KR20220141406A - Butyric acid adsorbent using zeolite and butyric acid adsorption separation method using the same - Google Patents

Abstract

The present invention relates to a butyric acid adsorbent using zeolite and a butyric acid adsorption separation method using the same, and more particularly, to a butyric acid adsorbent containing zeolite, which can selectively separate butyric acid among organic acids produced during carbon source fermentation, and has excellent adsorption performance for butyric acid regardless of the concentration of butyric acid, and to a butyric acid adsorption separation method using the same.

Description

Butyric acid adsorbent using zeolite and butyric acid adsorption separation method using same

The present invention relates to a butyric acid adsorbent using zeolite and a butyric acid adsorption separation method using the same, and more particularly, it is possible to selectively separate butyric acid from organic acids produced during carbon source fermentation, and to It relates to a butyric acid adsorbent containing zeolite having excellent adsorption performance, and a butyric acid adsorption separation method using the same.

As a next-generation biofuel, butanol is attracting attention. Butanol is evaluated as a biofuel to replace ethanol because it has a higher energy density than ethanol, which reduces fuel efficiency loss, has low water solubility and corrosiveness, and has an excellent greenhouse gas reduction effect.

Butyric acid (butanoic acid) is recognized for its value as a precursor of such butanol, and is used in various industries such as pharmaceutical industry, chemical industry, beverage, food or cosmetics.

As a method for producing butyric acid, chemical synthesis, extraction from butter, fermentation, and the like are known. In particular, a large amount of organic acids are produced as by-products during fermentation of carbon sources using microorganisms, and butyric acid accounts for the largest portion among organic acids. Therefore, the process of selectively separating and recovering butyric acid from among organic acids for industrial use of butyric acid is very important.

As a conventional method for separating and recovering butyric acid, there are various methods such as distillation, electrodialysis, liquid-liquid extraction, pervaporation, and adsorption separation. However, the distillation method has disadvantages in that the required space is large, high cost and high energy are required, and the electrodialysis method has a disadvantage in that the purity of the recovered material is low. The liquid-liquid extraction method has a problem in that the process is complicated because the extract is recovered using back extraction or distillation after the separation process. There is a problem that the performance is degraded.

Accordingly, in the present invention, in addition to the conventional butyric acid separation methods, a technology for a butyric acid separation method with a simpler process, shorter time required, economical, and excellent selectivity and recovery rate has been developed.

Republic of Korea Patent Publication No. 10-2004-0091215

The present invention is to solve the above problems, and the present invention is to selectively separate butyric acid from organic acids produced during carbon source fermentation by using a zeolite whose properties such as pore size are adjusted to match the physical properties of butyric acid. It is intended to provide an adsorbent for butyric acid. In addition, the present invention aims to provide a simpler and more economical butyric acid adsorption separation method by exhibiting excellent adsorption performance for butyric acid regardless of the concentration of butyric acid.

These and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object is to be achieved by a zeolite adsorbent, characterized in that it is composed of an aluminosilicate zeolite skeleton having a plurality of micropores and has selectivity for butyric acid from a mixed component comprising water and at least one organic acid component. can

The size of the micropores may be 3.5 to 15 Å. The zeolite may have a Si/Al ratio of 2.5 to 50.0. The zeolite may be any one selected from LTA type, MFI type, FAU type and CHA type. The organic acid may be butyric acid, acetic acid, propionic acid, or a combination thereof.

The above object is to prepare an adsorbent by calcining an aluminosilicate zeolite, a step of first stirring an acid aqueous solution containing one or more organic acid components, a second stirring after mixing the acid aqueous solution and the adsorbent step to do and

After the secondary stirring, centrifugation may be performed to separate butyric acid and an adsorbent from the aqueous acid solution, which may be achieved by a butyric acid adsorption separation method.

The calcination, heat treatment of the zeolite at a temperature increase rate of 0.5 to 1.5 ° C./min, heating the zeolite from 24 to 26 ° C. to a temperature range of 530 to 560 ° C. For 7 to 9 hours after the temperature increase, the 530 to 560 It may include the step of maintaining a temperature range of °C. The calcination is to form a porous structure having a plurality of micropores in the zeolite, and the size of the micropores may be 3.5 to 15 Å.

