA ( 1 to 5 tons per year), but not in large-tonnage production of this product. Besides specified in the description of the method, the concentration of acetic acid in the target NBA (0.01 wt.%) does not meet modern technical requirements on NBA high purity.

According to requirements of GOST 8981-78 on the NBA brand And the higher the grade, the content of the target product should be not less than 99,0% by weight, the concentration of acid in terms of the criminal code of no more than 0.005 wt.%, water is not more than 0.1 wt.%, colour by the platinum-polucheniya NBA esterification of NBG MC in the reaction-distant apparatus in the presence of sulfuric acid as a catalyst.

In accordance with the method, on top of the machine remove the reaction water containing impurities NBA, CC, NBS (the so-called ether-water). The process leads to additional output side product, taken at a point 0.3 - 0.9 height, measured from the bottom of the tower. The lower aqueous layer side selection containing 13 - 26% of the total mass selected in the process water is removed from the system, and the upper afrosamurai layer return to the column. On bottom of the column, remove product containing 90 to 93 wt.% NBA, 0.3 to 0.5 wt.% MC, 0.1 to 0.2 wt.% water, the rest of the NBS. This mixture is neutralized 10% soda solution, the product of neutralization rectificatum and produce the target product containing 91 - 94 wt.% NBA 0,008 - 0.01 wt.% The criminal code, 0.08 to 0.1 wt. % water, the rest of the NBS. /USSR author's certificate 1143740/.

The disadvantage of this method is low quality and output allocated to the NBA (84 - 88% wt. from theoretical), and low capacity of the plant due to the fact that the process is carried out in periodic mode.

The closest in technical essence to the present invention is a method of obtaining the NBA from the NBS and the criminal code, described in the patent Romania 55369, according to which a mixture of concentrated technical criminal code and technology is about serving in the column. Reaction formation NBA is in the column and the reboiler, and the reaction water is removed at the top of the column at a temperature of 91 - 92oC in the form of an azeotrope with the NBA. The water layer is the product of condensation of vapors is withdrawn from the column, and the organic layer is returned to the first plate of the column in the form of irrigation. NBA-raw, containing 0.2 - 0.4 wt.% The criminal code, 0.2 to 0.5 wt.% water, 3 to 6 wt.% NBS, from the bottom of the reaction-distant columns sent to alembic for distillation NBA from sulfuric acid. The distillate is neutralized 5-5,5% sodium carbonate solution (neutralization is carried out using a centrifugal pump). Neutralized NBA after washing with water from salts is sent to the second distillation column, on top of a separate water mixed with NBS. VAT product of this column is sent to the power supply to the third pillar, on top of which emit NBS, and from the cube - target the NBA. The distillate of the second and third columns are combined and sent in a raw capacity of the reaction-distant columns.

In the process, get NBA purity 98 - 99 wt.% with the content of the criminal code of 0.003 - 0.01 wt.%. In proceedings of the way not listed component material balance scheme of obtaining the NBA that does not allow to judge the magnitude of viisoara the prototype. As follows from the data of example, it turns out the target NBA with the content of the basic substance schedule rate is now 99.14 wt.%, the concentration of the criminal code of 0.007 wt.%, water with 0.1 wt.% with the release of theoretical 93,6% wt. , mass fraction of non-volatile residue 0,0038% and with a high chromaticity - 18, due to the fact that in the method-prototype selection target NBA carry out from the cube to the third pillar.

The disadvantage of this method is the low yield and quality of the target product, obtained with its use, as well as significant neutralizing agent is sodium carbonate used in the method. As shown by our research, to neutralize the NBA wool, containing 0.4 wt.% The criminal code, to the concentration of the criminal code of 0.01 wt.% you need to add 2 wt.% sodium carbonate (calculated on the pure carbonate) under stirring for 60 min and a temperature of 60oC, to obtain the concentration of the criminal code of 0.003 wt.% you need to add 10% wt. carbonate under stirring for 180 min and a temperature of 100oC.

The purpose of the present invention is to increase the yield of the target NBA 96 - 98% wt. when as exceeding the above requirements of GOST.

The essence of the method consists in the following.

A mixture of NBS and the criminal code in a molar ratio of (1,02 - 1,20):1 in the presence of the P>C is sent to the quality of food in the middle part of the reaction-distant column efficiency 30 - 40 TT in Addition to the basic raw materials column 3 - 10 TT from the top of the column serves recycle the product distillate distillation columns NBS and water from the raw NBA.

