KR100913885B1 - Purification method of crude naphthalene dicarboxylic acid using immobilized microorganism - Google Patents

Abstract

The present invention relates to a method for purifying crude naphthalene dicarboxylic acid, and more particularly, pellets a microorganism converting 2-formyl-6-naphthoic acid (FNA) to 2,6-naphthalene dicarboxylic acid (NDA). The present invention relates to a crude naphthalene dicarboxylic acid purification method using an immobilized microorganism, wherein the crude naphthalene dicarboxylic acid (cNDA) is purified and crystallized by immobilization on a ceramic type carrier. . According to the present invention, there is an advantage that can provide high yield and high purity of 2,6-naphthalene dicarboxylic acid (NDA) at an economical manufacturing cost.

Immobilized Microorganism, Crude Naphthalene dicarboxylic acid, 2-formyl-6-naphthoic acid, 2,6-naphthalene dicarboxylic acid (2,6-naphthalene dicarboxylic acid), crystallization

Description

Purification method of crude naphthalene dicarboxylic acid using immobilized microorganism

The present invention relates to a process for purifying crude naphthalene dicarboxylic acid (cNDA), more particularly, converting 2-formyl-6-naphthoic acid (FNA) to 2,6-naphthalene dicarboxylic acid (NDA). By immobilizing the microorganisms to pellet-type ceramics and purifying and crystallizing the crude naphthalene dicarboxylic acid (cNDA) using the microorganisms, 2,6-naphthalene dicarboxylic acid (NDA) can be used in an economical and efficient manufacturing process. The present invention relates to a method for purifying crude naphthalene polycarboxylic acid (cNDA) using an immobilized microorganism which can be mass produced.

Diesters of 2,6-naphthalene dicarboxylic acid and 2,6-naphthalene dicarboxylic acid are useful monomers for preparing various types of polymeric materials such as polyesters and polyamides. For example, poly (ethylene), which is a high performance polyester material, by condensation of a diester of 2,6-naphthalene dicarboxylic acid (hereinafter referred to as NDA) and 2,6-naphthalene dicarboxylic acid (hereinafter referred to as NDC) with ethylene glycol. 2,6-naphthalate) (hereinafter PEN) can be produced. Fibers and films made from PEN have higher strength and better thermal properties than poly (ethylene terephthalate) (hereinafter PET). This makes PEN suitable for making commercial items such as thin films that can be used to make magnetic recording tapes and electronic components. Films made of PEN are also useful for making food containers, especially food containers for high temperature fillings, due to their good resistance to gas diffusion, in particular carbon dioxide, oxygen and water vapor. It can also be used to make reinforcing fibers useful for making tire cords.

Currently, NDC is produced by oxidizing 2,6-dimethylnaphthalene (hereinafter, 2,6-DMN) to produce crude naphthalene dicarboxylic acid (hereinafter, cNDA) and then esterifying it. Currently, NDC is used as a main raw material when synthesizing PEN, but there are some problems compared to using 2,6-naphthalene dicarboxylic acid (hereinafter, NDA) as a raw material. First, water is produced during NDA condensation reaction, while methanol is a by-product in the case of NDC, and there is a risk of explosion. Second, NDA is esterified to obtain pure NDC during the NDC manufacturing process, and then NDC is produced through purification process. Therefore, one step process is needed compared to NDA, and thirdly, if you have an existing PET production facility, the use of NDC is not appropriate to use the existing facility. Despite the disadvantages of NDC, NDC is used instead of NDA in PEN production because it is still difficult to produce purified NDA having the purity required for polymerization.

In the oxidation of 2,6-DMN, cNDA containing various impurities such as 2-formyl-6-naphthoic acid (hereinafter referred to as FNA), 2-naphthoic acid (hereinafter referred to as NA) and trimellitic acid (hereinafter referred to as TMLA) Is generated. Among them, in particular, the presence of FNA causes the polymerization reaction to stop in the middle, which leads to a decrease in the degree of polymerization, thus adversely affecting the physical properties of the polymer or coloring of the polyester. Therefore, it is desirable to remove FNA, but it is not easy to remove it.