The zeolite may have a Si/Al ratio of 2.5 to 50.0. The primary stirring may be performed at 24 to 26° C., at a speed of 450 to 550 rpm, for 1.5 to 2.5 hours. The adsorbent may be mixed in an amount of 0.010 to 0.050 parts by weight based on 1 part by weight of the aqueous acid solution.

The secondary stirring may be performed at 20 to 40 °C, at a speed of 750 to 850 rpm, for 23 to 25 hours. The centrifugation may be performed at a speed of 12,500 to 14,500 rpm for 10 to 20 minutes. The organic acid may be butyric acid, acetic acid, propionic acid, or a combination thereof. The zeolite may be any one selected from LTA type, MFI type, FAU type and CHA type.

According to the present invention, it is possible to provide a butyric acid adsorbent capable of selectively separating butyric acid from among organic acids generated during fermentation of a carbon source.

In addition, according to the present invention, it is possible to provide a simpler and more economical butyric acid adsorption separation method by exhibiting excellent adsorption performance for butyric acid regardless of the concentration of butyric acid.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a flowchart sequentially showing a butyric acid adsorption separation method according to an embodiment of the present invention.
2 is a graph showing the results of the experimental example of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those of ordinary skill in the art that these examples are only presented as examples to explain the present invention in more detail, and that the scope of the present invention is not limited by these examples. .

Further, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and in case of conflict, this specification, including definitions description will take precedence.

In order to clearly explain the invention proposed in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification. And, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, the "unit" described in the specification means one unit or block that performs a specific function.

In each step, the identification code (first, second, etc.) is used for convenience of description, and the identification code does not describe the order of each step, and each step does not clearly describe a specific order in context. It may be performed differently from the order specified above. That is, each step may be performed in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings. However, it may not be limited to these embodiments and examples and drawings of the present application.

The zeolite adsorbent of the present invention is composed of an aluminosilicate zeolite skeleton having a plurality of micropores, and has selectivity to butyric acid from a mixed component comprising moisture and at least one organic acid component. do it with The zeolite may be used as a structured or powder zeolite, or may be used as a membranous zeolite formed by bonding to a porous support such as alumina. For example, the zeolite may be of a structured type.

The adsorbent may be a zeolite having a micropore size of 3.5 to 15 Å, specifically, 3.8 to 7.4 Å. For example, the zeolite may be an LTA type, an MFI type such as Silicalite-1 or ZSM5, a FAU type, or a CHA type such as SAPO-34. The zeolite may have a Si/Al ratio of 2.5 to 50, more specifically, a Si/Al ratio of 1 to 5.

As an example, the adsorbent may be an LTA type zeolite. The size of the micropores of the zeolite may be 3.81 to 5.5 Å, specifically, 4.0 Å, and the zeolite may have a Si/Al ratio of 2.5 to 3.5, specifically, 3.06. As the adsorbent, if the zeolite has a micropore size and a Si/Al ratio within the above-mentioned range, even if butyric acid is contained in a high concentration in the mixed component, selectivity and adsorption efficiency for butyric acid can be significantly improved.

When the size of the micropores of the zeolite and the ratio of Si/Al are out of the above range, when the butyric acid is lower or higher than a specific concentration, the selectivity and adsorption efficiency for butyric acid may be lowered, and in particular, butyric acid is a mixed component If it is contained in a high concentration in the , the selectivity and adsorption efficiency for butyric acid may be significantly lowered.

The mixed component is not particularly limited as long as it is a mixed component containing butyric acid. The mixed component may include, for example, an organic acid and water generated as a by-product when a carbon source is fermented from a microorganism. The fermentation may be, for example, acetone-butanol-ethanol fermentation (ABE fermentation), which is a process for producing acetone, 　butanol and ethanol from carbohydrates.

As the microorganism, any strain capable of producing an organic acid including butyric acid through a fermentation process , specifically, acid fermentation can be used. For example, the microorganism is an anaerobic bacterium, Clostridium tyrobutylicum, Clostridium butylicum, Clostridium acetobutyricum (Clostridium acetobutyricum) or Clostridium baserlinky (Clastridium beijerinckii), but is not limited thereto.