Pair with the top of the column after condensation in the condenser of the refrigerator is directed to the delamination of the tank at a temperature of 30 - 40oC. the Organic phase from the sump return as irrigation on the first plate of the column, and the resulting reaction everbody output from the column.

Thermal regime of the process in the reaction-outrun the support column so that the mass ratio of the NBA : NBS irrigation of the column were in the range (2 - 6):1, and the temperature difference between the fluid at the bottom of the column and on the plate of the input cycle of the product was in the range of 25 - 60oC. At the bottom of the column output "raw" NBA containing 0.1 to 0.3 wt.% The criminal code, 1 to 5 wt.% NBS, 0.05 to 0.2 wt.% water. The specified product is neutralized 10 to 20% aqueous sodium hydroxide solution and rasclaat in the sump. The organic phase is sent to a distillation column NBS and water. Thermal regime in the support column so that the mass ratio of the NBA to the NBS in fact the authorized column. CBM product distillation columns NBS and water is directed to lighten the NBA in the evaporator or distillation column. Target NBA output at the top of the evaporator, or on top of a distillation column or lateral shoulder strap with one of the plates of the column.

It should be noted that as the process feedstock can be used not only clean the NBS and the criminal code, but a mixture containing the NBA, NBS, MC and water, for example, by-products of the production of the film (see example 11).

Thus, the important features of the proposed method are the following:

- the synthesis of the NBA in the reaction-distant column is performed with the recycling of the distillate distillation columns NBS and water for 3 - 10 TT from the top of the column (in a known way recycling is carried out in a raw capacity) and thermal regime in the column being supported, in which the ratio of the NBA to the NBS in the irrigation of the column were in the range (2 - 6):1, and in column distillation NBS and water, this ratio was 1.5 - to 3.5):1. It should be noted that the description of the prototype method, we can conclude that the ratio of the NBA to the NBS is responsible ternary azeotrope NBA - NBS - water. Specified azeotrope has a composition, wt.%: water - 37,3; NBS - 35,3; temperature and apnee mixture, L., Chemistry, 1971, 874 S./.

- the temperature difference between the bottom of the reaction-distant columns and plate input recycling must be in the range of 25 - 60oC (in the known method, the temperature difference between the bottom of the column and the plate input power does not exceed 21oC, see example 12).

The claimed ratio in the reaction-distant column and the distillation column NBS and water is practically achieved by regulating the flow of heating water vapor fed to the boilers columns, with the correction of the compositions flow irrigation columns (N. P. Liberman, Hydrocarbon Processing, 1978, v. 57, N 2, p. 93-98).

Similarly, the temperature difference between the bottom of the column and the plate enter recycle in reaction-distant column is maintained in the desired range in a cascade configuration in which the controller adjusts the temperature difference regulator flow of heating steam in the boiler or the control flow of cooling water in the condensers /W. L. Luyben. AICHE Journal, 1972, v. 18, N 1, p. 238-240/.

As follows from the examples below, it is the aggregate performance of all the foregoing features of the present invention can achieve the goal of improving yield and quality NBA.

existing GOST - a 99.0 wt.%), to reduce the concentration of acid in it to 0.003 - 0.004 wt.% (on the existing state of 0.005 wt.%, water is up 0.04 to 0.08 wt.% (on the existing state of 0.10 wt. %, non-volatile residue is not more than 0.002 wt.%. The yield of the target NBA can be upgraded to 96 - 98 wt.%. In known applicants how the output of the NBA does not exceed 94 wt.%.

Example 1 (average values of the requested parameters).

In the raw capacity of the reaction-distant columns serves 447 kg/h NBS, 345 kg/h CC, 1.5 kg/h of sulfuric acid. This mixture is heated in the heat exchanger 90oC and sent to the middle part of the reaction-distant columns, equipped with 60 cap plates (efficiency of the column is 30 TT). In addition to the raw columns, 6 TT from the top of the column serves as a recycle distillate distillation columns NBS and water in the amount of 37,87 kg/h composition, wt.%: water - 12,65; NBS - 35,57; NBA 51,78. Heat in the bottom of the column serves with the help of thermosiphon reboiler heated water vapor pressure of 6 MPa. Pair the top of the column operating at a pressure of top of 1.3 ATA, the temperature of the top 93oC are condensers, where it is cooled to 40oC, the condensate splits into an upper organic layer in the amount of 326 kg/h composition - ,0; MC - 0,09.

