KR20180047257A - Trimethylolpropane manufacturing device and method using thereof - Google Patents

Abstract

The present invention relates to a trimethylolpropane manufacturing device and a manufacturing method using the same. More specifically, the trimethylolpropane manufacturing device includes: an aldol reactor (a) generating 2,2-dimethylolbutanal (DMB) by making an aldol reaction between n-butyric aldehyde and formaldehyde under the existence of an amine compound as a catalyst; a moisture and formaldehyde pre-remover (b) removing some or the entire moisture and formaldehyde from the aldol reaction product including the DMB; an hydrogenation reactor (c) generating trimethylolpropane (TMP) by conducting hydrogenation to the DMB from which moisture and formaldehyde are removed; and a purifier (d) purifying the TMP. According to the present invention, moisture and formaldehyde are removed from the aldol reaction product including the DMB, the removed moisture and formaldehyde are reused for an aldol reaction, and the need for conventional extraction and organic solvent purification processes is eliminated, and thus, the present invention is capable of simplifying processes and reducing energy consumption.

Description

TECHNICAL FIELD [0001] The present invention relates to an apparatus for producing trimethylolpropane and a method for producing the same,

The present invention relates to an apparatus for producing trimethylolpropane and a process for producing the same, and more particularly to a process for producing trimethylolpropane by removing moisture and formaldehyde from a product after aldol reaction, reusing the removed water and formaldehyde for aldol reaction, And an organic solvent purification process are not required, thereby simplifying the process and reducing the amount of energy used, and a manufacturing method using the same.

Trimethylolpropane (TMP) is a white crystalline material at room temperature and is widely used as raw material in various fields such as alkyd resin, saturated polyester, synthetic lubricating oil, polyurethane resin and plasticizer field. Therefore, studies for producing trimethylolpropane, which is an industrially important raw material, in an economical manner have been continuously carried out.

Industrial production of trimethylolpropane (TMP) uses n-butyraldehyde and formaldehyde as starting materials. In general, first, 2,2-dimethylol butane is formed through intermediate 2-methylol butane in a base-catalyzed reaction, and trimethylol propane is added simultaneously with the free of calcium formate in the presence of calcium hydroxide . However, the process is carried out as a one-step process, which has the disadvantage that it can not individually optimize the individual reaction steps, i.e. the steps of forming 2,2-dimethylol butane and its conversion to trimethylolpropane. This has the problem that the yield based on the formation of undesirable by-products and the n-butyraldehyde used is unsatisfactory.

To avoid this disadvantage, a two-step process has been developed in which the 2,2-dimethylolbutane aldehyde is prepared from n-butyraldehyde and formaldehyde by condensation reaction in the first stage followed by hydrogenation thereof in the second stage.

DE-A 25 07 461 is obtained, for example, from n-butyraldehyde and formaldehyde in the presence of a catalytic amount of tert-trialkylamine in which the 2,2-dimethylolbutanal contains at least one branched alkyl radical The following two-step process of hydrogenation is described. The yield of trimethylolpropane of about 75% based on the n-butyraldehyde used can be obtained but is not a satisfactory level.

According to DE-A 196 53 093, in the first stage, the preparation of 2,2-dimethylol butane is carried out by condensation reaction of n-butyraldehyde and formaldehyde in the presence of a catalytic amount of tert- When the unreacted starting material and the formed by-products which are carried out and are reacted further are recycled, the yield of trimethylolpropane based on the used n-butyraldehyde and formaldehyde can be remarkably increased. In the second step, the condensation product (2,2-dimethylolbutane) obtained in this manner is hydrogenated with trimethylolpropane.

EP-A 860 419 also discloses that the first stage of the production of 2,2-dimethylol butane from n-butyraldehyde and formaldehyde, that is, the first stage of the production of trimethylolpropane, takes place in one stage and in the second stage Ethyl acrolein formed as a by-product is reacted with additional formaldehyde in a plurality of stages. The 2,2-dimethylol butane produced in this manner can be hydrogenated in the second step to give trimethylol propane.

This process of producing trimethylol propane in two steps, i.e., the step of preparing 2,2-dimethylol butane and the step of preparing trimethylol propane, can be carried out in such a manner that the two steps can be individually optimized and thus an excellent yield can be obtained There is a disadvantage that energy is consumed a lot due to the process of removing water during the above processes and the price competitiveness is lowered.

