KR20210015178A - Preparing method of dimethylolbutanal and preperation method of trimethylolpropane using the same - Google Patents

Abstract

A method for preparing dimethylolbutanal according to one embodiment of the present application comprises the steps of: performing a first aldol reaction with n-butylaldehyde and a first formaldehyde under a first alkylamine catalyst to prepare a first active ingredient including dimethylol butanal and a by-product including ethyl acrolein; performing a distillation process to separate the by-product including the ethyl acrolein; and performing a second aldol reaction with the separated by-product including ethyl acrolein and a second formaldehyde under a second alkylamine catalyst to prepare a second active ingredient including dimethylol butanal.

Description

Method for producing dimethylolbutanal and method for producing trimethylolpropane using the same {PREPARING METHOD OF DIMETHYLOLBUTANAL AND PREPERATION METHOD OF TRIMETHYLOLPROPANE USING THE SAME}

The present application relates to a method for preparing dimethylolbutanal and a method for preparing trimethylolpropane using the same.

Trimethylolpropane (TMP) can be prepared in a variety of ways, one of which is Cannizzaro by converting n-butylaldehyde (n-BAL) and formaldehyde (FA) into an alkali metal (mainly NaOH) catalyst as follows. It is done through reaction.

The TMP production method by the Cannizzaro reaction, which is mainly used in the commercialization process, is not efficient because 1 mol of metal formate per mol of TMP is produced as a by-product.

Trimethylolpropane is a white crystalline substance at room temperature, and is widely used as a raw material in various fields such as alkyd resins, saturated polyesters, synthetic lubricants, polyurethane resins, and plasticizers. Therefore, research for producing trimethylolpropane, which is an industrially important raw material, in an economical manner has been continuously conducted.

U.S. Patent Registration Publication No. 3,956,306

The present application provides a method for preparing dimethylolbutanal and a method for preparing trimethylolpropane using the same.

An exemplary embodiment of the present application,

A first active ingredient comprising dimethylolbutanal (DMB) by performing a first aldol reaction with n-butylaldehyde (n-BAL) and a first formaldehyde (FA) under a first alkylamine catalyst And preparing a by-product including ethyl acrolein (EA);

Separating by-products including the ethyl acrolein by performing a distillation process; And

The step of preparing a second active ingredient including dimethylolbutanal (DMB) by performing a second aldol reaction with the separated ethyl acrolein-containing by-product and second formaldehyde under a second alkylamine catalyst. It provides a method for producing dimethylolbutanal containing.

In addition, another exemplary embodiment of the present application,

Preparing dimethylolbutanal according to the method for producing dimethylolbutanal; And

Hydrogenation reaction under a metal catalyst to prepare trimethylolpropane (TMP)

It provides a method for producing trimethylolpropane comprising a.

In the method for preparing dimethylolbutanal according to an exemplary embodiment of the present application, ethyl acrolein, a by-product generated after the aldol reaction of n-butylaldehyde (n-BAL) and formaldehyde, may be separated using a distillation process.

In particular, since ethyl acrolein separated using the distillation process can be used and dimethylolbutanal can be prepared by performing an additional aldol reaction, it is possible to increase the yield of the active ingredient including the prepared dimethylolbutanal. There are features.

In addition, trimethylolpropane can be obtained with high efficiency by using dimethylolbutanal prepared according to an exemplary embodiment of the present application as a raw material for a hydrogenation reaction.

Hereinafter, the present application will be described in more detail.

In the present application,'yield' is defined as a value obtained by dividing the amount of the product actually produced in the reaction by the maximum production amount that can be expected in theory.

In addition, in the present application, the'conversion rate (%)' refers to the rate at which the reactant is converted to a product, and for example, the n-BAL conversion rate may be defined by the following equation.

Conversion rate (%) = [(number of moles of reacted n-BAL)/(number of moles of supplied n-BAL)]×100

In the case of the Cannizzaro reaction to prepare TMP, the formate salt is also produced as a by-product as TMP is generated through the reaction of n-BAL. However, in the manufacturing method of trimethylolpropane according to an exemplary embodiment of the present application, since the DMB is separated by an extraction method after the aldol reaction, and then TMP is generated through a hydrogenation process, almost no by-products are generated.