Therefore, in order to solve the above problems, there have been studies on methods for removing FNA present in cNDA and purifying NDA, including methods such as recrystallization, solvent treatment, melt crystal, high pressure crystal, supercritical extraction and CNDA is prepared by NDC using methanol, and then hydrated to produce NDA, or a chemical method of purifying NDA purified by a hydrogenation process, and the like, and specific examples thereof are as follows.

U.S. Pat. A method of producing naphthalene dicarboxylic acid is disclosed by removing until it is below ppm and then distilling the amine component by heating an aqueous solution containing the naphthalene dicarboxylic acid amine salt.

In addition, U.S. Patent No. 6,255,525 discloses a mixed solution of aromatic carboxylic acid and water containing impurities in a hydrogenated metal component in the presence of hydrogen gas at a temperature of 277-316 ° C, a pressure of 77-121 kg / cm2, and hydrogen gas. After contacting with a carbon catalyst free of hydrogenation metal component), the mixed solution is cooled to crystallize the aromatic carboxylic acid, and the crystallized aromatic carboxylic acid is recovered from the cooled mixed solution. Disclosed is a method for preparing an acid.

Next, in connection with the crystallization reaction of NDA, U.S. Patent No. 6,087,531 discloses a poly (alkylene naphthalene dicarboxylate) [poly (alkylene naphthalene dicerboxyla te)] at 125-400 ° C. , Hydride or alkali metal carbonate) and neutralized with acid at 170-240 ° C. to recover NDA crystals, or the polyester material was dissolved in NaOH and KOH solutions at 170-240 ° C. A method for recovering NDA crystals by neutralizing with acetic acid is disclosed.

Another US Pat. No. 6,426,431 discloses K ₂ -NDA aqueous solution treated with CO ₂ at 0-50 ° C. and 0-200 psi to form KH-NDA, wherein the ratio of KH-NDA to water is at least 1: 8. Suspended and then treated with CO ₂ again at 100 ° C. or higher (140-160 ° C.) and 100 psi or higher (175-250 psi) conditions to increase the purification yield of 2,6-NDA to about 45%. have.

However, in order to obtain high purity NDA crystals, the above-described methods require high temperature, high pressure conditions, long time treatment, and a large amount of expensive materials, and thus have a problem of low economical efficiency, and also have very low purification yield and purity. Agglomeration occurs between individual NDA crystals, making them difficult to apply in production.

The present invention is to solve the above-mentioned problems of the prior art, crude naphthalene dicarboxylic acid using immobilized microorganisms that can provide high-purity 2,6-naphthalene dicarboxylic acid (NDA) at an economical manufacturing cost ( cNDA) purification method.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention for achieving the above object is a crude naphthalene dicarboxylic acid to continuously purify and crystallize crude naphthalene dicarboxylic acid (cNDA) at room temperature and atmospheric pressure using a microorganism immobilized on a pellet-type ceramic carrier It relates to a method for purifying (cNDA).

According to the present invention, by purifying and crystallizing crude naphthalene dicarboxylic acid (cNDA) using microorganisms immobilized on a pellet-type ceramic carrier, the continuous purification process and the repeated use of microorganisms are possible, and thus the cost and equipment for culturing microorganisms Investment costs can be reduced. Therefore, the method of the present invention has the advantage of mass production of high purity 2,6-naphthalene dicarboxylic acid (NDA) at economical production cost and manufacturing process.

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

Purification method of crude naphthalene dicarboxylic acid (cNDA) using the immobilized microorganism according to the present invention, (a) primary washing step, (b) dissolution step, (c) reaction step, (d) crystallization step, (e) ) It consists of the second washing process and (f) drying process, described in detail step by step as follows.

(a) Step 1: Primary Washing Process

First, cNDA is washed with water at 150 to 300 ° C. to remove impurities such as 2-naphthoic acid (hereinafter referred to as NA), methylnaphthoic acid (hereinafter referred to as MNA), trimellitic acid (hereinafter referred to as TLMA) in advance.

Specifically, it is dispersed in hot water of 150 to 300 ℃, preferably 200 to 250 ℃ and stirred for 1 minute to 2 hours at a pressure of 1 to 28 kg / cm ² and then filtered to remove water The impurities are removed by repeating once, preferably twice.

