TW201213298A - Method and apparatus for preparing multiple esters - Google Patents

Abstract

Disclosed is a method and an apparatus for manufacturing at least two esters. The method includes steps of: (a) reacting an acid and an alcohol mixture in a reactive distillation column to generate an alcohol-ester-water azeotrope, wherein the alcohol mixture includes at least two alcohols; (b) separating the alcohol-ester-water azeotrope as the organic mixture and water in a decanter; (c) purifying the organic mixture to generate the ester mixture in a stripper; and (d) performing the ester-ester separation on the ester mixture to generate at least two esters in a distillation column, wherein the number of at least two esters is the same with that of at least two alcohols.

Description

201213298 VI. Description of the invention: [Technical field to which the invention pertains] In particular, the present invention relates to a method for producing a plurality of esters in a system (equipment) relating to a method for producing vinegar and an apparatus therefor. [Prior Art]

Acetates are widely used in the industrial sector, such as paints, inks, synthetic resins, adhesives and perfumes. Ethyl acetate, ethyl acetate and isopropyl acetate are common and important alkyl C1-C4 acetates. The conventional method for producing ethyl acetate is to feed acetic acid and ethanol into a reactive steaming tower, perform a acetification reaction under the action of a catalyst, and obtain an alcohol-deuterium-water azeotrope at the top of the column. The purity of the class is not high. Moreover, the alcohol-vinegar·water azeotrope is cooled and separated from the aqueous phase and the organic phase via the liquid-liquid phase separation tank, and the organic phase is refluxed to the reactive steaming tower for purification. Ethyl acetate. In addition, another method for producing ethyl acetate by combining one reactive distillation column with one recovery column can consume a higher purity ethyl acetate product from the bottom of the recovery column, but the acid-alcohol-ester of the top portion The three-component mixture is returned to the reactive distillation column' and the alcohol-water mixture at the bottom of the reactive distillation column is reprocessed. Therefore, it takes time, process and energy to other intermediate products, and the purity of ethyl acetate has its limits. At the same time, the prior art can only invest in a series of acids and alcohols to produce esters and water. When different ester products are needed, it is necessary to redesign the reaction equipment and adjust the parameters to cause the reaction equipment to be built. The complexity and the 201213298 are not economical. In view of the deficiencies in the prior art, the applicant of the case, after careful experimentation and research, and a perseverance spirit, finally conceived the "multiple ester manufacturing methods and equipment" of the case, which can overcome the deficiencies of the prior art. A brief description. SUMMARY OF THE INVENTION In order to overcome the aforementioned drawbacks of the prior art, the present invention contemplates the esterification of two or more alcohols with an acid in a system and the thermal reflux of the intermediate product (mixed esters). Two or more kinds of esters of high purity are separately recovered by an energy-saving method, and water produced by the esterification reaction is also effectively removed from the mixed esters and individual high-purity esters. A first concept is to provide a method of making at least two esters' comprising: (a) a reactive acid feed and a mixed alcohol feed to produce a first gas bear mixture, wherein the mixed alcohol feed comprises at least two alcohols (...cooling the first gaseous mixture to produce a first liquid mixture; (separating the first liquid mixture into a second liquid mixture and water; (4) purifying a first portion of the second liquid mixture to produce a mixed ester product; And (6) distilling and mixing the ester product to produce at least two vinegars, wherein the number of at least two esters is the same as the number of at least two alcohols. (a) is carried out in a reactive distillation column, and the method further comprises feeding the acid feed and the mixed alcohol feed through the first reboiler, introducing to the reactive distillation column, and the acid in the reactive