The process of producing TMP by the hydrogenation method can be represented by the following reaction formula.

In the above reaction scheme, ethyl acrolein (EA) is a by-product produced after the aldol reaction of n-butylaldehyde (n-BAL) and formaldehyde, and conventionally, it has been separated and removed.

Accordingly, in the present application, the ethyl acrolein is separated and then recycled to improve the yield of active ingredients including dimethylolbutanal.

The method for preparing dimethylolbutanal according to an exemplary embodiment of the present application is to perform a first aldol reaction under a first alkylamine catalyst with n-butylaldehyde (n-BAL) and a first formaldehyde (FA). , Preparing a by-product including a first active ingredient and ethyl acrolein (EA) containing dimethylolbutanal (DMB, dimethylolbutanal); Separating by-products including the ethyl acrolein by performing a distillation process; And performing a second aldol reaction of the separated ethyl acrolein-containing by-product and second formaldehyde under a second alkylamine catalyst to prepare a second active ingredient including dimethylolbutanal (DMB). Includes.

In the exemplary embodiment of the present application, the reactor in which the first aldol reaction and the second aldol reaction are performed is not particularly limited if the reactor can be used for the aldol reaction. For example, the reactor may be a jacket type reactor, but is not limited thereto.

In the exemplary embodiment of the present application, in the process of reacting the first aldol, n-butylaldehyde, the first formaldehyde, and the first alkylamine catalyst may be simultaneously introduced into the reactor, some of which are first introduced into the reactor. It could be. For example, in order to further improve the reaction efficiency, it is preferable to first introduce n-butylaldehyde and first formaldehyde into the reactor, and then slowly introduce the first alkylamine catalyst into the reactor. In addition, the step of stirring after the n-butylaldehyde, the first formaldehyde and the first alkylamine catalyst are added to the reactor may be further included. In addition, after the n-butylaldehyde, the first formaldehyde, and the first alkylamine catalyst are added to a reactor, a step of stirring simultaneously with the reaction may be performed. That is, the reaction and stirring can be performed simultaneously. The stirring speed of the stirring step may be 150rpm to 350rpm, more preferably 200rpm to 300rpm.

In the exemplary embodiment of the present application, when the first aldol reaction is performed, the molar ratio of the n-butylaldehyde: the first formaldehyde may be 1: (3 ~ 5), and 1: (3.5 ~ 4.5). have. When the first aldol reaction is carried out, when the molar ratio of the first formaldehyde to the n-butyl aldehyde is less than 3, the n-BAL conversion rate decreases, and the by-product after the distillation process for separating the by-product including ethyl acrolein n -BAL rate may increase. In this case, since the content of the second formaldehyde for performing the second aldol reaction must be increased, additional processing costs may occur. In addition, when the first aldol reaction is performed, when the molar ratio of the first formaldehyde to the n-butyl aldehyde exceeds 5, the by-product EA is generated less and the yield of the active ingredient may increase, but the first form The energy and cost of the formaldehyde treatment process can be increased due to the excessive use of aldehydes.

In the exemplary embodiment of the present application, the molar ratio of the n-butylaldehyde: the first alkylamine catalyst may be 1: (0.1 ~ 0.3), and 1: (0.1 ~ 0.2). When the first alkylamine catalyst is less than 0.1 mol based on 1 mol of n-butylaldehyde, the reaction rate may be slowed to increase the reaction time, and when it exceeds 0.3 mol, a large amount of catalyst is used, so economical efficiency is achieved. It can fall.

In the exemplary embodiment of the present application, the first aldol reaction may be performed at a temperature of 50°C to 90°C, and may be performed at a temperature of 60°C to 80°C. When the temperature of the aldol reaction process is less than 50° C., the conversion rate decreases and the reaction rate becomes slow, so that the total reaction time may increase. In addition, when the temperature of the aldol reaction process exceeds 90° C., the yield may decrease, and economy due to the use of excessive energy may decrease.