The organic layer is returned in the form of irrigation on the first plate of the column and the aqueous layer (everbody) put in the column of wastewater treatment, organic distillate which return in power reactive distant columns.

The mass ratio of the NBA to the NBS in irrigation reaction-distant columns equal to 4.3 : 1. Below the temperature of the reaction-distant columns equal to 142oC, on the plate of the input cycle of the product - 104oC, i.e. the temperature difference is 38oC.

From the bottom of the column output 716,88 kg/h of product composition, wt.%: water - 0,21; NBS - 3,05; NBA 95,95; MC - 0,29; sulfuric acid to 0.21; VPC - 0,29. The specified product will neutralize 34 kg/h of a 10% aqueous solution of sodium hydroxide at a temperature of 60oC and vigorous stirring for 40 minutes. The neutralized product is sent to the settling tank, where the organic phase after washing 30 kg/h of water in the amount of 702,44 kg/h composition, wt.%: water - 0,68; NBS - 2,24; NBA 96,777; MC - 0,003; VCC - 0.3 to send in the power of the column distillation NBS and water from the "raw" NBA.

The rectification is carried out in a column with a 40 cap plates (efficiency columns - 22 TT). Column operates at a pressure of top of 1.3 ATA, the temperature of the top 119o

As the distillate of the column produce the product in the quantity 37,87 kg/h composition, wt. %: water - 12,65; NBS - 35,57; NBA 51,78, which recycle 6 TT from the top of the reaction-organoclay columns.

CBM product columns in the amount of 672,21 kg/h composition, wt.%: water - 0,06; NBS - 1,42; NBA 98,207; MC - 0,003; VPC - 0,31 sent in the power of the column selection commodity in the NBA. On the top of the column at a pressure of top of 1.3 ATA, the temperature of the top 127oC, bottom 132oC, ratio of irrigation 0,1 allocate 646,21 kg/h of the target product composition, wt.%; NBA 99,65; NBS - 0,2798, MC - 0,0028, water - 0,063, VPC - 0,0044, the hue of the product is 5 units on platinum cobalt scale (scale Hazen), on other indicators of product also meets the requirements of GOST 8981-78. The yield of the target product is to 97.1 wt.% from theoretical.

It should be noted that target the same product yield and quality obtained if instead of the third distillation column to use the evaporator when the temperature of the top 127oC, bottom 130oC.

Example 2 (the lower bound of the ratio of the NBA to the NBS in irrigation reaction-distant columns).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the mass aspect] is In the process produce the target product composition, wt.%: NBA 99,54; NBS - 0,3823; MC - 0,0039; water - 0,072; VPC - 0,0018; color product - 7 units of the Product meets all other requirements of GOST.

The yield of the target NBA is 96,0 wt.% from theoretical.

Example 3 (the upper limit of the ratio of the NBA to the NBS in irrigation reaction-distant columns).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the mass ratio of the NBA to the NBS in irrigation reaction-distant columns corresponds to declare the border, namely, 6:1. In the process produce the target product composition, wt.%: NBA - owner of 99.87; NBS - 0,0882; MC - 0,0038; water is being 0.036; VPC - 0,0020; color product - 9 unit the Product meets all other requirements of GOST.

The yield of the target NBA is 97,4 wt.% from theoretical.

Example 4 (the lower bound of the ratio of the NBA to the NBS in irrigation distillation columns NBS and water).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the mass ratio of the NBA to the NBS in irrigation distillation columns NBS and water corresponds to the bottom of the claimed boundary, namely, to 1.5:1. In the process produce the target product composition, wt.%: NBA 99,58; NBS - 0,3467; MC - 0,0027; water - 0,069; VPC - 0,0016; what is the 96.3 wt.% from theoretical.

Example 5 (the upper limit of the ratio of the NBA to the NBS in irrigation distillation columns NBS and water).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the mass ratio of the NBA to the NBS in irrigation distillation columns NBS and water corresponds to declare the border, namely, a 3.5:1. In the process produce the target product composition, wt.%: NBA of 99.75; NBS - 0,1926; MC - 0,0040; water - 0,052; VPC - 0,0014; color product 5% Product meets all other requirements of GOST.

The yield of the target NBA was 98.0 wt.% from theoretical.