In the above-mentioned conventional process, trimethylol propane (TMP) is obtained through a hydrogenation reaction (hereinafter, referred to as a 'hydrogenation reaction') after extracting the DMB produced by the aldol reaction with a solvent, followed by distillation and purification. Therefore, a large amount of solvent is required as an extraction agent, a separation / recovery device for starting formaldehyde is additionally needed, and there is a problem that loss of product DMB is small.

In order to solve the problems of the prior art as described above, the present invention provides a method of extracting 2,2-dimethylolbutanal (DMB) by maximally removing water and formaldehyde in the aldol reaction product, The present invention aims at providing an apparatus for producing trimethylolpropane and a method of using the same, in which an organic solvent required for an organic solvent is not required and an additional formaldehyde separation and recovery process is not required, thereby simplifying the process and reducing energy consumption for the entire process.

These and other objects of the present disclosure can be achieved by all of the present invention described below.

In order to accomplish the above object, the present invention provides an aldol reaction apparatus comprising: a) an aldol reactor in which n-butyraldehyde and formaldehyde are subjected to aldol reaction in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylolbutanal); b) a water and formaldehyde line remover which removes some or all of water and formaldehyde from the aldol reaction product comprising the DMB; c) a hydrogenation reactor for producing TMP (trimethylol propane) by hydrogenation of the water and formaldehyde-removed DMB; And d) a purifying apparatus for purifying the TMP. The present invention also provides an apparatus for producing trimethylolpropane.

Also, the present invention provides a method for producing a polyisocyanate compound, which comprises: 1) aldol reaction of n-butyraldehyde and formaldehyde in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylolbutanal); 2) removing some or all of water and formaldehyde from the aldol reaction product comprising the DMB of step 1); 3) hydrolyzing DMB in which water and formaldehyde are removed in step 2) to produce TMP (trimethylol propane); And 4) distilling the product obtained in the step 3) to remove low boiling point impurities and high boiling point impurities and purifying them.

According to the present invention, since the extraction efficiency of DMB (2,2-dimethylol butane) is maximized by removing water and formaldehyde in the aldol reaction product in advance, an organic solvent required for DMB extraction is not required and separation of additional formaldehyde And the recovery process is not required, thereby simplifying the process and reducing the energy consumption for the entire process.

FIG. 1 shows a conventional apparatus for producing trimethylolpropane, in which DMB is produced by aldol reaction of n-butyraldehyde and formaldehyde, and then TMP is produced by extracting and concentrating the resultant by hydrogenation and purifying TMP by a distillation tower. Fig.
FIG. 2 is a graph showing the results obtained by removing part of water and formaldehyde from the aldol reaction product of n-butyraldehyde and formaldehyde according to the present invention using water and a formaldehyde eliminator, In which the TMP is purified by the method of the present invention.
3 is a process diagram briefly showing a manufacturing process of a conventional TMP.
4 is a process drawing briefly showing a manufacturing process of the TMP according to the present invention.

Hereinafter, an apparatus for producing trimethylolpropane according to the present invention will be described in detail.

An apparatus for producing trimethylolpropane according to the present invention comprises: a) an aldol reactor in which n-butyraldehyde and formaldehyde are subjected to aldol reaction in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylol butane); b) a water and formaldehyde line remover which removes some or all of water and formaldehyde from the aldol reaction product comprising the DMB; c) a hydrogenation reactor for producing TMP (trimethylol propane) by hydrogenation of the water and formaldehyde-removed DMB; And d) a purification apparatus for purifying the TMP.

The amine compound in the aldol reactor a) may be, for example, trimethylamine, triethylamine or a mixture thereof. In this case, the formation of by-products is suppressed and the DMB production efficiency is excellent.

The amine compound in the aldol reactor a) may be used in an amount of 0.01 to 0.5 mol, 0.02 to 0.1 mol, or 0.03 to 0.08 mol per mol of n-butyraldehyde, for example. In this range, There is an effect to be generated.

In the a) aldol reactor, the formaldehyde may be in the form of an aqueous solution containing from 1 to 50% by weight, from 20 to 40% by weight, or from 30 to 37% by weight of formaldehyde, It has excellent effect.

In the a) aldol reactor, n-butyraldehyde and formaldehyde can be, for example, in a molar ratio of 1: 2 to 1:19, 1: 2 to 1: 5, or 1: 2 to 1: 3, The DMB generation efficiency is excellent.