Specifically, the carbon source is a carbohydrate, for example, a substrate capable of saccharification such as corn starch containing sugar, sugar, cellulose, plant raw materials such as sugar cane juice, seaweed, organic waste, etc. (e.g., glucose, glycerol), but is not limited thereto. Specifically, the carbon source may be a food waste resource, that is, a food-derived carbon source generated in the process of production, distribution, processing, and cooking of food or remaining from agricultural/water/livestock products.

In other words, the present invention is a carbon source, for example, by selectively separating butyric acid, which occupies the largest portion of organic acids generated from food waste resources, for example, using as a precursor of butanol, a biofuel, a more environmentally friendly and economical replacement. It can contribute to resource production.

The organic acid may be an organic acid (volatile organic acid) generated during the fermentation, but is not limited thereto. For example, the organic acid is, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid (Isovaleric acid) or a combination thereof. For example, the organic acid may be acetic acid, propionic acid, butyric acid, or a combination thereof.

1 is a flowchart sequentially illustrating a butyric acid adsorption separation method according to an embodiment of the present invention.

Referring to FIG. 1 , the butyric acid adsorption separation method includes the steps of preparing an adsorbent by calcining an aluminosilicate zeolite; First stirring an aqueous acid solution containing an organic acid component; Secondary stirring after mixing the acid aqueous solution and the adsorbent; and separating the butyric acid and the adsorbent from the aqueous acid solution by centrifugation after the secondary stirring. The butyric acid adsorption separation method according to the present invention enables the butyric acid to be adsorbed and separated with high efficiency even in a simpler and more economical process compared to the prior art.

Hereinafter, the butyric acid adsorption separation method is the same as the description of the above-described adsorbent, except for the details described later.

The calcination may be a process of heat-treating the zeolite to form a porous structure in the zeolite and further strengthen the skeletal structure of the zeolite. Specifically, in the calcination, the zeolite is heat-treated at a temperature increase rate of 0.5 to 1.5 ℃ / min, specifically 1 ℃ / min, 24 to 26 ℃, specifically, 530 to 560 ℃ at 25 ℃, specifically, It can be heated to a temperature range of 550 °C. Thereafter, the temperature range of 530 to 560°C, specifically, 550°C, may be maintained for 7 to 9 hours, specifically, for 8 hours.

The conditions of the above-described calcination allow the zeolite to form a porous structure having high selectivity for butyric acid. In other words, the conditions of the above-described calcination may be such that the size of the micropores in the porous structure of the zeolite is in the range of 3.5 to 15 Å.

The zeolite may be LTA type, MFI type such as Silicalite-1, ZSM5, FAU type, or CHA type such as SAPO-34. The zeolite may have a Si/Al ratio of 2.5 to 50, more specifically, a Si/Al ratio of 1 to 5.

For example, the adsorbent may be an LTA type zeolite. The size of the micropores of the zeolite may be 3.81 to 5.5 Å, specifically, 4.0 Å, and the zeolite may have a Si/Al ratio of 2.5 to 3.5, specifically, 3.06. As the adsorbent, if the zeolite has a micropore size and a Si/Al ratio within the above-mentioned range, even if butyric acid is contained in a high concentration in the mixed component, selectivity and adsorption efficiency for butyric acid can be significantly improved.

If the size of the micropores of the zeolite and the ratio of Si/Al are out of the above range, when the butyric acid is lower or higher than a specific concentration, the selectivity and adsorption efficiency for butyric acid may be reduced, and in particular, butyric acid is a mixed component If it is contained in a high concentration in the , the selectivity and adsorption efficiency for butyric acid may be significantly lowered.

The acid aqueous solution may be mixed with distilled water, for example, secondary distilled water in an amount of 50 to 500 times by weight based on 1 weight of the organic acid. The organic acid may be at least one organic acid including butyric acid. For example, the organic acid may be acetic acid, propionic acid, butyric acid, or a combination thereof, but is not limited thereto. The concentration of the aqueous acid solution may be, for example, 0.1 to 15 g/L, specifically, 1 to 14 g/L, and more specifically, 2 to 12 g/L.