In this case, when the temperature of the water exceeds 300 ℃, there may be a problem that the yield is greatly reduced due to the large amount of dissolved NDA, if less than 150 ℃ by-products such as NA, MNA, TLMA is not easily dissolved Can occur.

As such, when the cNDA is dispersed in hot water and washed several times under certain conditions, the other solubility can be removed by using the difference in solubility, and the FNA can also be removed to some extent so that subsequent purification and crystallization can be achieved. In this step, the amount of immobilized microorganisms and the amount of acid solution required for crystallization can be reduced.

In addition, in the production of cNDA, acetic acid and the like are used as a solvent, and the acid solution is contained in cNDA in a large amount. The acid solution is also removed through this washing process, thereby reducing the amount of alkali less than the next step of dissolving cNDA. Solution (eg KOH, NaOH, etc.) is consumed.

On the other hand, the amount of water is preferably used 5 to 20 times the weight of cNDA.

(b) second step: dissolution process

Before the washed cNDA is reacted with the immobilized microorganisms, a purified reaction solution is prepared by mixing with a buffer solution and then adding and dissolving an alkaline solution. That is, in this step, in order to react the cNDA with the immobilized microorganism, it is dissolved in a large amount using an alkaline solution in advance.

In this case, the buffer solution is not particularly limited, but water, sodium carbonate buffer solution (Na ₂ CO ₃ / NaHCO ₃ ), glycine buffer solution (Glycine / NaOH), potassium phosphate buffer solution (KH ₂ PO ₄ / KOH), Sodium phosphate buffer (Na ₂ HPO ₄ / NaH ₂ PO ₄ ), succinic acid buffer (Succinic acid / NaOH), sodium acetate buffer (Sodium acetate / Acetic acid), citric acid buffer (Citric acid / Sodium citrate), fatigue Sodium phosphate buffer (Na ₄ P ₂ O ₇ / HCl), boric acid buffer (Boric acid / NaOH), sodium borate buffer (Sodium borate / HCl) and the like can be used. Preferably, potassium phosphate buffer (KH ₂ PO ₄ -KOH) or boric acid buffer (Boric acid-NaOH) having a buffer range of pH 6.0 to 9.0 may be used. At this time, the concentration of the buffer solution is preferably used at a concentration of 0.01 to 100 mM.

The alkali solution is not necessarily limited, but NaOH or KOH is preferably used, and the amount of the alkali solution may be adjusted so that the pH ranges from 6 to 10.

In the present invention, since the acid solution contained in the cNDA is removed in advance through the washing process, the alkaline solution is consumed less, and the dissolution time of the cNDA is also shortened, which is more advantageous for the process operation.

Meanwhile, an organic solvent may be further added to the purification reaction solution of this step for the purpose of dissolving cNDA better. Examples thereof include dimethylsulfoxide (Dimethylsulfoxide, “DMSO”, and dimethylformamide (N, N). -Dimethylformamide, “DMF”, dimethylacetamide (N, N-Dimethylacetamide, “DNA”) and tetrahydrofuran (Tetrahydrofuran, “THF”), among others, and the use of dimethyl sulfoxide in terms of enzyme activity In this case, the concentration of the organic solvent is preferably 0.01 to 10%, but more preferably, it is preferably not added.When the amount of the organic solvent is added more than 10%, the cell membrane of the microorganism is dissolved to inhibit the reaction. Results.

(c) Step 3: Reaction Process

In this step, a Pseudomonas or Bacillus microorganism having the ability to convert FNA immobilized on a pellet-type ceramic carrier to NDA is reacted with the purified reaction solution obtained in step (b) to convert FNA in cNDA to NDA. To remove it.

As a means for purifying cNDA, immobilized microorganisms in which Pseudomonas or Bacillus microorganisms are immobilized on a ceramic carrier can be used for continuous processes and repeated use of microorganisms, and the size of the purification reactor can be designed small. Therefore, it is more economical in terms of manufacturing process and manufacturing cost than batch type process in which new microorganisms are introduced every time the reaction.