The aldol reaction in the aldol reactor a) may be carried out at a reaction temperature of 5 to 100 ° C, 15 to 80 ° C, or 20 to 60 ° C, for example. And a reaction time of 20 minutes to 12 hours, 1 to 6 hours, or 2 to 4 hours, and the reaction efficiency is excellent in this range.

The b) water and formaldehyde line remover may be combined with a transfer line for transferring the removed moisture and formaldehyde to the aldol reactor, which is unlike the prior art, and an additional purification process is required for reuse of formaldehyde Since it is not necessary, it is not only excellent in energy efficiency and economical efficiency, but also can remove water and formaldehyde, which have been removed beforehand, directly to the aldol reactor, thus being advantageous in process simplification and economical efficiency.

The pre-removed moisture and formaldehyde may be, for example, an aqueous solution containing 1 to 37% by weight, or 10 to 37% by weight of formaldehyde.

The b) moisture and formaldehyde line remover may be, for example, 10 to 99 wt%, 50 to 99 wt%, 85 to 98 wt%, or 85 to 95 wt% in 100 wt% of water in the aldol reaction product containing DMB And the extractor and the organic solvent purifier are not required within this range, so that the process is simplified and the heat required to remove moisture from the downstream is reduced, thereby reducing energy consumption.

The b) moisture and formaldehyde line remover may be, for example, 10 to 100%, 50 to 100%, 70 to 100%, or 80 to 99% by weight in 100% by weight of formaldehyde in the aldol reaction product comprising DMB, And the extractor and the organic solvent purifier are not required within the range, so that the process is simplified and the energy consumption is reduced.

The b) water and formaldehyde line eliminator may include a flash drum. In this case, the process is simple and the loss of the product DMB is small, and water and low-boiling impurities such as formaldehyde are effectively removed .

Wherein the flash drum has a temperature of 75 to 115 캜, 80 to 110 캜, or 85 to 105 캜; And a pressure of 250 to 550 mmHg, 300 to 500 mmHg, or 350 to 450 mmHg; , And there is an effect that the loss of product is small while efficiently removing water within this range.

In the c) hydrogenation reactor, TMP (trimethylol propane) is prepared by adding hydrogen to a DMB solution in which water and formaldehyde are partially or wholly removed.

The d) hydrogenation reactor may include, for example, a hydrogenation catalyst and is not particularly limited in the case of a hydrogenation catalyst capable of hydrogenating an aldehyde with an alcohol.

The d) refining apparatus includes, for example, i) a low boiling point removal tower for removing low boiling point impurities from the TMP produced by the hydrogenation reaction, and ii) a high boiling point removal tower for removing high boiling point impurities from the TMP from which the low boiling point impurities have been removed In this case, it is possible to obtain a high purity TMP.

The i) low boiling point impurities in the i) low boiling point column are discharged through the upper pipe and the remaining material including TMP is transferred to the high boiling point removal tower through the lower pipe.

For example, in the above-mentioned (ii) high boiling point removing column, the high boiling point impurity is discharged to the lower pipe, and the TMP is obtained through the upper pipe.

The low boiling point impurity in the above d) refining apparatus is a substance having a boiling point lower than that of TMP, for example, water, methanol, or an amine compound.

The d) high boiling point impurity in the purification apparatus refers to a substance having a boiling point higher than that of TMP, and may be, for example, a by-product of the aldol reaction.

The i) low boiling point removal tower may for example have a pressure of 35 to 65 mmHg, 40 to 60 mmHg, or 45 to 55 mmHg; A top temperature of 100 to 135 占 폚, 105 to 125 占 폚, or 107 to 121 占 폚; And a bottom temperature of 215 to 240 캜, 220 to 235 캜, or 225 to 230 캜; And the effect of purifying the low-boiling point impurity is excellent within this range.

The ii) high boiling point removal tower may have a pressure of, for example, 10 to 30 mmHg, 15 to 25 mmHg, or 18 to 23 mmHg; A top temperature of 180 to 210 占 폚, 190 to 200 占 폚, or 190 to 195 占 폚; And a bottom temperature of 230 to 260 캜, 240 to 255 캜, or 243 to 248 캜; And the effect of purifying the high boiling point impurities within this range is excellent.

The above apparatus for producing trimethylolpropane does not require an extractor for extracting an aldol reaction product with an organic solvent and an organic solvent purifier for removing an organic solvent, so that the process is simplified and compared to a conventional apparatus including an extractor and an organic solvent purifier The energy saving effect is excellent.

