WO2016182189A1

WO2016182189A1 - Method for continuously preparing hydroxypivaldehyde

Info

Publication number: WO2016182189A1
Application number: PCT/KR2016/002991
Authority: WO
Inventors: 장남진; 김기돈; 김지연; 박진호; 이선옥; 조재억
Original assignee: 한화케미칼 주식회사
Priority date: 2015-05-13
Filing date: 2016-03-24
Publication date: 2016-11-17
Also published as: KR101856763B1; KR20160133842A

Abstract

The present invention relates to a method for continuously preparing hydroxypivaldehyde. A method for continuously preparing hydroxypivaldehyde, according to the present invention, enables preparation of hydroxypivaldehyde in a high yield, and the hydroxypivaldehyde obtained by means of same is suitable for synthesizing neopentyl glycol.

Description

【Specification】

[Name of invention]

Continuous production method of hydroxyfibaldehyde

Technical Field

Cross Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0066893 filed May 13, 2015, and all content disclosed in the literature of that Korean patent application is incorporated as part of this specification. The present invention relates to a process for the continuous production of hydroxyfibaldehyde in high yield.

Background Art

Hydroxyfivalaldehyde (synonyms: 3-hydroxy-2,2-dimethylpropanal, or HPA) is an intermediate for the synthesis of neopentyl glycol, mainly aqueous formaldehyde solution and isobutylaldehyde (synonyms: 2-methylpropanal). Aldol condensation reaction is mainly produced. Neopentyl glycol is obtained by reacting HPA with hydrogenation.

Isobutyraldehyde Formaldehyde Hydroxypivalaldehyde

Hydroxypivalaldehyde Neopentyl glycol However, aqueous formaldehyde and isobutylaldehyde, which are raw materials for the preparation of HPA, have a large difference in density. Accordingly, there is a problem in that by-products of non-uniform reaction of the raw material compound increase the production of by-products and lower the production yield of HPA. As a main by-product of the aldol condensation reaction, 2,2,4-trimethyl-l, 3-pentanediol, neopentyl glycol hydroxy pivalate, neopentyl glycol isobutylate, etc. are mentioned. Because these byproducts have boiling points similar to neopentyl glycol, which make it difficult to separate from the final product and complicate the separation process, it is important to minimize byproduct generation in HPA.

In particular, since formaldehyde in the raw material for the production of HPA can act as a catalyst poison to the hydrogenation reaction of HPA, the product of the aldol condensation should be minimized the residual of formaldehyde.

In order to prevent the formation of by-products and minimize the formation of formaldehyde in the manufacturing process of HPA, it is required to improve the reaction efficiency of aqueous formaldehyde solution and isobutylaldehyde.

In this regard, HPA can be used by using improved performance of the reaction vessel, by adjusting the molar ratio or catalyst composition of the reaction product in the aldol condensation reaction reactor, or by applying a plurality of continuous stirred-tank reactors (CSTRs). Attempts have been made to improve the yield. However, the methods proposed so far require complex ^' processes ^' to overrun the installation and operating costs, or still need to be improved due to the low yield of HPA.

Prior Art Documents

[Patent literature]

(Patent Document 1) United States Patent No. 3935274 (1976.01.27)

(Patent Document 2) Republic of Korea Registered Patent No. 0231644 (1999.08.31)

[Content of invention]

[Action to be solved]

The present invention is to provide a process for the continuous production of HPA in high yield.

[Measures of problem]

According to the invention Obtaining a product containing HPA through an aldol condensation reaction of an aqueous formaldehyde solution with isobutylaldehyde in the presence of a catalyst;

The aldol condensation reaction is carried out in three or more continuous stirred reaction reactor in series,

The isobutyl aldehyde is branched into each reaction at different ratios,

The reaction mixture of the aldol condensation reaction is provided under a different residence time in each reaction period, providing a continuous method of HPA. Hereinafter, a method of continuously manufacturing HPA according to an embodiment of the present invention will be described.

Prior to this, unless otherwise stated throughout the specification, the terminology is for the purpose of referring only to particular embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. In addition, the meaning of "included" as used in the specification specifies a specific characteristic, region, integer, step, operation, element or component, excluding the addition of other specific characteristics, region, integer, step, operation, element, or component. It is not meant to be. On the other hand, formaldehyde aqueous solution and isobutylaldehyde, which are raw materials for the production of HPA, have a large difference in density, and their aldol condensation reaction is highly likely to proceed unevenly. If the aldol condensation reaction proceeds unevenly, unbanung raw material compounds (especially formaldehyde) remain in the final product, causing the reaction efficiency of the subsequent process to decrease or increase in the formation of by-products that are difficult to separate from the final product. do.