In addition, when the amount of microorganisms fixed to the carrier decreases due to death or cell detachment due to the continuous reaction, the amount of the microorganism can be easily increased and reused by putting the carrier into an immobilized culture medium and incubating it again. Therefore, in the case of using the immobilized microorganism, it is possible to obtain a saving effect in terms of incubation time as well as in the case of mass culture of the microorganism from the beginning in a fermenter.

The pellet-type ceramic carrier to be used as the carrier in the present invention may be used without any limitation as long as it is known in the art.

Pseudomonas or Bacillus microorganisms having the ability to convert FNA to NDA usable in the present invention is not particularly limited, but Bacillus F-1 (KCTC-10342BP), Bacillus F-3 (KCTC-10335BP) or Pseudomonas genus HN-72 (KCTC-10819BP) and the like is preferably used, the Bacillus genus F-1 and F-3 has been disclosed and published in the domestic application No. 2002-0087819, Pseudomonas genus HN-72 The strain has been published in Korean Patent Registration No. 10-0655030.

The Pseudomonas genus or Bacillus genus microorganisms can be immobilized by culturing through continuous culture in the airlift reactor shown in FIG. At this time, as the culture medium for immobilization may be used the same medium as the composition of Table 1, but is not necessarily limited thereto.

ingredient Furtherance glucose 0.5% Na ₂ HPO ₄ 0.6% KH ₂ PO ₄ 0.3% (NH ₄ ) ₂ SO ₄ 0.246% NaCl 0.05% MgSO ₄ 2 mM CaCl ₂ 1 mM Trace elements 0.01%

The reaction between the immobilized microorganism thus obtained and the purification reaction liquid obtained in step (b) is carried out using a fluidized bed reactor (FBR) shown in FIG. At this time, the reaction temperature is good to react at 25 to 50 ℃, preferably 35 to 40 ℃, especially when the reaction temperature is less than 25 ℃ or more than 50 ℃ significantly reduces the reactivity. In addition, the reaction time of the purified reaction solution in the reactor is 10 minutes to 1 hour, preferably 25 minutes to 45 minutes, more preferably 30 minutes to adjust the reaction to react in terms of removal and reactivity of the FNA good.

In particular, when the fluidized reactor used in the present invention (Fluidized Bed Reactor; FBR) is used there is an advantage that can not be blocked by the microorganisms appearing in the packed bed reactor (PBR) can be a stable long-term operation of the process.

(d) Step 4: Crystallization Process

In this step, an acidic solution is added to the reaction solution obtained in step (c) to adjust the pH to 1 to 4, and then reacted with stirring at a speed of 0 to 1000 rpm to crystallize the cNDA.

Specifically, in the crystallization reactor equipped with a stirrer, an appropriate amount of an acidic solution is added to the reaction solution obtained in step (c) in a manner of crystallizing cNDA in a state where FNA is removed and cNDA in an amorphous state present in the purification solution. After adjusting the pH to 1 to 4, and then continuously stirring at a rate of 0 to 1000rpm, preferably 0 to 400rpm to adjust to an appropriate temperature to maintain the reaction for a certain time, the crystallization is made at room temperature and atmospheric pressure conditions will be.

According to the crystallization process of the present invention, uniform cNDA crystals having a size of 100 μm or more can be obtained under normal temperature and normal pressure conditions, and thus are economical in terms of manufacturing cost and process, and there is no agglomeration phenomenon between the obtained cNDA individual crystals. This is high. In addition, since the amount of the alkaline solution used in step (b) is reduced, the amount of the acid solution used in the present step is also reduced, thereby reducing the manufacturing cost.

In this case, sulfuric acid, hydrochloric acid, glacial acetic acid, nitric acid, and the like may be used as the acid solution, and it is more preferable to use sulfuric acid or hydrochloric acid in terms of the size and yield of the cNDA crystal. That is, when sulfuric acid or hydrochloric acid is added, cNDA crystals having a uniform size of 100 µm or more can be obtained in high yield.