distillation column Feed back to 201213298 to the first reboiler for heating and then to the reactive distillation column. Step (C) further comprises the step (cl): placing a second portion of the second liquid mixture in the eight reactive distillation column. According to the above concept, step (b) is carried out in a liquid-liquid phase separation tank and a second gaseous mixture is also produced in step (4), the second gaseous present compound is cooled to be introduced into the liquid-liquid phase separation tank. And the step (d) further comprises the step (d1): the mixed ester is reintroduced into the vaporization tower through the second reboiler. The second concept of the present invention corresponds to the foregoing The apparatus for manufacturing a process comprising: a reactive distillation column for reacting an acid feed and mixing an alcohol feed to produce a first gaseous mixture, wherein the mixed alcohol feed comprises at least two alcohols; Separating the first liquid mixture concentrated by the first gaseous mixture into a second liquid mixture and water; a stripper for purifying the first portion of the second liquid mixture to produce a mixed ester product; and a distillation column' for distilling and mixing the ester product to produce at least two esters, wherein • The number of at least two esters is the same as the number of at least two alcohols. According to the above concept, the reactive distillation column also includes an ion exchange resin for use as an acid feed and a reaction catalyst for mixing the alcohol feed. Each of the alcohols has an alcohol number of between 2 and 5, and the acid feed comprises acetic acid. According to the above concept, the foregoing manufacturing apparatus further includes: a first reboiler 'for introducing an acid feed and mixing alcohol Feeding, introducing into the reactive distillation column, and the acid feed in the reactive distillation column is refluxed to the first reboiler for heating, and then introduced into the reactive distillation column; and the second reboiler is used for heating and mixing the ester product The first portion of the mixed ester product is then introduced into the distillation column, and the second portion of the mixed ester 201213298 product is reintroduced to the stripper. According to the above concept, at least two esters include a first ester having a first boiling point and a second ester having a second boiling point, the first boiling point being lower than the second boiling point. The manufacturing apparatus further comprises: a 4-condenser for Condensing the first ester; and a third reboiler for heating the second ester and introducing a portion of the second ester to the distillation column. [Embodiment] The "manufacture method and apparatus for a plurality of esters" proposed in the present invention will be fully understood by the following examples, so that those skilled in the art can perform the same, but the implementation of the present invention is not implemented by the following Other embodiments may be devised by those skilled in the art of the present invention, and the embodiments are intended to be within the scope of the invention. The manufacturing equipment of the various esters of the present invention mainly comprises a reactive steaming solution, a liquid liquid knife phase tank, a stripping tower and a steaming tower. An acid feed (such as acetic acid) and a mixed alcohol feed (such as ethanol and isopropanol) are reacted in a reactive distillation column to form an unpurified alcohol-ester-water azeotrope by the action of a catalyst, which is not purified. The alcohol-ester/water azeotrope is sent to the liquid-liquid phase separation tank to separate into an organic phase and an aqueous phase. The organic phase is passed to a stripping column for purification into a mixed alcohol, and the remaining alcohol and water are recovered. The purified mixed alcohol is further fed to a distillation column for ester ester separation to separately purify a plurality of esters. The number of alcohols mixed with the alcohol feed is consistent with the number of ester products via the foregoing process. The reaction formula of the foregoing embodiment is as follows. 201213298 Ethanol + Isopropanol + Acetic Acid Today Ethyl Acetate + Isopropyl Acetate + Water The method and apparatus for producing various esters in more detail are as follows.