However, as a result of the continuous study of the present inventors, the aldol condensation reaction for preparing HPA was sequentially performed in a series of three or more continuous stirring reaction reactors, and isobutyl aldehyde in the raw material compound at different ratios in each reaction vessel. Significantly improved if the reaction of the aldol condensation reaction is carried out under different residence times in each reaction period at the same time as the branching It was confirmed that HPA can be produced continuously in yield.

In addition, it was confirmed that such a continuous production method can not only significantly reduce the residual amount of unbanung formaldehyde in the product containing HPA, but also effectively suppress the formation of by-products such as neopentyl glycol hydroxy pivalate.

In particular, by reducing the ratio of isobutyl aldehyde branched into each reactor in the aldol condensation reaction, sequentially increasing the residence time of the reaction in each reaction, more improved effect can be expressed.

This effect is expected to be due to the continuous manufacturing method to maximize the mixing efficiency of the raw material compound to significantly improve the efficiency of the aldol condensation reaction. In addition, the product containing the HPA obtained through the continuous manufacturing method is low in the content of unbanung formaldehyde and by-products, it can be used more suitably for the synthesis of neopentyl glycol. According to one embodiment of this invention,

Obtaining a product containing HPA through an aldol condensation reaction of an aqueous formaldehyde solution with isobutylaldehyde in the presence of a catalyst; The aldol condensation reaction is carried out in three or more continuous stirred reaction reactor in series,

The isobutyl aldehyde is branched into each reaction at different ratios,

The reaction product of the aldol condensation reaction is provided under a different residence time in each reaction vessel, thereby providing a continuous production method of HPA.

The continuous production method of HPA includes a step of obtaining a product containing HPA through an aldol condensation reaction of aqueous formaldehyde solution and isobutylaldehyde in the presence of a catalyst.

The aldol condensation reaction can be carried out in a series of three or more, preferably 3 to 5, more preferably 3 or 4 groups of continuous stirring reaction. Condensation of the aldol by increasing the number of continuous stirring reactions Although improvement in the efficiency of the reaction can be expected, it is preferable to determine the number of the reactions in consideration of the efficiency of the process and the complexity of the equipment.

FIG. 1 schematically shows one embodiment of an aldol condensation reaction system 100 comprising three continuous stirred reactors.

Referring to FIG. 1, the continuous production method of the HPA may be performed in an aldol condensation reaction system 100 including three consecutive stirring agitators (R1, R2, and R3). In the aldol condensation reaction system 100, the catalyst (F0-TEA) and the raw material compounds (FO-iBAL and F0-FA) applied to the aldol condensation reaction are introduced into the first reactor (R1) to start reaction. The reaction product is sequentially delivered to the other reactors R2 and R3 through the connecting pipes F1 and F2 to proceed with the reaction.

In particular, according to an embodiment of the present invention, isobutylaldehyde (FO-iBAL) in the raw material is branched (S1, S2 and S3) in different ratios to each of the semi-unggi (R1, R2 and R3), the aldol condensation The reactions of the reactions occur under different residence times in each reaction.

Preferably, the ratio of isobutyl aldehyde branched to each of the half aerator in the aldol condensation semi-aerator is sequentially reduced, the residence time of the semi-agitator in each of the semi-unggi may be performed to increase sequentially. Here, the deceleration width of the isobutylaldehyde content branched into each reaction vessel and the increase width of the reaction water residence time are not particularly limited.