The aqueous acid solution may be subjected to primary stirring. The first stirring may be performed at 24 to 26°C, specifically, at 25°C, at a rate of 450 to 550 rpm, specifically, 500 rpm, for 1.5 to 2.5 hours, specifically, for 2 hours.

In order to compare the concentration of butyric acid in the acid aqueous solution and the butyric acid concentration after the adsorption separation to be performed later, as an example, 5 to 10 parts by weight of an organic solvent, for example, ethanol, is mixed with 1 part by weight of the acid aqueous solution by gas chromatography (gas chromatography, Shimadzu, GC-2030) may be performed.

The secondary stirring may be a process in which the adsorbent adsorbs butyric acid in the acid aqueous solution while the adsorbent and the acid aqueous solution are mixed in an embodiment of the present invention. The adsorbent may be mixed in an amount of 0.010 to 0.050 parts by weight, specifically, 0.020 to 0.030 parts by weight, more specifically, 0.022 to 0.027 parts by weight, for example, 0.025 parts by weight based on 1 part by weight of the acid aqueous solution. If the content of the adsorbent is out of the above range, the yield of the adsorbent may be lowered.

Specifically, the secondary stirring may be performed for 23 to 25 hours, specifically, for 24 hours at a speed of 750 to 850 rpm, specifically, 800 rpm, at 20 to 40° C., specifically, 30° C. . By the secondary stirring under the above conditions, the adsorbent can selectively adsorb and separate butyric acid from one or more organic acids including butyric acid in a simpler and more economical process.

The centrifugation may be a process of separating butyric acid, which is an adsorbent material adsorbed to the adsorbent. Specifically, the centrifugation may be performed at a speed of 12,500 to 14,500 rpm, specifically, 13,500 rpm, for 10 to 20 minutes, specifically, 15 minutes. When the centrifugation is performed under the conditions in the above-mentioned range, the yield of butyric acid, which is the finally obtained adsorbent material, can be further increased.

After the centrifugation, in order to measure the concentration after adsorption of the adsorbent material, that is, butyric acid, as an example, 5 to 10 times the total weight of the acid aqueous solution separated from the adsorbent material is mixed with an organic solvent, for example, ethanol Thus, gas chromatography (Shimadzu, GC-2030) can be performed.

By substituting the concentrations before and after the adsorption separation of butyric acid into Equation 1 below, the amount (g) of the adsorbed material adsorbed per unit mass (g) of the adsorbent can be calculated.

q : amount of adsorbate adsorbed per unit mass (g) of adsorbent (g)

m: mass of adsorbent (g)

C _i : Concentration of butyric acid aqueous solution before adsorption separation experiment (g/L)

C _f : Concentration of butyric acid aqueous solution (g/L) after adsorption separation experiment

V : Volume of butyric acid aqueous solution used in adsorption separation experiment (L)

The adsorbed-separated butyric acid, for example, may be converted into butanol and the like to be used as a biofuel. The conversion to butanol may follow known techniques. As an example, a chemical conversion method including a process of producing butyl butyrate from butyric acid through an esterification reaction and hydrogenating all or part of butyl butyrate to obtain butanol may be followed. Accordingly, butylbutyrate can be utilized as a next-generation biofuel for high-quality gasoline together with butanol.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through specific examples and comparative examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Experimental example]

Each adsorbent of Example 1-5 [LTA (pore size: 4.0 Å), Silicalite-1 (5.6 Å), ZSM-5 (5.6 Å), FAU (7.4 Å), SAPO-34 (3.8 Å)] was calcined. and prepared. The calcination was carried out by heat treatment from 25 °C to 550 °C at a temperature increase rate of 1 °C/1 min, and then maintaining the temperature at 550 °C for 8 hours. Then, the content and concentration of n-butyric acid were varied and each mixed with 40 ml of secondary distilled water, and then stirred at 25 ° C. at 500 RPM for 2 hours or more to prepare an aqueous solution of n-butyric acid. Then, 0.3 ml of an aqueous acid solution and 2 ml of ethanol were mixed, and the concentration before the adsorption separation experiment was measured using gas chromatography (Shimadzu, GC-2030).