Example 6 (recycling the distillate distillation columns NBS and water for 3 TT from the top of the reaction-distant columns).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that recycling the distillate distillation columns NBS and water is served on 3 TT from the top of the reaction-distant columns. In the process produce the target product composition, wt.%: NBA 99,71; NBS - 0,2304; MC - 0,0039; water - 0,054; VPC - 0,0017; color product - 7 units of the Product meets all other requirements of GOST.

The yield of the target NBA is 98.5 wt.% from theoretical.

Example 7 (recycling the distillate distillation columns NBS and water for 10 TC the difference, what recycling the distillate distillation columns NBS and water is served at 10 TT from the top of the reaction-distant columns. In the process produce the target product composition, wt.%: NBA 99,52; NBS - 0,4136; MC - 0,0038; water - 0,061; VPC - 0,0016; color product - 6% Product meets all other requirements of GOST.

The yield of the target NBA is to 96.2 wt.% from theoretical.

Example 8 (comparative recycling in the raw capacity of the reaction-distant columns).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that recycling the distillate distillation columns NBS and water is served raw capacity of the reaction-distant columns. In the process produce the target product composition, wt.%: NBA 99,12; NBS - 0,7796; MC - 0,0050; water - 0,093; VPC - 0,0024; the color of the product is 12 units the Product meets all other requirements of GOST.

The yield of the target NBA is 92,2 wt.% from theoretical, i.e. significantly lower than in examples 1 to 7.

Example 9 (the lower bound of the difference between the temperature of the bottom of the reaction-distant columns and temperature input of recycling).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the difference between the temperature of the bottom of the reaction the result of the process produce the target product composition, wt.%: NBA 99,57; NBS - 0,3434; MC - 0,0047; water - 0,080; VPC - 0,0019; color product - 8% Product meets all other requirements of GOST.

The yield of the target NBA is 96,0 wt.% from theoretical.

Example 10 (the upper bound of the difference between the temperature of the bottom of the reaction-distant columns and temperature input of recycling).

The experiment was conducted with the raw materials and in modes similar to example 1 with the difference that the difference between the temperature of the bottom of the reaction-distant columns and temperature input of recycling top fits declare the border, namely, 60oC. In the process produce the target product composition, wt.%: NBA 99,82; NBS - 0,1345; MC - 0,0030; water - 0,041; VPC - 0,0015; color product 5% Product meets all other requirements of GOST.

The yield of the target NBA makes 97.9 wt.% from theoretical.

Example 11 (raw material is a by - product of the manufacture of films).

A by-product composition, wt.%: MC - 18,4; NBS - 23,4; water - 11,7; NBA 45,6; VCC - 0.9 in the amount of 1000 kg/h mixed with 1.2 kg/h of sulfuric acid, the mixture is heated to 100oC and sent to the quality of food in the middle part Riccione-distant column efficiency 30 TT in Addition to the raw stream 5 TT from B9,83; NBS - 22,79; NBA 57,38.

The process of synthesis and distillation in the reaction-distant column is carried out at a mass ratio of the NBA to the NBS in irrigation columns of 3.4 : 1, the temperature difference of the liquid columns in the cube and on the plate of the input recycling 34oC. as a result, the top of the column at a temperature of 92oC allocate 176,83 kg/hour everbody composition, wt.%: water - 98,78; NBS - 0,99; NBA - 0,20; MC - 0,03. On bottom of the column at a temperature of 142oC output 848,77 kg/h of product composition: wt%: water - 0,24; NBS - 1,43; NBA - low of 96,71; MC - 0,13; VPC - 1,35; sulfuric acid to 0.14. The specified product is subjected to neutralization with 10% sodium hydroxide solution, washed, subjected to separation in a settling tank at a temperature of 30oC and the organic phase is sent as a food column distillation NBS and water. The separation in the column is carried out at a mass ratio of the NBA to the NBS in irrigation columns of 2.8 : 1.

On the top of the column at a temperature of 116oC allocate the above recycling directed into the reaction-distant column and on the bottom at a temperature of 129oC - product number 821,4 kg/h composition, wt.%: water - 0,07; NBS - 0,47; NBA 98,056; MC - 0,004; VPC - 1,40. The specified product is sent to the power of the column selection target the NBA, on top of which emit KTA 8 units.

The yield of the target NBA is for 96.1 wt.%.

Example 12 (method prototype).