In the exemplary embodiment of the present application, the first alkylamine catalyst and the second alkylamine catalyst may each include an alkylamine having 3 to 20 carbon atoms. More specifically, the first alkylamine catalyst and the second alkylamine catalyst are one of trimethylamine, triethylamine (TEA), tripropylamine, and diisopropylethylamine, respectively. It may contain more than a species, and preferably may contain triethylamine.

An exemplary embodiment of the present application includes the step of separating the by-product including the ethyl acrolein by performing a distillation process. The by-product may further include water in addition to ethyl acrolein.

In the exemplary embodiment of the present application, the distillation process may be performed at a temperature condition of 40°C to 60°C, and may be performed at a temperature condition of 45°C to 55°C. When the temperature condition of the distillation process is satisfied, the ratio of ethyl acrolein in the by-product can be maximized during the distillation process for separating the by-product including ethyl acrolein.

In addition, the distillation process may be performed under a pressure condition of more than 120 mbar and less than 230 mbar, and may be performed under a pressure condition of 150 mbar to 210 mbar. When the pressure condition of the distillation process is less than 120mbar, H ₂ O may be distilled excessively and heavy components may be distilled, so that the content of ethyl acrolein in the by-product may be low. In addition, when the pressure condition of the distillation process is 230 mbar or more, the total amount of distillation may be small.

An exemplary embodiment of the present application is to perform a second aldol reaction with the separated ethyl acrolein-containing by-product and second formaldehyde under a second alkylamine catalyst, and thus a second product containing dimethylolbutanal (DMB). 2 It includes the step of preparing an active ingredient.

In an exemplary embodiment of the present application, when performing the second aldol reaction, the molar ratio of the ethyl acrolein: second formaldehyde: second alkylamine catalyst may be 1: (10 ~ 15): (0.05 ~ 0.5), and , 1: (10 ~ 13): can be (0.05 ~ 0.3). In particular, when the molar ratio of the second formaldehyde based on the ethyl acrolein is less than 10, the yield of the active ingredient may decrease, and when it exceeds 15, the yield of the active ingredient no longer increases, so the raw material cost increases. I can.

In the exemplary embodiment of the present application, the second aldol reaction may be performed under a temperature condition of 30°C to 40°C, and may be performed under a temperature condition of 32°C to 38°C. When the temperature condition of the second aldol reaction is less than 30°C, the reaction rate may decrease, and when it exceeds 40°C, the yield of the active ingredient no longer increases, which is not preferable in terms of energy saving.

In the exemplary embodiment of the present application, after performing the second aldol reaction, the step of injecting the second active ingredient into the first active ingredient after the by-product is separated may be further included.

In addition, after the step of injecting the second active ingredient into the first active ingredient after the by-product is separated, the step of separating the dimethylolbutanal by performing an extraction process using an alcohol solvent may be further included. I can.

The alcohol solvent may be an alcohol solvent having 2 to 10 carbon atoms. Specifically, the alcohol solvent may be an alcohol solvent having 6 to 8 carbon atoms, preferably an alcohol solvent having 8 carbon atoms. In the exemplary embodiment of the present specification, the alcohol solvent may be 2-ethylhexanol (2-EH).

In the exemplary embodiment of the present application, the total weight of the first active ingredient and the second active ingredient: the weight ratio of the alcohol solvent may be 1: (0.3 ~ 1.5), and 1: (0.5 ~ 1.3). If the weight ratio of the alcohol solvent is less than 0.3, the extraction efficiency may decrease, and if it exceeds 1.5, the extraction efficiency may increase, but since the amount of the solvent increases, the cost of treating the used solvent increases. Not.

In an exemplary embodiment of the present application, the extraction temperature in the extracting step is preferably 25°C to 90°C, and specifically, 30°C to 70°C. When the extraction temperature is satisfied, the extraction yield can be increased.