The process for producing trimethylolpropane according to the present invention comprises the steps of 1) aldol reaction of n-butyraldehyde and formaldehyde in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylol butane); 2) removing some or all of water and formaldehyde from the aldol reaction product comprising the DMB of step 1); 3) hydrolyzing DMB in which water and formaldehyde are removed in step 2) to produce TMP (trimethylol propane); And 4) distilling the product obtained in the step 3) to remove and purify the low boiling point impurities and high boiling point impurities.

The amine compound in step 1) may be, for example, trimethylamine, triethylamine or a mixture thereof. In this case, the DMB production efficiency is excellent.

The moisture and formaldehyde removed from the DMB in the step 2) can be transferred to the step 1) and reused, in which case the additional formaldehyde separation and recovery step is not necessary.

In the step 2), 10 to 99% by weight, 50 to 99% by weight, 80 to 98% by weight, or 85 to 95% by weight of water may be removed from the aldol reaction product containing DMB In this range, there is no need for extraction and organic solvent purification steps, which simplifies the process and reduces the heat required to remove moisture from the rear end, thereby reducing energy consumption.

In step 2), 10 to 100% by weight, 50 to 100% by weight, 70 to 100% by weight, or 80 to 99% by weight of formaldehyde is removed from 100% by weight of the total formaldehyde And the extraction step and the organic solvent purification step are not required within this range, so that the process is simplified and the energy consumption is reduced.

The aldol reaction product containing DMB in the step 2) may be, for example, at a temperature of from 75 to 115 ° C, from 80 to 110 ° C, or from 85 to 105 ° C in a flash drum; A pressure of 250 to 550 mmHg, a pressure of 300 to 500 mmHg, or a pressure of 350 to 450 mmHg; and the product loss is effectively reduced while efficiently removing water within this range. The water removal rate can be adjusted by adjusting the temperature of the flash drum.

In the step 3), the residual formaldehyde is converted into methanol in the step of producing trimethylolpropane (TMP) by subjecting the DMB obtained by removing part or all of water and formaldehyde from the step 2) to hydrogenation, It can be separated into low boiling point impurities.

Removal of the low boiling point impurities in step 4) may be performed, for example, through a low boiling point removal column at a pressure of 35 to 65 mmHg, 40 to 60 mmHg, or 45 to 55 mmHg; A top temperature of 100 to 135 占 폚, 105 to 125 占 폚, or 107 to 121 占 폚; And a bottom temperature of 215 to 240 캜, 220 to 235 캜, or 225 to 230 캜; , And the effect of purifying the low-boiling point impurity is excellent within this range.

The low boiling point impurity is a material having a lower boiling point than TMP, and may be, for example, water, methanol, or an amine compound.

Removal of the high boiling point impurities in step 4) may, for example, be performed at a pressure of 10 to 30 mmHg, 15 to 25 mmHg, or 18 to 23 mmHg; A top temperature of 180 to 210 占 폚, 190 to 200 占 폚, or 190 to 195 占 폚; And a bottom temperature of 230 to 260 캜, 240 to 255 캜, or 243 to 248 캜; And the effect of purifying high boiling point impurities within this range is excellent.

The high boiling point impurity is a substance having a boiling point higher than that of TMP, and may be, for example, a by-product of the aldol reaction.

For example, purified TMP is obtained by first removing low boiling point impurities from the crude TMP product through a low boiling point removal column, and then removing high boiling point impurities again through a high boiling point removal column.

In the present description, the removal column may be, for example, a distillation column.

The method of producing trimethylolpropane according to the present invention is not limited to the steps of extracting DMB with an organic solvent and purifying the organic solvent, so that the manufacturing steps are simple and the flash drum is used instead of a multi-stage device, The effect to be saved is excellent.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[Example]

Example  One

(B: F) at a molar ratio (B: F) of 1: 2 was fed to a reactor equipped with the apparatus shown in Fig. 2 at a ratio of 0.03 mol of TEA per 1 mol of n-butyraldehyde as a catalyst And the aldol reaction was carried out in an aldol reactor at a temperature of 50 ° C for 2 hours. The aldol reaction product was removed from water and formaldehyde line remover at a temperature of 87 캜 and a pressure of 400 mmHg under the conditions shown in Table 1 below to remove 85% by weight of moisture and 96% by weight of formaldehyde. (DMB solution) discharged to the lower portion of the line remover was transferred to a hydrogenation reactor and hydrogenated to produce Crude TMP. The resulting product was passed through a low boiling point eliminating column and a high boiling point eliminating column under the conditions shown in Table 1 below, Gt; TMP < / RTI >

 At this time, the obtained TMP had a 97.5% recovery of TMP against the added n-butyraldehyde and a purity of 99.99% or more.

