KR102419608B1 - Method for preparation of high concentration 3-hydroxypropionic acid aqueous solution - Google Patents

Abstract

The present invention is characterized in that by freeze-concentrating the 3-hydroxypropionic acid aqueous solution, there is no risk of physical properties change because high temperature is not applied, and a high-concentration 3-hydroxypropionic acid aqueous solution can be prepared in an environmentally friendly manner.

Description

Method for preparation of high concentration 3-hydroxypropionic acid aqueous solution

The present invention relates to a method for preparing a high-concentration 3-hydroxypropionic acid aqueous solution in an environmentally friendly manner without risk of physical property change by freeze-concentrating the 3-hydroxypropionic acid aqueous solution.

3-hydroxypropionic acid (3-HP) is a synthetic intermediate that can be used in various chemical processes. High value-added 1,3-propanediol, acrylic acid, methyl acrylate, acrylamide, ethyl 3-hydroxy It is an industrially important compound used as a raw material for the synthesis of various compounds such as propionic acid, malonic acid, propionlactone, and acronitrile.

3-HP can also be produced by a pure chemical process, but recently, it is produced by separation and purification from a low-concentration (<10wt%) 3-HP culture solution produced by a microorganism-based fermentation process. For such separation and purification, liquid-liquid extraction or reaction extraction techniques are generally used instead of the water evaporation method, which consumes a lot of energy.

The low-concentration 3-HP culture medium produced by the microorganism-based fermentation process can be generally prepared from the fermentation process of carbohydrates (eg, glucose) by anaerobic bacteria, generally at pH 5 to 7.5 conditions to increase productivity. Fermentation proceeds. At this time, a basic compound such as ammonia is added as a pH adjuster, and the organic acid thus generated is present in the form of ammonium organic acid. At this time, in order to convert the organic acid ammonium produced by the organic acid fermentation process to a pure organic acid, an additional treatment process is required.

However, since the product is a mixture containing various inorganic salts, organic carbon, organic acids and other by-products, selectively separating 3-HP therefrom to increase productivity while maintaining microbial activity is a difficult task. In addition, as a general separation process, there is a limit in terms of economic feasibility due to high energy consumption and expensive equipment. In particular, 3-HP is difficult to purify because polymerization proceeds during distillation.

Therefore, recovery of high-concentration 3-HP from low-concentration 3-HP aqueous solution prepared by microbial fermentation is a long-standing task in the field to which the present invention belongs, and an economical alternative process that can effectively separate and purify high-concentration organic acids from microbial fermentation broth continuously development is needed.

Accordingly, the present inventors have completed the present invention by confirming that it is possible to economically recover 3-HP at a high concentration from a low concentration 3-HP aqueous solution when freeze-concentration is used, as will be described later.

An object of the present invention is to provide a method for preparing a high-concentration 3-HP aqueous solution, which economically and environmentally friendlyly recovers a high-concentration 3-HP from a low-concentration 3-HP aqueous solution by using freeze-concentration.

In order to solve the above problems, the present invention provides a method for preparing a high concentration 3-hydroxypropionic acid aqueous solution, comprising the following steps:

Cooling an aqueous solution containing 3-hydroxypropionic acid (3-HP) to -50 °C to 0 °C, separating the solid phase and the liquid phase (step 1); and

removing the solid phase (step 2).

Hereinafter, the present invention will be described in detail for each step.

(Step 1)

Step 1 is a step of separating the 3-HP aqueous solution into a solid phase and a liquid phase using freeze-concentration.

Preferably, the aqueous solution containing 3-hydroxypropionic acid refers to a fermentation broth prepared by a microorganism-based fermentation process, and generally contains 10% by weight or less of 3-HP in the fermentation broth. do. In addition, the solvent of the aqueous solution generally refers to water, but is not necessarily limited thereto, and includes all solvents used in a microorganism-based fermentation process.

The fermentation broth can be prepared by culturing microorganisms having the ability to produce 3-HP using glycerol as a carbon source. The microorganism may include, but is not limited to, the E. coli W3110 strain in which the GDH and ALDH enzymes are improved, and includes all of the E. coli strains.