«Month Referring to Figure 1, which is a flow chart for the manufacture of various esters of the present invention. In Figure 1, acid feed A and mixed alcohol feed B are fed via reboiler 5 to a reaction steep distillation column. In this embodiment, acid feed A is acetic acid and mixed alcohol feed B is a mixed feed of ethanol and isopropanol. However, acid feed a includes 4 and is not limited to acetic acid, other acid feeds may be used; mixed alcohol feed B includes, but is not limited to, ethanol and isopropanol, and low carbon alcohols having a carbon number of 2 i 5 It can be the reactant of this day (4). The ratio of the various alcohols in the mixed alcohol to (iv) will determine the proportion of esters ultimately made. Acid feed A and mixed alcohol feed B in the reaction distillation column 丨 reaction 4 (ie, the middle portion of the reactive distillation column 1), ion exchange tree

Ambedyst 15 (Rohm and Hass) is reacted as a solid catalyst, and the rectification section of the reactive steaming tower 1 (ie, the top portion of the reactive vapor column 1 is obtained as a first-gaseous mixture. Due to the reactants (acetic acid, ethanol) The difference between the boiling point of the isopropanol and the product (ethyl acetate, isopropyl acetate and water) is the azeotrope of the azeotrope present at 2, so that the first gaseous state obtained from the top of the column is mixed to be alcohol_vinegar_water The bottom of the reactive steaming tower 1 is of high purity: the Aim mixture is cooled to a condensate by the condenser 6. In the liquid-liquid phase separation tank 2, the 筮-' is stratified into water. Phase and organic phase 'water phase is excluded in the form of water, first-class to the top of the reactive steaming tower, and the other part of the organic phase (ie _ =

The mixture) enters the stripper 3 through the pump 7 to form an H-ester. The unpurified alcohol gt χ a , 咼 purity mixed with water and gaseous mixture is derived from the top of stripper 3 201213298 'liquefied through condenser 11 and then introduced into liquid phase separation tank 2 . The high-purity mixed ester is guided by the stripping column 3: 'heated by the reboiler 8 and then introduced into the distillation column 4 for distillation' and a part of the high-purity mixed ester is sent back to the stripping column 3 by having thermal energy. Improve purification efficiency. The lower boiling first ester (ethyl acetate 'boiling point 77.20 ° C) is obtained from the top of the distillation column 4, and the first ester can be cooled to a liquid state by the condenser 9 to the liquid c, a part of the first A vinegar can also be refluxed to the steamed tower 4 to increase its purity. At the bottom of the steaming hall ¥ 4, the first enzyme (the isopropyl acetate, the boiling point of 88.52 ° 〇), the second vinegar can be heated by the reboiler 10, and the second vinegar is reflowed. To the steaming tower 4 to increase its purity, the remaining second esters were collected as the second ester D. In the experimental example conducted according to the foregoing examples, the acid feed A (acetic acid (HAc)) and the mixed alcohol were fed. The molar ratio of material B (containing ethanol (Et〇H) and isopropanol (Ip〇H)) is U5'HAC pressure is 2 atmospheres, the flow rate is 994 km〇le/hr, and the pressure of mixed alcohol feed B is 2 atmospheres, flow rate is 1〇〇1^〇16/1^, dressing 11 and 11>011 molar ratio is 1: Bu reactants are re-reacted by re-cultivation 5 (reboiler load: 18789 kw) The distillation column (5.073 m diameter) reacts, and the first gaseous mixture is derived from the top of the column (Table 1). After the first liquid mixture is phase-separated, a part of the organic phase is refluxed to the reactive distillation column at a reflux ratio of .5 7836. 1 ' while another part of the organic phase (Table 1) was purified by entering a stripper (diameter 1.4609 m), and the unpurified alcohol-ester-water gaseous mixture was liquefied by a condenser to liquefy the mixture (Table 1 }Introduced liquid-liquid phase separation tank 2❶Water E separated by liquid-liquid phase separation tank 2 (flow rate 19 kmGie/hr, molar fraction Q 9938). The purified mixed ester passes through reboiler 8 (reboiler load is Μ% 201213298 kw), the heated mixed esters (Table 1) were sent to a distillation column (diameter 3.757 m) for distillation. The obtained first ester (ethyl acetate, EtAc, Table 1) was passed through a condenser 9, part The first ester was refluxed at a reflux ratio of 27.5 to distillation column 4. The obtained second ester (isopropyl acetate, IPAc, Table 1) was heated by reboiler 10 (reboiler load: 12262 kw). A part of the second ester is refluxed to the distillation column 4 for distillation. Table 1. Intermediates and final products of each stage in the various ester production methods