The reaction temperature for crystallization is suitable for carrying out the crystallization reaction is about 4 to 80 ℃, preferably 25 to 60 ℃, the reaction time is in the range of about 1 minute to 10 hours, preferably 2 minutes to 30 minutes Good in terms of continuous process. If the crystallization time is too short, the degree of crystallinity is low, aggregation may occur between individual crystals during the polymerization reaction, and excessively long crystallization time may cause unnecessary energy loss.

(e) Step 5: Secondary Cleaning Process

In this step, cNDA crystallized through step (d) is washed with water at 30 to 100 ° C. to remove salts contained therein.

In the present invention, since an alkaline solution such as KOH and an acidic solution such as sulfuric acid are used in the purification process and the crystallization process using the immobilized microorganism, salts such as K ₂ SO ₄ are generated after crystallization. Therefore, in order to remove it, a second washing process of cNDA crystallized with water at 30 to 100 ° C., preferably 40 to 80 ° C. is performed. At this time, when the temperature of the water exceeds 100 ℃ unnecessary energy loss occurs, if less than 30 ℃ may cause a problem that the salt is not removed at all.

Specifically, by dispersing the crystallized cNDA in water of 30 to 100 ℃ and stirred for 1 minute to 1 hour at atmospheric pressure and then filtered to remove the water several times it can be removed unnecessary salt, wherein The amount of water is preferably used 5 to 20 times the weight of NDA.

(f) Step 6: drying process

Through the secondary washing process, NDA crystals from which unnecessary salt compounds have been removed are dried at a constant temperature to obtain final pure NDA crystals. At this time, the drying treatment is preferably carried out at 30 to 200 ℃, the drying method can be used without limitation the conventional drying method known in the art to which the present invention belongs.

On the other hand, the immobilized microorganism used in the purification method of the crude naphthalene dicarboxylic acid ((cNDA)) of the present invention does not need to be removed separately, since the microorganism is immobilized on the carrier, and is removed in a very small amount, thereby affecting the subsequent process. Because it gives little.

Such pure NDA crystals obtained by the purification method of the present invention are obtained in high yield and high purity of 99.9% or more, and can be obtained in a crystalline or amorphous crystal state by adjusting treatment conditions depending on the use and case. In particular, in the case of the shape can have a lattice structure, but is not necessarily limited thereto.

In addition, since the NDA crystal produced in the present invention has an average particle diameter of 100 µm or more and has a uniform particle shape, the NDA crystal is very suitable for forming ethylene glycol and a low viscosity slurry during the PEN polymerization process. If the average particle diameter is small, the handling of the product is difficult, and the power to be consumed is high because the slurry formation ability is poor when the slurry is prepared by mixing with ethylene glycol in the PEN polymerization process. Preferably the NDA crystals of the present invention have an average particle diameter in the range of 100 to 180 μm.

3 shows an aspect of a purification apparatus system for carrying out a method for purifying crude naphthalene dicarboxylic acid (cNDA) using immobilized microorganisms according to the present invention. Based on the said FIG. 3, embodiment of the refinement | purification method of the crude naphthalene dicarboxylic acid (cNDA) using the immobilized microorganism by this invention is demonstrated in detail.

(1) After putting the cNDA slurry solution in the mixer (A) and heating it to 150-300 degreeC through the preheater (B), it puts into cNDA filtration and washing | cleaning apparatus (D), and pressure 1-28 kg / cm <^2> Stir for 1 minute to 2 hours.

(2) The slurry urea was filtered to obtain washed cNDA, and water was removed by a high pressure filtration liquid recovery device (E). If necessary, the water of 150-300 ° C. is supplied again from the solvent heating supply device (C), and the above (1) and (2) processes may be repeated one or two more times.

(3) Inject a certain amount of buffer solution into the dissolution tank (F), add cNDA obtained in the above (2), add an alkaline solution while stirring to dissolve the cNDA while adjusting the pH of the reaction solution, Again, a predetermined amount of water is added to prepare a purification reaction solution.

(4) While maintaining the purification reaction solution at a constant temperature, the reaction is passed through an immobilized microbial purification reactor (G) containing immobilized microbial cells. Through this process, FNA in cNDA can be converted to NDA in the immobilized microbial purification reactor (G) to remove FNA.

(5) Transfer the purified reaction solution to the crystallization reactor (H), and add an acidic solution to it and proceed with the crystallization while stirring.