1 ml of each n-butyric acid aqueous solution and 0.025 g of each adsorbent were mixed and stirred at 30° C. at 800 RPM while maintaining the speed for 24 hours. After 24 hours, the centrifuge was operated at 13,500 rpm for 15 minutes to separate the adsorbent and the aqueous acid solution. After mixing 0.3 ml of the separated aqueous acid solution and 2 ml of ethanol, the concentration after adsorption separation was measured using gas chromatography (Shimadzu, GC-2030).

The concentration (Ci) before the adsorption separation experiment and the concentration after the adsorption separation experiment (Cf) were substituted into Equation 1 below to calculate the amount of adsorbed material (g) per unit mass (g) of the adsorbent. For accurate analysis, the experiment was performed twice, and the average value is shown in Table 1 and FIG. 2 below.

[Equation 1]

2 is a graph showing the results of the experimental example of the present invention.

Referring to Table 1 and FIG. 2 together, it was confirmed that the zeolite of Examples exhibited adsorption performance for butyric acid. Among them, it was confirmed that, when the LTA type adsorbent of Example 1 was used, even when the butyric acid concentration was increased, the adsorption separation performance was consistently excellent.

In this specification, only a few examples among the various embodiments performed by the present inventors will be described, but the technical spirit of the present invention is not limited or limited thereto, and it is of course that it may be modified and variously implemented by those skilled in the art.

Claims (15)

It consists of an aluminosilicate zeolite skeleton having a plurality of micropores,
A zeolite adsorbent, characterized in that it has selectivity for butyric acid from a mixed component comprising water and at least one organic acid component. According to claim 1,
The size of the micropores is characterized in that 3.5 to 15Å, zeolite adsorbent. According to claim 1,
The zeolite, Si / Al ratio of 2.5 to 50.0, characterized in that the zeolite adsorbent. According to claim 1,
The zeolite is, characterized in that any one selected from LTA type, MFI type, FAU type and CHA type, zeolite adsorbent. According to claim 1,
The organic acid is butyric acid, acetic acid, propionic acid or a combination thereof, characterized in that, zeolite adsorbent. preparing an adsorbent by calcining the aluminosilicate zeolite;
First stirring an aqueous acid solution containing at least one organic acid component;
Secondary stirring after mixing the acid aqueous solution and the adsorbent; And
Separating butyric acid and adsorbent from the acid aqueous solution by centrifugation after the secondary stirring; including, butyric acid adsorption separation method. 7. The method of claim 6,
The calcination is
Heating the zeolite at a temperature increase rate of 0.5 to 1.5 °C/min, and heating the zeolite from 24 to 26 °C to a temperature range of 530 to 560 °C; and
After the temperature rise, for 7 to 9 hours, maintaining the temperature range of 530 to 560 ℃; characterized in that it comprises a, butyric acid adsorption separation method. 8. The method of claim 7,
The calcination is to form a porous structure having a plurality of micropores in the zeolite,
The size of the micropores, characterized in that 3.5 to 15Å, butyric acid adsorption separation method. 7. The method of claim 6,
The zeolite is, butyric acid adsorption separation method, characterized in that the ratio of Si / Al is 2.5 to 50.0. 7. The method of claim 6,
The primary stirring is at 24 to 26 ℃, at a speed of 450 to 550 rpm, will be carried out for 1.5 to 2.5 hours, butyric acid adsorption separation method. 7. The method of claim 6,
The adsorbent is to be mixed in 0.010 to 0.050 parts by weight based on 1 part by weight of the acid aqueous solution, butyric acid adsorption separation method. 7. The method of claim 6,
The secondary stirring, at 20 to 40 ℃, at a speed of 750 to 850 rpm, characterized in that carried out for 23 to 25 hours, butyric acid adsorption separation method. 7. The method of claim 6,
The centrifugation is, at a speed of 12,500 to 14,500 rpm, butyric acid adsorption separation method, characterized in that it is performed for 10 to 20 minutes. 7. The method of claim 6,
The organic acid is butyric acid, acetic acid, propionic acid, or a combination thereof, characterized in that the, butyric acid adsorption separation method. 7. The method of claim 6,
The zeolite is, characterized in that any one selected from LTA type, MFI type, FAU type and CHA type, butyric acid adsorption separation method.

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