Data name flow rate kmole/hr Moer fraction IPAc EtAc H20 First gaseous mixture 1201.4 0.3501 0.4372 0.2005 Another part of organic phase 1002 0.3703 0.4744 0.1412 Heated mixed ester 99.3465 0.4976 0.4975 3.8011__5 First ester (EtAc) 49.4179 0.0002 0.99 Second ester (IPAc) 49.9286 0.99 0.01 Liquefaction mixture 73.9008 0.2158 0.0050 0.3310 As shown in Table 1, the mixed esters sent from stripper 3 contain approximately equal ethyl acetate and isopropyl acetate, and A small amount of water can finally give high purity ethyl acetate and isopropyl acetate. Therefore, the present invention can effectively carry out esterification reaction of two mixed alcohols with an acid to be purified into two high-purity esters. In addition, the embodiment of the present invention also designs the reboiler 8 for thermal integration, returns a portion of the heated mixed ester to the stripper 3, and another portion of the heated mixed ester is sent to the distillation column for ester ester separation. , can save 10% of the 201213298 source. The invention is a difficult and innovative invention, has profound industrial value, and is submitted in accordance with the law. In addition, the invention may be modified by those skilled in the art without departing from the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing the manufacture of various esters of the present invention. [Main component symbol description] 1 Reactive distillation column 7 Pump 2 Liquid-liquid phase separation tank A Acid feed 3 Stripper B Mixed alcohol feed 4 Distillation column C First ester 5, 8, 10 Reboiler D Second Ester 6, 9, 11 Condenser E Water

Claims (1)

201213298 VII. Application of the patent scope, 1. A method for producing at least two esters, comprising: (4) a reaction-acid feed and a fart alcohol feed to produce a first gaseous mixture, wherein the mixed alcohol And <&>, at least two alcohols; (8) cooling the first-gaseous mixture to produce a -th liquid mixture; (0 separating the first liquid mixture into a second liquid mixture and water; Purifying a portion A of the second liquid mixture to produce a mixed ester product; and (e) distilling the mixed ester product to produce the at least two esters, wherein the at least two The number of the genus is the same as the number of the at least two alcohols. The method of claim 1, wherein the step (4) is carried out in a reactive steam, and the method further comprises The acid feed and the mixed alcohol feed are fed through a first reboiler and introduced to the reactive distillation column, and the acid feed in the reactive distillation column is refluxed to the first reboiler for heating. Then introduce the reactive distillation column. The method of claim 2, wherein the step (c) further comprises the step (cl): introducing a second portion of the second liquid mixture into the reactive distillation column. 4. 4. The method of the invention, wherein the step is carried out in a liquid-liquid phase separation tank, and in step (d), a _ _ 罘 气-gaseous mixture is also produced, and the second gaseous mixture is cooled to be introduced into the liquid-liquid phase separation tank 5. The method of claim 1, wherein the step (e) is carried out in a distillation column, and the step (d) further comprises the step (dl): ah shouting the west class through a second re The Buddha is then introduced into the steaming tower. 201213298 6. Apparatus for producing at least two kinds of vinegar, comprising: a reactive steaming agent, using a reaction acid feed and a mixed alcohol feed to produce a a first gaseous mixture, wherein the mixed alcohol feed comprises at least two alcohols; a liquid-liquid phase separation tank' for separating a first liquid mixture concentrated by the first gaseous mixture into a second liquid mixture and water; a stripping tower' for purifying the second liquid mixture a first portion of the product to produce a mixed ester-product; and a steaming tower for distilling the mixed ester product to produce the at least two esters, wherein the number of the at least two esters 7. The apparatus of claim 6, wherein the reactive distillation column further comprises an ion parent resin for use as the acid feed and the mixed alcohol feed. 8. The apparatus of claim 6, wherein the at least two alcohols each have a carbon number between 2 and 5, the acid feed comprising #acetic acid. 9. The apparatus of claim 6, further comprising: - a -re->an apparatus for introducing the acid feed and the mixed alcohol feed, and then introducing the reactive distillation column' and The acid feed in the reactive distillation column is refluxed to the first reboiler for heating, #introduced into the reactive steaming tower; and a first re-fogper 'for heating the mixed ester product, and then mixing a first portion of the product is introduced into the distillation column and the mixture is mixed A second portion of the vinegar product is reintroduced into the gas column. The apparatus of claim 6, wherein the at least two esters comprise a first ester having a first boiling point and a second ester having a second boiling point, the first a lower boiling point than the second boiling point, the apparatus further comprising: a condenser for condensing the first ester; and a third reboiler for heating the second ester, and then the second ester A portion of the class is introduced into the distillation column. 13