In addition, prior to performing step 1, purification such as filtration may be performed to remove impurities present in the aqueous solution containing 3-hydroxypropionic acid.

In order to separate the aqueous solution containing 3-hydroxypropionic acid into a solid phase and a liquid phase in step 1, the aqueous solution containing 3-hydroxypropionic acid is cooled to -50°C to 0°C. When the cooling temperature is more than 0 ° C., a solid phase is not generated, and when the cooling temperature is less than -50 ° C., all of the aqueous solution containing 3-hydroxypropionic acid becomes a solid phase, so there is a problem that the liquid phase and the solid phase cannot be separated.

The cooling temperature is not particularly limited as long as it is a temperature at which a part of the aqueous solution changes to a solid phase, preferably -25°C to 0°C, and more preferably -15°C to -5°C.

As the aqueous solution containing 3-hydroxypropionic acid is cooled as described above, the solvent is partially changed to a solid phase, and 3-HP is not present or is present in a trace amount in the solid phase. The higher the concentration of 3-HP, the lower the freezing point, so the separation of the solid phase and the liquid phase becomes easy.

(Step 2)

Step 2 is a step of removing the solid phase from the solid phase and the liquid phase separated in step 1.

As described above, 3-HP does not exist or exists in a trace amount in the solid phase, and as a result, 3-HP is concentrated in the liquid phase by removing the solid phase.

The removal of the solid phase may be performed by removing the solid phase at a time after the solid phase and the liquid phase are separated, or by continuously removing the solid phase when the solid phase is generated in step 1. In addition, as a method of removing the solid phase, it may be removed through a method such as filtration.

On the other hand, a trace amount of 3-HP may be present in the separated solid phase, and thus 3-HP may be recovered through additional freeze-concentration.

That is, after melting the solid phase removed in step 2, the processes of steps 1 and 2 may be repeated. Specifically, after melting the solid phase removed in step 2, cooling to -50 ° C. to 0 ° C. separating the solid phase and the liquid phase, and removing the solid phase, the liquid phase is mixed with the liquid phase of step 2 Additional steps may be included. The cooling, separation and removal conditions applied in the above steps may be applied to the conditions applied in steps 1 and 2 above.

At this time, the melting is not particularly limited as long as the temperature at which the solid phase changes to the liquid phase is not particularly limited, but it is preferable to melt at 10 to 30° C. so that it does not exist as a dimer through 3-HP reaction.

According to the manufacturing method according to the present invention described above, the concentration (unit: g/L) of 3-hydroxypropionic acid in the aqueous solution containing 3-hydroxypropionic acid used in step 1 can be increased by 2 to 10 times. There is this.

In addition, 3-hydroxypropionic acid may be changed to a dimer by reacting with each other at a high temperature. Since the manufacturing method according to the present invention described above does not include a high temperature treatment, this change can be suppressed.

Furthermore, the manufacturing method according to the present invention described above does not require a special device other than a device for cooling, so expensive equipment is not required, and it has the advantage of being environmentally friendly.

As described above, the present invention is characterized in that, by freeze-concentrating the 3-hydroxypropionic acid aqueous solution, there is no risk of physical properties change because high temperature is not applied, and a high-concentration 3-hydroxypropionic acid aqueous solution can be prepared in an environmentally friendly manner.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for easier understanding of the present invention, and thus the content of the present invention is not limited thereto.

Example One

In a 500 ml glass jacket reactor connected to a circulator, an aqueous 3-HP solution (250 ml) containing 29 g/L of 3-HP (3-hydroxypropionic acid) was added. After stirring the 3-HP aqueous solution for 5 minutes, the temperature was lowered to -10°C by cooling at a cooling rate of about 1°C/min until it became a slurry in which solid and liquid were mixed. Then, after collecting the solid phase holding the liquid phase, it was separated into a liquid phase (82.9 mL) and a solid phase (167.1 mL; about 172.7 g) using filter paper and a vacuum pump.