In the method for producing dimethylolbutanal according to an exemplary embodiment of the present application, the yield of the active ingredient including monomethylolbutanal (MMB), dimethylolbutanal (DMB) and TMP that is finally prepared is 95% or more. Can be, and can be more than 97%.

In addition, a method for producing trimethylolpropane according to an exemplary embodiment of the present application includes the steps of preparing dimethylolbutanal according to the method for producing dimethylolbutanal; And hydrogenation reaction under a metal catalyst to produce trimethylolpropane (TMP).

In the exemplary embodiment of the present application, the metal catalyst may be a copper-based metal catalyst. The copper-based metal catalyst is not limited as long as it is a catalyst used in the hydrogenation reaction.

In the exemplary embodiment of the present application, the reactor used in the method for producing trimethylolpropane may be a batch type hydrogenation reactor, but is not limited thereto.

In an exemplary embodiment of the present application, the reaction temperature of the hydrogenation reaction may be 80°C to 150°C, preferably 100°C to 140°C, and more preferably 110°C to 130°C. The reaction pressure of the hydrogenation reaction may be 20 bar to 70 bar. Preferably it may be from 25 bar to 50 bar. When the reaction temperature and the reaction pressure of the hydrogenation reaction satisfy the above-described range, trimethylolpropane can be prepared in a high yield.

In the exemplary embodiment of the present application, in the hydrogenation reaction, the molar ratio of hydrogen (H ₂ ) based on 1 mole of dimethylolbutanal may be 1 to 3, preferably 1 to 2.

In the exemplary embodiment of the present application, in the step of preparing trimethylolpropane, trimethylolpropane may be prepared in a yield of 70% or more, and may be prepared in a yield of 75% or more.

In the exemplary embodiment of the present application, the method for producing trimethylolpropane may further include preparing trimethylolpropane by hydrogenation and then purifying it.

Hereinafter, in order to describe the present application in detail, an experimental example will be described in detail. However, the experimental examples according to the present application may be modified in various different forms, and the scope of the present application is not interpreted as being limited to the experimental examples described below. Experimental examples of the present application are provided to more completely describe the present application to those of ordinary skill in the art.

< Experimental example >

< Experimental example 1>

1) first Aldol reaction

After adding 100 g of n-BAL (n-butylaldehyde) and 400 g of 42% formalin (n-BAL: FA molar ratio is 1: 4) into a 1L reactor capable of temperature control, 15 g of TEA as a base catalyst is slowly added dropwise. To start the reaction. At this time, the reaction temperature was adjusted to 70 ℃.

After about 3 hours, the reaction product was sampled, GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reaction product and calculate the conversion rate and yield.

2) Distillation process

The temperature inside the reactor was lowered to 50° C. and reduced to 150 mbar to perform a distillation process. After the completion of the distillation process, the light components were sampled, and GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reactants.

3) second Aldol reaction

After confirming the composition of the light component, the molar ratio of EA: FA: TEA was adjusted to a ratio of 1: 10: 0.1, and the aldol reaction was additionally performed. At this time, the reaction temperature was adjusted to 35 ℃.

After about 3 hours, the reaction was stopped, and the reaction product was sampled to perform GC analysis, FA analysis, and moisture analysis, to confirm the composition of the reaction product, and calculate the total conversion and yield.

< Experimental example 2>

In Experimental Example 1, it was carried out in the same manner as in Experimental Example 1, except that the distillation process was performed by reducing the pressure to 180 mbar during the distillation process.

< Experimental example 3>

In Experimental Example 1, during the distillation process, the distillation process was performed by reducing the pressure to 120 mbar. As shown in Table 1 below, after the distillation process was completed, the content of EA in the light component was 67.0% by weight, and the content was small, so the second aldol reaction was not performed.

< Experimental example 4>

In Experimental Example 1, during the distillation process, the distillation process was performed by reducing the pressure to 230 mbar. As shown in Table 1 below, after the distillation process was completed, the content of EA in the light component was 76.2% by weight, which was low, so the second aldol reaction was not performed.