(6) The slurry containing cNDA having completed crystallization is introduced into a filtration and washing apparatus (J). The filtration and washing apparatus (J) is provided with heating means for maintaining the temperature of the slurry solution at 30 ℃ to 100 ℃. In addition, the pressure is maintained at atmospheric pressure, it is equipped with a filter of 10 to 100㎛ for filtration.

(7) The filtration and washing device (J) is connected to the filtrate recovery device (K) to discharge the filtrate with the filtrate recovery device (K) and to filter the solid phase into the filter.

(8) Water preheated from 30 ° C. to 100 ° C. from the solvent heating supply device (I) was added to the filtration and washing device (J) again, washed, stirred for a predetermined time, and then the filtrate recovery device (K). Discharge the secondary filtrate. If necessary, the washing may be repeated one or two more times.

(9) The pure NDA remaining after washing forms a slurry by water pre-heated from the solvent heating supply device (I) at 30 ° C to 100 ° C, and is sent to the slurry recovery device (L) through the slurry discharge line.

(10) The pure NDA slurry sent to the slurry recovery device K removes the solvent from the powder separation device M, and is dried in the drying device N to recover the pure NDA.

It will be better understood by the following examples of the present invention, the following examples are intended to illustrate the present invention, and are not intended to limit the protection scope of the present invention as defined by the appended claims.

Example 1

Preparation of Immobilized Microorganisms

The culture medium having the composition shown in Table 1 was added to the airlift reactor as shown in FIG. 1, and air was fed at 0.5 to 2 v.v.m, and continuous culture of Pseudomonas HN-72 (KCTC-10819BP) was performed.

Pseudomonas genus HN-72 (KCTC-10819BP) was preincubated in LB liquid medium and then inoculated in an amount of 0.1 to 2% of the culture solution contained in the airlift reactor at 25 to 35 ° C (preferably 30 ° C) for 3 days The culture was in progress.

In order to determine the optimal dilution rate in the continuous culture, microorganisms were cultured and immobilized while changing from 0.1 to 2, and as shown in Table 2, the amount of cells to be immobilized was significantly increased until the dilution rate of 1.0. The rate of increase decreased significantly.

In addition, the immobilized cell mass was measured as follows, and the results are shown in Table 2 below. That is, Celite immobilized with Pseudomonas HN-72 was washed with distilled water to remove free cells, dried in an oven at 105 ° C. for 24 hours, and then the dry weight of cells + celite was adjusted. After removing the immobilized microorganisms by treatment with 6N HCl and 6N NaOH, washed three times with distilled water, dried again in an oven at 24O &lt; 0 &gt; C for 24 hours, and then measured the dry weight of celite. The immobilized cell mass was calculated based on the difference in dry weight.

Immobilized Cell Weight According to Dilution Rate Dilution rate (h ^-1 ) 0.1 0.5 1.0 1.5 2.0 Cell dry weight (mg.cells / g.celite) 40 95 170 178 182

Example 2

Immobilized Microorganisms cNDA Tablets

First step: first cleaning process

The cNDA slurry solution in the mixer (A) was heated to 220 ° C. or higher through the preheater (B), and then charged into a filtration and washing device (D), and stirred for 30 minutes at a pressure of 24.7 kg / cm ² and a temperature of 225 ° C. Next, the water was removed by filtration and the high-pressure filtrate recovery device (E). Then, 225 ° C. and 100 L of water were added from the solvent heating supply device (C) again, followed by stirring for 30 minutes under the same conditions, followed by filtration. It was.

 Second Step: Melting Process

Inject 50 L of 50 mM potassium phosphate buffer solution into the dissolution tank (F), add 1-10 kg of cNDA washed through the first step, and stir, add KOH so that the pH of the reaction solution is 8.0. After adjusting to dissolve the cNDA, water was added again to prepare 100 L of a purified reaction solution (cNDA concentration: 1 to 10%, FNA content in cNDA: 0.01 to 4%).

Step 3: Reaction Process

The microorganism obtained in Example 1 was immobilized in a fluidized bed reactor (FBR) as shown in Fig. 2 and the cNDA solution dissolved in the second step was injected and stirred to convert FNA in cNDA to NDA. Removed.