As a result of measuring the concentration of 3-HP for the double solid phase, it was confirmed that 3-HP was concentrated in the liquid phase as 9.85 ± 0.04 g/L of 3-HP was present. In addition, as a result of measuring the concentration of 3-HP in the liquid phase, 67.56 g/L of 3-HP was present, and as a result of analyzing the components of the liquid phase, no dimer was detected.

Example 2

In a 500 ml glass jacket reactor connected to a circulator, an aqueous 3-HP solution (250 ml) containing 29 g/L of 3-HP was added. After stirring the 3-HP aqueous solution for 5 minutes, the temperature was lowered to -10°C by cooling at a cooling rate of about 1°C/min until it became a slurry in which solid and liquid were mixed. Then, after collecting the solid phase holding the liquid phase, it was separated into a liquid phase (first liquid phase) and a solid phase using filter paper and a vacuum pump.

After washing the separated solid phase with distilled water, the same process was performed to separate a liquid phase and a solid phase once more, and separated into a liquid phase (second liquid phase) and a solid phase (167 mL; about 172.5 g). As a result of measuring the concentration of 3-HP for the double solid phase, it was confirmed that 3-HP was concentrated in the liquid phase because 3-HP of 0.74 ± 0.04 g/L was present.

After mixing the obtained two liquid phases (the first liquid phase and the second liquid phase) to obtain a liquid phase of about 97.6 mL, the concentration of 3-HP was measured. As a result, 72.97 g/L of 3-HP was present. , As a result of analyzing the components of the liquid phase, no dimer was detected.

comparative example

A 3-HP aqueous solution (300 ml) containing 29 g/L of 3-HP was put into a 500 ml glass jacket reactor connected to a circulator. After stirring the 3-HP aqueous solution for 5 minutes, the temperature was raised to 40°C. Then, it was operated for 1.5 hours while maintaining 30 mbar using a vacuum pump. Then, as a result of analyzing the components of the aqueous solution in the reactor, it was confirmed that about 31 wt% of 3-HP was present as a dimer.

As described above, in the case of Examples 1 and 2 according to the present invention, the solid phase and the liquid phase can be separated by freeze-concentration, and a trace amount of 3-HP is present in the solid phase, and as a result, it can be confirmed that 3-HP is concentrated in the liquid phase. there was. In addition, since the process does not apply a high temperature condition, it can be confirmed that a component such as a dimer is not detected as in the comparative example to which a high temperature is applied.

Claims (8)

Cooling an aqueous solution containing 3-hydroxypropionic acid to -50 °C to 0 °C, separating the solid phase and the liquid phase (step 1); and
Including the step of removing the solid phase (step 2)
In the method for producing a high-concentration aqueous 3-hydroxypropionic acid solution,
The concentration of 3-hydroxypropionic acid in the high-concentration aqueous solution of 3-hydroxypropionic acid (g/L) is the concentration of 3-hydroxypropionic acid in the aqueous solution containing 3-hydroxypropionic acid used in step 1 (g/L) ) 2 to 10 times higher than
A method for preparing a high-concentration aqueous 3-hydroxypropionic acid solution.
According to claim 1,
The cooling temperature of step 1 is -25 ℃ to 0 ℃,
manufacturing method.
According to claim 1,
The cooling temperature of step 1 is -15 ℃ to -5 ℃,
manufacturing method.
According to claim 1,
Step 2 is removing the solid phase by filtration,
manufacturing method.
According to claim 1,
After melting the solid phase removed in step 2, cooling to -50°C to 0°C to separate the solid phase and liquid phase (step 3), and
Removing the solid phase of step 3, and further comprising the step of mixing the liquid phase of step 3 with the liquid phase of step 2 (step 4),
manufacturing method.
6. The method of claim 5,
The melting of step 3 is carried out at 10 to 30 ℃,
manufacturing method.
delete According to claim 1,
The aqueous solution containing 3-hydroxypropionic acid is a fermentation broth prepared by a microorganism-based fermentation process,
manufacturing method.