Specifically, in the case of the aldol condensation reaction system 100 including three continuous stirred reactors R1, R2 and R3, 89 to 94 weight ⁰ / based on the total content of isobutylaldehyde added to the reaction system. Isobutyl aldehyde is charged into the first reaction vessel (R1), 5 to 10 weight ⁰ /。 isobutyl aldehyde is charged into the second reaction reactor (R2), 1 to 3 weight ⁰ /。 isobutyl Aldehyde may be added to the third reaction stage (R3). That is, in consideration of the overall efficiency of the active pattern and aldol condensation banung represented by the catalyst, the first reactor (R1) is 89 is preferable, and the third half such that input weight ^_0/0 or more isobutyl aldehyde unggi (R3) It is preferable to inject isobutylaldehyde of 3 weight ⁰ /. Or less. In particular, with the branching of the isobutylaldehyde, the residence time of the reaction product in the three consecutive stirred agitators is increased sequentially, 10 to 13 minutes in the first reaction stage (R1), the second 13 to 17 minutes in the reaction period (R2), and 1 7 to 19 minutes in the third reaction period (R3). Here, the residence time of the reaction product in each reaction vessel is described above by measuring the space velocity of the reaction product, in particular, the liquid hourly space velocity (LHSV = Reactant Liquid Flow Rate I Reactor Volume) in the aldol condensation reaction reactor. It can be adjusted within the range.

In addition, according to the embodiment of the present invention, in order to effectively stir the reaction water in each reaction vessel, the Reynolds number, the linear velocity at the tip of the impeller, the line at the wall of the reaction vessel Factors such as speed should be considered. Preferably, in the aldol condensation semi-agitator system, the Reynolds number of each semi-unggi is 50000 or more, and the difference between the linear velocity at the tip of the impeller and the wall of the reactor may be adjusted to 2 to 5 m / sec. On the other hand, the aldol condensation reaction of formaldehyde aqueous solution and isobutylaldehyde is exothermic reaction. Therefore, it is preferable to remove the semiungung heat while circulating the semiungung of each halfunggi to the outside of the semiungunggi. In particular, in circulating the reaction product to the outside, by using the injector equipped with a venturi nozzle (strong) spraying the reactant in the reaction vessel it can be ensured more improved reaction efficiency.

According to the embodiment of the present invention, the aldol condensation reaction may be performed in three or more continuous stirring reactors connected in series via a reaction medium circulation unit including a circulation pump, a heat exchanger, and a reaction water injector, respectively. FIG. 2 ^′ schematically shows an embodiment in which the reaction water circulation unit is applied to the aldol condensation reaction system according to FIG. 1.

Referring to Figure 2, the aldol condensation reaction can be carried out in three continuous stirred reactors (R1, R2 and R3) connected in series via a semi-acupuncture circulation unit (CU), respectively. Here, the semi-ungmul circulation unit (CU) for circulating a portion of the semi-ungmul in each half-unggi through the circulation pipe to the outside of the half-unggi Circulation pump (P), a heat exchanger (E) for removing the reaction heat from the reactionary water passing through the circulation pipe, and a semi-atomizer injecting a portion of the reaction product passing through the circulation pipe through the venturi nozzle to the next reactor ( V). Here, the venturi nozzle may be provided where not only the semi-atom water injector (V) but also the semi-ung water passing through the heat exchanger (E) flows into each of the half aungers.

In the aldol condensation reaction system, the reaction heat is removed while circulating 5 to 20 times the total amount of the reaction product through the reaction water circulation unit (CU), and at this time, by applying kinetic energy to the reaction water through a venturi nozzle, Stirring efficiency can be increased significantly.

Even under the aldol condensation reaction system to which the semi-aungrel circulation unit (CU) is applied, the ratio of isobutylaldehyde branched to each of the half aungers may be sequentially decreased, and the residence time of the counterungung at each of the semiaunggi may be sequentially increased. have. However, when the reactant circulation unit (CU) is applied, since the reaction product is circulated to the outside of the reaction vessel, the residence time of the reactants in each reaction vessel may be relatively short.

By way of non-limiting example, the residence time of the reaction product in the three continuous stirred reaction reactors to which the reaction water circulation unit (CU) is applied, is increased in sequence, 1 to 2 minutes at the first reaction period (R1), It can be adjusted from 1.5 to 5 minutes in the second reaction stage (R2), and from 5 to 9 minutes in the third reaction stage (R3). On the other hand, in the aldol condensation banung, isobutyl aldehyde as is advantageous in that the amount of isomer used to 0.5 ^_0/0 of less than suppressing the formation of by-products. ᅳ

In addition, isobutylaldehyde may be used in a molar ratio of 1 1 to 1.5, preferably 1/1 to 1.2 with respect to 1 mol of formaldehyde. That is, in order to induce a complete reaction of the formaldehyde used in the aldol condensation reaction, isobutylaldehyde may be used in excess of formaldehyde, preferably in a molar ratio of 1: 1.1 or more. However, when isobutyl aldehyde is used too much, the production of by-products due to Tishchenko banung may be increased. Therefore, isobutyl aldehyde is less than 1: 1.5 compared to formaldehyde It is preferable to use in molar ratio.