The temperature in the reactor was maintained at 40 ° C., and the stirring speed was 30 to 250 rpm.

Fourth Step: Crystallization Process

100 L of the cNDA purification solution obtained in the third step was transferred to a crystallization reactor (H) equipped with a stirring device, and the sulfuric acid solution was added thereto to adjust the pH to 2.0, and then the stirring speed was 50 rpm and the temperature was 40 The crystallization reaction proceeded for 20 minutes while maintaining at ℃.

After the crystallization was completed, the crystals were analyzed using a microscope and a particle size analyzer. As a result, the crystallization proceeded well, and it was confirmed that entanglement between the individual crystals did not occur. In addition, the average crystal size of the crystallized cNDA was analyzed to be about 130.2 ㎛.

Step 5: second wash process

The cNDA slurry solution crystallized in the fourth step was added to a filtration and washing apparatus (J), stirred at atmospheric pressure and temperature of 70 ° C. for 20 minutes, and then filtered to remove water with a filtrate recovery apparatus (K). Then, 70 ° C. and 100 L of water were added from the solvent heating supply device (I) again, followed by stirring for 20 minutes under the same conditions, followed by filtration, and the process of removing water with the filtrate recovery device (K) was repeated twice. . After adding 100L of water at 70 DEG C and 100L from the solvent heating supply device (I) again, the mixture was stirred for 20 minutes or more, and then evenly dispersed and transferred to the slurry recovery device (L), and then decanter (M). After the water was removed by using a drying apparatus (N) was dried at 120 ℃ to obtain a pure crystalline NDA.

For the first cNDA used in Example 2, cNDA obtained after the first step of the washing step, cNDA obtained after the purification reaction by the immobilized microorganisms in three steps, and cNDA obtained after the second washing and drying step of the fifth step After analyzing the components, the results are shown in Table 3 below.

First cNDA After the first wash After purification 2nd washing, after drying NA 0.0771% 0.0030% 0.0028% 0.0020% MNA 0.0463% 0.0025% 0.0027% 0.0024% FNA 0.0893% 0.0454% - - Etc 1.2840% 0.1270% 0.0774% 0.0797% NDA 98.5033% 99.8221% 99.9171% 99.9159%

When using the cNDA purification method of the present invention from the results of Table 3, it is possible to remove a considerable amount of other impurities such as NA, MNA after the first wash, in particular FNA after the purification reaction using the immobilized microorganism and the second wash, drying It can be seen that impurities in the cNDA including can be almost completely removed. In particular, it can be seen that the FNA is 100% converted to NDA to obtain high purity NDA crystals of 99.91% or more.

Example 3

Except for using the immobilized microorganism prepared by using Bacillus F-1 (KCTC-10342BP) instead of Pseudomonas HN-72 was carried out in the same manner as in Example 2 to obtain a pure crystalline NDA, Example After analyzing the components for cNDA in the same manner as 2, the results are shown in Table 4 below.

First cNDA After the first wash After purification 2nd washing, after drying NA 0.0771% 0.0030% 0.0031% 0.0022% MNA 0.0463% 0.0025% 0.0025% 0.0021% FNA 0.0893% 0.0454% - - Etc 1.2840% 0.1270% 0.1025% 0.1063% NDA 98.5033% 99.8221% 99.8919% 99.8894%

Example 4

Except for using the immobilized microorganism prepared using Bacillus F-3 (KCTC-10335BP) instead of Pseudomonas HN-72 was carried out in the same manner as in Example 2 to obtain a pure crystalline NDA, Example After analyzing the components for cNDA in the same manner as 2, the results are shown in Table 5 below.

First cNDA After the first wash After purification 2nd washing, after drying NA 0.0771% 0.0030% 0.0030% 0.0025% MNA 0.0463% 0.0025% 0.0026% 0.0025% FNA 0.0893% 0.0454% - - Etc 1.2840% 0.1270% 0.0997% 0.1006% NDA 98.5033% 99.8221% 99.8947% 99.8944%

Simple modifications or variations of the present invention can be readily used by those skilled in the art, and all such modifications or changes can be regarded as being included in the protection scope of the present invention.