The total energy consumption according to the process was 4.63 Gcal / hr.

Example  2

In Example 1, 90% by weight of moisture and 97% by weight of formaldehyde were removed from the upper part under conditions of the temperature of 91 ° C and the pressure of 400 mmHg in the condition of Table 1 in the moisture and alcohol eliminator. (DMB solution) discharged to the lower portion of the line remover was transferred to a hydrogenation reactor and hydrogenated to produce Crude TMP. The resulting product was passed through a low boiling point eliminating column and a high boiling point eliminating column under the conditions shown in Table 1 below, Gt; TMP < / RTI > was obtained, respectively.

At this time, the obtained TMP had a 97.5% recovery of TMP against the added n-butyraldehyde and a purity of 99.99% or more.

The total energy consumption according to the process was 4.49 Gcal / hr.

Example  3

In the above Example 1, 90% by weight of moisture and 99% by weight of formaldehyde were removed from the upper portion under the conditions of the following Table 1 at a temperature of 102 ° C and a pressure of 400 mmHg. (DMB solution) discharged to the lower portion of the line remover was transferred to a hydrogenation reactor and hydrogenated to produce Crude TMP. The resulting product was passed through a low boiling point eliminating column and a high boiling point eliminating column under the conditions shown in Table 1 below, Gt; TMP < / RTI > was obtained, respectively.

At this time, the obtained TMP had a 97.5% recovery of TMP against the added n-butyraldehyde and a purity of 99.99% or more.

The total energy consumption according to the process was 4.36 Gcal / hr.

Comparative Example  One

(B: F) molar ratio (B: F) of 1: 2 was used as n-butyraldehyde (B) and formaldehyde (F) And the aldol reaction was carried out in an aldol reactor at a temperature of 50 DEG C for 2 hours. The aldol reactor product was extracted with DMB under the conditions shown in Table 1 below, and then the crude TMP produced after the hydrogenation reaction was subjected to the purification of the organic solvent by removing the low-boiling impurities and high boiling point impurities under the conditions shown in Table 1 below, Gt; TMP < / RTI > and an organic solvent, respectively.

The obtained TMP had a 97.5% recovery of TMP against the charged n-butyraldehyde and a purity of 99.99% or more.

The total energy consumption according to the process was 4.71 Gcal / hr.

 [Test Example]

The characteristics of recovery, purity and water removal rate of TMP prepared in Examples 1 to 3 and Comparative Example 1 were measured by the following methods, and the results are shown in Table 2 below.

How to measure

* TMP recovery (%): ratio of final TMP product to TMP production by reaction

* TMP Purity (%): Ratio of pure TMP in final TMP product

* Water removal rate (% by weight): The ratio of the amount of water removed to the amount of water in the aldol reaction

Device Condition Example 1 Example 2 Example 3 Comparative Example 1 Flash
drum Theoretical singular 1st stage 1st stage 1st stage X Temperature (℃) 87 91 102 X Pressure (mmHg) 400 400 400 X Main material loss (Kg / hr) 1.8 3.4 10.1 X Water Removal Rate (%) 85 90 95 X Duty (Gcal / hr) 2.48 2.64 2.82 X Extractor Theoretical singular X X X 7th stage Solvent flow rate
(Kg / hr) X X X 3500 Pressure (mmHg) X X X 1500 Major substance loss
(Kg / hr) X X X 23 Water Removal Rate (%) X X X 47.1 Duty (Gcal / hr) X X X 0 Low boiling point
Removal tower Theoretical singular 10 steps 10 steps 10 steps 10 steps RR One One One 0.1 Top pressure
(mmHg) 50 50 50 190 Top temperature (℃) 107 113 121 112 Base temperature (℃) 226 226 226 253 Reb. Q 1.27 0.97 0.66 2.94 High point
Removal tower Theoretical singular 10 steps 10 steps 10 steps 10 steps RR 0.5 0.5 0.5 One Top pressure
(mmHg) 20 20 20 300 Top temperature (℃) 192 192 192 66 Base temperature (℃) 245 246 247 157 Reb. Q
(Gcal / hr) 0.88 0.88 0.88 1.09 Organic solvent
Tablet tower Theoretical singular X X X 10 steps RR X X X One Top pressure
(mmHg) X X X 300 Top temperature (℃) X X X 66 Base temperature (℃) X X X 157 Reb. Q (Gcal / hr) X X X 1.09

division Example 1 Example 2 Example 3 Comparative Example 1 TMP recovery (%) 97.5% 97.5% 97.5% 97.5% TMP Purity (%) 99.99% or more 99.99% or more 99.99% or more 99.99% or more Total energy usage
(Gcal / hr) 4.63 4.49 4.36 4.71