In the above-mentioned aldol condensation reaction, it is advantageous to use formin having a concentration of formaldehyde in an amount of 35 to 45 wt./°. For the improvement of reaction efficiency and reduction of waste water generation. And, in general, there is a formaldehyde aqueous solution was added to methane in order to prevent the polymerization of formaldehyde, the content is preferably 0.1 -5 weight ⁰ /. With respect to the formaldehyde solution.

In the aldol condensation reaction, the catalyst may be a hydroxide such as LiOH, NaOH, KOH, Ca (OH) ₂ ; Alkali metal carbonates such as NaCO ₃ , LiCO ₃ , KCO ₃ , Ca (CO ₃ ) ₂ , NH ₄ CO ₃ ; Tertiary amine compounds such as trimethylamine, triethylamine, tripropylamine can be used. The tertiary amine compound, especially triethylamine, in the catalyst may be more preferably used in view of improving the efficiency of the aldol condensation reaction reaction.

The catalyst may be used in a molar ratio of 0.01 to 0.5, preferably 0.15 to 0.25, and more preferably 0.18 to 0.22, per mole of formaldehyde. That is, for the expression of the catalytic effect, the catalyst may be used in a molar ratio of 1: 0.01 or more relative to formaldehyde. However, if the catalyst is used excessively, recovery of the catalyst may be required and generation of by-products may be caused. Therefore, the catalyst is preferably used in a molar ratio of 1: 0.5 or less relative to formaldehyde.

On the other hand, in the aldol condensation reaction, the reaction temperature may be maintained at 70 to 100 ^° C, preferably 70 to 85 ^° C. In order to ensure the yield of the reaction, the reaction temperature is preferably 70 ^° C or more. However, when the reaction temperature is too high, the production of by-products may be accelerated, and the reaction temperature is preferably loo or lower. The aldol condensation reaction may be performed under pressure to ensure yield. The continuous production method of HPA performed under the above-described conditions enables the maximization of the mixing efficiency with respect to the raw material compound, thereby improving the efficiency of the aldol condensation reaction, and together with the remaining and byproducts of unreacted formaldehyde. The production can be minimized. Specifically, a high HPA yield of 99% or more and a low residual formaldehyde concentration of 2000 ppm or less can be secured through the continuous production method of HPA. 【Effects of the Invention】

The continuous production method of HPA according to the present invention enables the production of high yield HPA, and the HPA obtained through this can be suitably used for the synthesis of neopentyl glycol. [Brief Description of Drawings]

1 and 2 schematically show a method and a reaction system of continuous production of HPA according to one embodiment of the present invention, respectively.

[Explanation of code]

100: Aldol condensation reaction system

FO-iBAL: Isobutylaldehyde Supply Line

F0-FA: formaldehyde aqueous solution supply line

F0-TEA: catalyst supply line

SO: distributor

S1, S2, S3: Isobutylaldehyde Branch Input Line

R1, R2, R3: Continuous Stirring Reactor

CU: Circulation Unit

P: circulation pump

E: heat exchanger

V ： Semi-atomizer with Venturi nozzle

[Specific contents to carry out invention]

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are only intended to illustrate the present invention, and the invention is not limited thereto. Example 1

As shown in FIG. 1, an aldol condensation reaction system including three continuous stirring reactors (R1, R2 and R3) connected in series was prepared.

As a raw material compound for the production of HPA, an isobutyl aldehyde and an aqueous formaldehyde solution (containing an aldehyde concentration of 42% by weight ⁰ /., Containing 1% by weight ⁰ /. Triethylamine was prepared as a catalyst.

Formaldehyde: isobutylaldehyde: triethylamine was used in a molar ratio of 1: 1.1: 0.2. Formaldehyde aqueous solution and catalyst were added to the first reaction period. And, based on the total content of isobutyl aldehyde, 91 weight ⁰ /. Isobutyl aldehyde is in the first reaction period (R1), 7.5 weight ⁰ /. Isobutyl aldehyde is in the second reaction period (R2) ， 1.5 weight ⁰ /. Isobutylaldehyde was branched into the third reactor (R3), respectively. At the same time, the residence time of the reactants in each reactor was adjusted as shown in Table 1 below. And, the aldol condensation reaction was carried out continuously at a temperature of 72 to 78 ^° C and a pressure of 3 atm, the results are shown in Table 4 below.