< Experimental example 5>

In Experimental Example 2, the second aldol reaction was carried out in the same manner as in Experimental Example 1, except that the molar ratio of EA: FA: TEA was adjusted to a ratio of 1:4:0.1.

< Experimental example 6>

After adding 100 g of n-BAL (n-butylaldehyde) and 400 g of 42% formalin (n-BAL: FA molar ratio is 1: 4) into a 1L reactor capable of temperature control, 15 g of TEA as a base catalyst is slowly added dropwise. To start the reaction. At this time, the reaction temperature was adjusted to 70 ℃.

After about 3 hours, the reaction product was sampled, GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reaction product and calculate the conversion rate and yield.

< Experimental example 7>

1) first Aldol reaction

After adding 100 g of n-BAL (n-butylaldehyde) and 200 g of 42% formalin (n-BAL: FA molar ratio is 1: 2) to a 1L reactor capable of temperature control, 15 g of TEA as a base catalyst is slowly added dropwise To start the reaction. At this time, the reaction temperature was adjusted to 70 ℃.

After about 3 hours, the reaction product was sampled, GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reaction product and calculate the conversion rate and yield.

2) Phase separation process

After lowering the internal temperature of the reactor to room temperature, the organic solution layer was separated from the two separated layers. By sampling, GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reactants.

< Experimental example 8>

1) first Aldol reaction

After adding 100 g of n-BAL (n-butylaldehyde) and 200 g of 42% formalin (n-BAL: FA molar ratio is 1: 2) to a 1L reactor capable of temperature control, 15 g of TEA as a base catalyst is slowly added dropwise. To start the reaction. At this time, the reaction temperature was adjusted to 70 ℃.

After about 3 hours, the reaction product was sampled, GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reaction product and calculate the conversion rate and yield.

2) Distillation process

The temperature inside the reactor was lowered to 50° C., and the pressure was reduced to 180 mbar to perform a distillation process. After the completion of the distillation process, the light components were sampled, and GC analysis, FA analysis, and moisture analysis were performed to confirm the composition of the reactants.

Samples were collected in the middle of the reaction of Experimental Examples 1 to 8 and after completion of the reaction to perform moisture analysis, FA analysis, and gas chromatography (GC) analysis. The content of each component was calculated as 100% including H ₂ O and FA after applying the factor of GC. The moisture content (% by weight) in the solution is analyzed using a Karl-fischer titrator (Metrohm, 870KF Titrino plus), and the FA content (% by weight) in the solution includes GC-TCD (Youngrin, ACME6100), including DMB and TMP. The content of organic matter was analyzed using GC-FID (Agilent, 7890).

[Table 1]

The n-BAL conversion rate and the active ingredient yield of the first Aldol process were calculated from Equations 1 and 2, respectively.

[Equation 1]

n-BAL conversion rate (%) = [(n-BAL moles before reaction-n-BAL moles after reaction) / n-BAL moles before reaction] × 100

[Equation 2]

Active ingredient yield (%) = [Total number of moles after reaction (MMB + DMB + TMP) / number of n-BAL moles before reaction] × 100

In addition, the EA conversion rate and the active ingredient yield of the second Aldol process were calculated from Equations 3 and 4, respectively.

[Equation 3]

EA conversion rate (%) = [(Number of moles of EA before reaction-Number of moles of EA after reaction) / Number of moles of EA before reaction] × 100

[Equation 4]

Active ingredient yield (%) = [Total moles after reaction (MMB + DMB + TMP) / EA moles before reaction] × 100

When comparing the results of Experimental Examples 1 to 2 and Experimental Example 6, the method for preparing dimethylolbutanal according to an exemplary embodiment of the present application is after the aldol reaction of n-butylaldehyde (n-BAL) and formaldehyde. It can be seen that ethyl acrolein, a by-product produced, can be separated using a distillation process. In particular, since ethyl acrolein separated using the distillation process can be used and dimethylolbutanal can be prepared by performing an additional aldol reaction, it is possible to increase the yield of the active ingredient including the prepared dimethylolbutanal. There are features.