1 is a schematic diagram of an airlift reactor used to immobilize microorganisms in a pellet-type ceramic carrier in the present invention,

FIG. 2 is a schematic diagram of a fluidized bed reactor (FBR) used to purify a crude naphthalene dicarboxylic acid (cNDA) solution dissolved in an alkaline solution using an immobilized microorganism in the present invention.

3 shows one aspect of a purification apparatus system for carrying out the process for purifying crude naphthalene dicarboxylic acid (cNDA) according to the present invention.

* Description of the symbols for the main parts of the drawings *

A: Mixer B: Preheater

C: Solvent heating supply device D: cNDA filtration and cleaning device

E: High pressure filtrate recovery device F: Dissolution tank

G: immobilized microorganism purification reactor H: crystallization reactor

I: Solvent Heater J: Filtration and Cleaning

K: Filtrate recovery device L: Slurry recovery device

M: Powder Separator N: Dryer

Claims (8)

Bacillus F-1 (KCTC-10342BP), Bacillus F-3 (KCTC-10335BP) or Pseudomonas converting 2-formyl-6-naphthoic acid (FNA) to 2,6-naphthalene dicarboxylic acid (NDA) Immobilized microorganisms comprising immobilizing the genus HN-72 (KCTC-10819BP) microorganisms on a pellet-type ceramic carrier to purify and crystallize crude Naphthalene dicarboxylic acid (cNDA) using the microorganisms. In the crude naphthalene dicarboxylic acid purification method used,  The purification method of the crude naphthalene dicarboxylic acid (cNDA), (a) a primary washing process in which crude naphthalene dicarboxylic acid (cNDA) is washed with water at 150 ° C to 300 ° C to remove impurities; (b) a dissolution step of preparing a purification reaction solution by mixing the washed crude naphthalene dicarboxylic acid (cNDA) with a buffer solution and then adding and dissolving an alkaline solution; (c) The microorganisms immobilized on the pellet-type ceramic carrier and the purified reaction solution in a fluidized reactor (Fluidized Bed Reactor; FBR) Reacting to remove 2-formyl-6-naphthoic acid (FNA) in the crude naphthalene dicarboxylic acid (cNDA);  (d) The acidic solution was added to the reaction solution obtained in step (c) to adjust the pH to 1 to 4, and the reaction was continued while stirring at a rate of more than 0 rpm and 1,000 rpm or less, and the crude naphthalene dicarboxylic acid ( crystallization process to crystallize cNDA); (e) a second washing step of washing the crystallized crude naphthalene dicarboxylic acid (cNDA) with water at 30 ° C. to 100 ° C. to remove salts contained therein; And (f) drying the washings obtained in step (e) to obtain 2,6-naphthalene dicarboxylic acid (NDA) in pure crystalline state; crude naphthalene dica using immobilized microorganisms, characterized in that the Purification Method of Leric Acid. delete According to claim 1, wherein the buffer of step (b), Select from the group consisting of sodium carbonate buffer, glycine buffer, potassium phosphate buffer, sodium phosphate buffer, succinic acid buffer, sodium acetate buffer, citric acid buffer, sodium pyrophosphate buffer, boric acid buffer and sodium borate buffer A method for purifying crude naphthalene dicarboxylic acid using an immobilized microorganism, characterized by using at least one kind thereof. The method of claim 3, wherein the concentration of the buffer solution is 0.01 mM to 100 mM. delete According to claim 1, wherein the reaction temperature of step (c) is 25 ℃ to 50 ℃, the reaction time is a purification method of crude naphthalene dicarboxylic acid using an immobilized microorganism, characterized in that 10 minutes to 1 hour. The method of claim 1, wherein the acid solution of step (d) is at least one selected from the group consisting of sulfuric acid, hydrochloric acid, glacial acetic acid and nitric acid. According to claim 1, wherein the reaction temperature of step (d) is 40 ℃ to 80 ℃, the reaction time is 1 minute to 10 hours, characterized in that the purification method of crude naphthalene dicarboxylic acid using an immobilized microorganism.

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