Table 1

Example 2

In the same manner as in Example 1, except that an aldol condensation reaction system including three continuous stirring reactors R1, R2, and R3 connected in series through a semi-ungmul circulation unit (CU) as shown in FIG. 2 was used. Aldol condensation reaction was performed.

At this time, the semi-heated heat was removed through the heat exchanger E while circulating the semi-coated water to the outside of each of the semi-ungungers by operating the circulation pump P of each semi-coupling water circulation unit CU. And, the venturi provided in the reaction water injector (V) a part of the circulating reaction water Sprayed through the nozzle to the next reaction vessel.

The residence time of the reactants in each reactor was adjusted as shown in Table 2 below, and the results of the aldol condensation reaction were shown in Table 4 below. Table 2

Comparative Example 1

A quarter charge ratio of isobutyl aldehyde R1: R2: R3 = 91 weight ^_0/0: 5.97 wt. ^_0/0: 3.03 by weight was adjusted to ⁰ /, adjusted as the residence time banung water in each half unggi in the below table 3 Except for one, aldol condensation reaction was carried out in the same manner as in Example 1. The results are shown in Table 4 below.

Table 3

[Table 4]

Referring to Table 4, Comparative Example 1 showed a conversion rate equivalent to that of the examples, the concentration of residual formaldehyde in the product was found to be about 20% higher, and the yield of HPA was also lower. In contrast, the embodiment 1 and 2 showed a low concentration of residual formaldehyde as low as 2000 ppm and a high yield of HPA of 99% or more. In particular, Example 2 to which the reactant circulation unit was applied showed a high HPA yield of 99.80%.

Claims

[Claim]

[Claim 1 1

Obtaining a product containing hydroxyfibaldehyde through an aldol condensation reaction of an aqueous formaldehyde solution with isobutylaldehyde in the presence of a catalyst;

The isobutyl aldehyde is branched into each reaction at different ratios,

The reactants of the aldol condensation reaction are reacted under different residence times in each reaction vessel, hydroxyfibaldehyde.

[Claim 2]

The method of claim 1,

In the aldol condensation reaction, the ratio of isobutyl aldehyde branched into each reaction is sequentially reduced,

The residence time of the reaction product in each reaction system is sequentially increased, wherein the hydroxyfibaldehyde.

[Claim 3]

The method of claim 2,

The aldol condensation reaction is carried out in a series of three continuous stirred reaction reactor in series, hydroxyfibaldehyde.

[Claim 4]

The method of claim 3, wherein

Based on the total content of isobutylaldehyde added to the three continuous stirring reactors, isobutylaldehyde of 89 to 94% by weight is added to the first reactor and iso to 5 to 10% by weight of ⁰ /. Butylaldehyde is two 1 to 3 weight ⁰ /. Isobutyl aldehyde is added to the third reactor, the method of continuous production of hydroxyfibaldehyde.

[Claim 5]

The method of claim 3, wherein

The residence time of the reaction product in the three continuous stirring reactions is 10-13 minutes in the first reaction period, 13-17 minutes in the second reaction period and 17-19 minutes in the third reaction period. Process for Continuous Production of Aldehydes.

[Claim 6]

According to claim 1,

The aldol condensation reactions are carried out in three or more continuous stirring reactions, each connected in series via a reaction medium circulation unit;

The semi-ungmul circulation unit, a circulation pump for circulating a portion of the semi-ungmul in each reactor to the outside of the semi-ungunggi through the circulation pipe, a heat exchanger for removing the semi-heat heat from the reactants passing through the circulation pipe, and the circulation pipe And a reactant injector for spraying a portion of the reaction product to a next reaction vessel through a venturi nozzle.

[Claim 7]

The method of claim 6,

The aldol condensation reaction is carried out in three continuous stirred reactors each connected in series via the reaction mixture circulating oil;

The residence time of the reactants in the three continuous stirred reactors is 1 to 2 minutes in the first reactor, 1.5 to 5 minutes in the second reactor and 5 to 9 minutes in the third reactor, hydroxyfibaldehyde Continuous production process.