The process of obtaining the NBA carried out analogously to example 1 with the difference that the mass ratio of the NBA to the NBS in the reaction-distant column is of 1.29 : 1, column distillation, NBS and water - 1,17 : 1, and the recycle stream from the top of the column distillation NBS and water is directed into the raw capacity of the reaction-distant columns. During operation of the reaction-distant columns in this mode, which is not observed zaklepywanie columns, the maximum allowable temperature difference between the bottom of the column and the plate of the input raw material is 21oC. In the process emit the target NBA composition, wt.%: NBA - schedule rate is now 99.14; NBS - 0,7492; MC - 0,007; water - 0,10; VPC - 0,0038; the color of the product is 18 units

The yield of the target NBA is 93,6 wt.%.

The method of obtaining n-butyl acetate by esterification of n-butyl alcohol acetic acid in the reaction-distant column in the presence of an acidic catalyst of pure components or mixtures of n-butyl acetate, n-butyl alcohol, acetic acid, water allocation on the top of the column, the reaction of water with dissolved as impurities n-butyl alcohol and n-butyl is RA, high-boiling components, followed by neutralization contained in n-butyl acetate acid and cleaned of impurities in water, n-butyl alcohol, high-boiling impurities by distillation or evaporation, characterized in that the process of obtaining n-butyl acetate in the reaction-distant column is carried out at a mass ratio of n-butyl acetate and n-butyl alcohol in irrigation columns (2 - 6) : 1, and in column distillation, n-butyl alcohol and water at a mass ratio of n-butyl acetate and n-butyl alcohol in irrigation columns (1.5 - to 3.5) : 1, recycle distillate distillation columns n-butyl alcohol and water for 3 to 10 theoretical plate from the top of the reaction-distant columns when the temperature difference between the bottom of the reaction-distant columns and plate input, recycling, 25 - 60oC, and emitting the target n-butyl acetate from the cubic product distillation columns n-butyl alcohol and water by distillation or evaporation.

 

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FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid and complex (met)acrylic esters, involving the following stages: (A) reacting propane, propylene or isobutylene and/or (met)acrolein with molecular oxygen or with a gas, containing molecular oxygen through gas-phase catalytic oxidation, obtaining crude (met)acrylic acid; (B) purification of the obtained crude (met)acrylic acid, obtaining a (met)acrylic acid product; and (C) reacting raw (met)acrylic acid with alcohol, obtaining complex (met)acrylic esters, in the event that the installation used in any of the stages (B) and (C), taking place concurrently, stops. The obtained excess crude (met)acrylic acid is temporarily stored in a tank. After restoring operation of the stopped installation, the crude (met)acrylic acid, stored in the tank, is fed into the installation, used in stage (B), and/or into the installation used in stage (C). (Met)acrylic acid output of the installation used in stage (A) should be less than total consumption of (met)acrylic acid by installations used in stages (B) and (C).

EFFECT: the method allows for processing (met)acrylic acid, temporarily stored in a tank, when stage (B) or (C) stops, without considerable change in workload in stage (A).

2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining (meth)acrylic ester including stage of etherification of (meth)acrylic acid with C1-C4alcohol in presence of catalyst from highly acidic cation-exchange resin in form of immovable layer for obtaining (meth)acrylic ester; addition of polymerisation inhibitor into reactor or into distillation column for isolation; stage of isolation, at which (meth)acrylic acid that did not react is separated from reaction solution, obtained at reaction stage, where temperature in distillation column still is in the range from 60 to 100C, and pressure at the top of distillation column is in the range from 1.33 to 26.7 kPa; and recirculation stage in order to return thus obtained (meth)acrylic acid, that did not react, to reaction stage, where solid substances, contained in isolated (meth)acrylic acid that did not react and is returned to reaction stage, are isolated from it. In industry used method of obtaining (meth)acrylic esters is improved in such way as to prolong service life of used in it catalyst from highly acidic cation-exchange resin.

EFFECT: elaboration of improved method of obtaining (meth)acrylic ester.

5 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to advanced method of production of (meth)acrylic acid ester including (meth)acrylic acid purification by contacting raw (meth)acrylic acid containing manganese as an impurity manganese, and cation-exchange resin to remove manganese. To ensure contacting raw (meth)acrylic acid and cation-exchange resin, water is pre-added to (meth)acrylic acid. Besides, the method involves reaction of purified (meth)acrylic acid and alcohol with acid catalyst added.

EFFECT: method allows preventing effectively deactivation of the acid catalyst used in etherification reaction, equipment plugging and can ensure stable ester manufacturing.

3 cl, 5 tbl, 5 ex

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