As shown in Table 1, Examples 1 to 3 of the present invention show that the total energy consumption is 4.36 Gcal / hr and 4.49 Gcal / hr at 4.71 Gcal / hr while maintaining the TMP recovery rate and purity as compared with Comparative Example 1 of the prior art. And 4.63 Gcal / hr, respectively, to 1.7%, 4.7% and 7.4%, respectively. In addition, since Comparative Example 1, which is a prior art, requires an extraction step using 2-ethylhexanol as an extraction agent and an organic solvent purification step to remove the organic solvent, it is necessary to perform an extraction step and an organic solvent purification step The process was simple and the energy consumption was greatly reduced, and the productivity was excellent.

Claims (15)

a) an aldol reactor in which n-butyraldehyde and formaldehyde are aldol-reacted in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylolbutane); b) a water and formaldehyde line remover which removes some or all of water and formaldehyde from the aldol reaction product comprising the DMB; c) a hydrogenation reactor for producing TMP (trimethylol propane) by hydrogenating the DMB from which the water and formaldehyde have been removed; And d) a purification apparatus for purifying the TMP.
The method according to claim 1,
Wherein the d) purification apparatus comprises: i) a low boiling point removal column for removing low boiling point impurities from the TMP; and ii) a high boiling point removal column for removing high boiling point impurities from the TMP.
The method according to claim 1,
Wherein the amine compound in the aldol reactor a) is trimethylamine, triethylamine or a mixture thereof.
The method according to claim 1,
Wherein the b) water and formaldehyde line eliminator are combined with a transfer pipe for transferring the removed aqueous formaldehyde solution to the aldol reactor.
The method according to claim 1,
Wherein the b) water and formaldehyde line eliminator is removed in an amount of 10 to 99% by weight in 100% by weight of water in the aldol reaction product containing DMB and 10 to 100% by weight in 100% by weight of formaldehyde Apparatus for the production of ol propane.
The method according to claim 1,
Wherein the b) water and formaldehyde line eliminator comprises a flash drum.
The method according to claim 1,
Wherein the apparatus for producing trimethylolpropane does not contain an organic solvent purification tower and an extractor.
1) Aldol reaction of n-butyraldehyde and formaldehyde in the presence of an amine compound as a catalyst to produce DMB (2,2-dimethylol butane);
2) removing some or all of water and formaldehyde from the aldol reaction product comprising the DMB of step 1);
3) hydrogenating TMB (trimethylol propane) by DMB in which water and formaldehyde are removed in step 2); And
4) distilling the product obtained in the step 3) to remove low boiling point impurities and high boiling point impurities and purifying the trimethylol propane.
9. The method of claim 8,
Wherein the amine compound in step 1) is trimethylamine, triethylamine or a mixture thereof.
9. The method of claim 8,
The water and the formaldehyde removed in the step 2) are transferred to the step 1) and reused.
9. The method of claim 8,
Wherein 10 to 99% by weight of 100% by weight of water in the aldol reaction product containing DMB is removed in step 2), and 10 to 100% by weight of 100% by weight of formaldehyde is removed. Gt;
9. The method of claim 8,
Wherein the aldol reaction product containing DMB in the step 2) is removed from a flash drum under a condition of a temperature of 85 to 105 ° C and a pressure of 350 to 450 mmHg to remove water and formaldehyde.
9. The method of claim 8,
Wherein the removal of the low boiling point impurities is carried out at a pressure of 35 to 65 mmHg through a low boiling point removal tower at a temperature of from 100 to 135 DEG C and a temperature of from 215 to 240 DEG C at step 4).
9. The method of claim 8,
Wherein the removal of the high boiling point impurities in the step 4) is carried out through a high boiling point removal tower at a pressure of 10 to 30 mmHg, a top temperature of 180 to 210 ° C and a bottom temperature of 230 to 260 ° C .
9. The method of claim 8,
Wherein the method for producing trimethylolpropane does not include extraction of an aldol reaction product containing DMB with an organic solvent and purification of an organic solvent.

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