In addition, when comparing the results of Experimental Examples 1 to 2 and Experimental Example 5, when performing the second aldol reaction, the molar ratio of the ethyl acrolein: second formaldehyde: second alkylamine catalyst was 1: (10 to 15) : When (0.05 ~ 0.5), it can be confirmed that there is a characteristic that can further increase the yield of the active ingredient.

In addition, when comparing the results of Experimental Examples 1 to 2 and Experimental Examples 3 to 4, when the distillation process is performed under a pressure condition of more than 120 mbar and less than 230 mbar, the content of ethyl acrolein in the by-product is high, and the total amount of distillation is Since there are many, it can be seen that a more effective distillation process can be performed.

In addition, when comparing the results of Experimental Examples 1 to 2 and Experimental Examples 7 to 8, when the first aldol reaction is performed, the molar ratio of the n-butylaldehyde: first formaldehyde is 1: (3 to 5) It can be seen that the n-BAL conversion rate of the first aldol process is high, and thus the yield of the active ingredient is increased.

In addition, in Experimental Examples 3 to 4 and 7 to 8, it was difficult to perform the second aldol process because the EA content in the light component after the distillation process or the phase separation process was low.

As described above, in the method for preparing dimethylolbutanal according to an exemplary embodiment of the present application, ethyl acrolein, a by-product produced after the aldol reaction of n-butylaldehyde (n-BAL) and formaldehyde, is distilled using a distillation process. Can be separated.

In particular, since ethyl acrolein separated using the distillation process can be used and dimethylolbutanal can be prepared by performing an additional aldol reaction, it is possible to increase the yield of the active ingredient including the prepared dimethylolbutanal. There are features.

In addition, trimethylolpropane can be obtained with high efficiency by using dimethylolbutanal prepared according to an exemplary embodiment of the present application as a raw material for a hydrogenation reaction.

Claims (10)

A first active ingredient comprising dimethylolbutanal (DMB) by performing a first aldol reaction with n-butylaldehyde (n-BAL) and a first formaldehyde (FA) under a first alkylamine catalyst And preparing a by-product including ethyl acrolein (EA);
Separating the by-product including the ethyl acrolein by performing a distillation process; And
The step of preparing a second active ingredient including dimethylolbutanal (DMB) by performing a second aldol reaction with the separated ethyl acrolein-containing by-product and second formaldehyde under a second alkylamine catalyst. The method for producing dimethylolbutanal containing. The method of claim 1, wherein when performing the first aldol reaction,
The n-butylaldehyde: the molar ratio of the first formaldehyde is 1: (3 ~ 5) is a method for producing dimethylolbutanal. The method of claim 1, wherein when performing the first aldol reaction,
The n-butylaldehyde: the molar ratio of the first alkylamine catalyst is 1: (0.1 ~ 0.3) of the method for producing dimethylolbutanal. The method of claim 1, wherein the first aldol reaction is performed under a temperature condition of 50°C to 90°C. The method of claim 1, wherein the distillation process is performed under a temperature condition of 40°C to 60°C and a pressure condition of more than 120mbar and less than 230mbar. The method according to claim 1, when performing the second aldol reaction,
The ethyl acrolein: second formaldehyde: second alkylamine catalyst has a molar ratio of 1: (10 ~ 15): (0.05 ~ 0.5) of the method for producing dimethylolbutanal. The method of claim 1, wherein the second aldol reaction is performed under a temperature condition of 30°C to 40°C. The method according to claim 1, after performing the second aldol reaction,
The method for producing dimethylolbutanal further comprising the step of adding the second active ingredient to the first active ingredient after the by-product is separated. The method of claim 8, further comprising the step of separating the dimethylolbutanal by performing an extraction process using an alcohol solvent. Producing dimethylolbutanal according to the method for producing dimethylolbutanal of any one of claims 1 to 9; And
Hydrogenation reaction under a metal catalyst to prepare trimethylolpropane (TMP)
The method for producing trimethylolpropane comprising a.