Membrane separation method for separating carbonate-containing diaminoalkane solution

Abstract

The present invention provides a method for removing carbon dioxide from a carbonate-containing solution of a diaminoalkane, the method comprising the step of passing the carbonate-containing solution of the diaminoalkane through a membrane module; and a method for preparing a diaminoalkane comprising the same.

Description

Technical Field

[0001] The present disclosure relates to a method for removing carbon dioxide from a carbonate-containing diaminoalkane solution, the method including the step of passing the carbonate-containing diaminoalkane solution through a membrane module; and a method for preparing a diaminoalkane including the same. Background Art

[0002] Among diaminoalkane compounds having amino groups at both ends of a saturated hydrocarbon skeleton, 1,5-diaminopentane (which is a compound called cadaverine) is a diamine compound having an unpleasant odor that is initially produced during the decomposition of animal tissues. However, it is a product of the decarboxylation of lysine (which is an amino acid), and has attracted attention as a raw material for nylon 56, nylon 510, polyurethane, urea, etc. As another example, 1,4-diaminobutane (which is a compound called putrescine) is also an organic compound having an unpleasant odor produced during the decomposition of amino acids, and is used as a monomer for preparing polymers such as polyamines. As yet another example, 1,6-diaminohexane (also called hexamethylenediamine (HMD or HMDA)) is an organic compound having a strong amine odor, and is an important raw material in the chemical industry for preparing polyamides, polyureas, or polyurethanes and their copolymers. At the same time, these diaminoalkanes can be obtained in the form of salts such as sulfates and carbonates according to the preparation method. For example, 1,5-pentanediamine adipate can be recovered as crystals by adding adipic acid to the sulfate of 1,5-diaminopentane. Alternatively, the carbonate of 1,5-diaminopentane can be directly recovered as crystals. However, the above preparation methods have low yields, and due to the presence of carbonate as a reaction by-product, when the carbonate is not removed, the product is obtained in the form of a salt. Therefore, in order to remove the salt and obtain pure diaminoalkane, an additional separation / purification method is required, which results in additional costs. Therefore, in order to reduce production costs, a method capable of directly and effectively purifying diaminoalkane by simply and effectively removing carbonate ions from the reaction solution is needed.

[0003] However, existing diaminoalkane purification methods require additional additives for pH control and the like. Therefore, an additional process for separating the additives is required, or problems may occur, such as the formation of impurities and / or fouling in the reactor due to the additives and the like.

[0004] On the other hand, the membrane separation process has the advantages of low energy consumption, simple process, no need for additives, and easy scale-up. Therefore, many studies and demonstrations have been carried out in replacing existing separation processes and improving reactor efficiency. Summary of the Invention

[0005] Technical Problem

[0006] The inventors of the present invention have made efforts to develop a method for effectively removing carbonate from a reaction solution of diaminoalkane based on existing distillation separation methods. As a result, they found that when a membrane contactor separation process using a polymer membrane is combined before a decarboxylation step by distillation, carbonate can be removed more effectively at a relatively low temperature, thus completing the present disclosure.

[0007] [Technical Solution]

[0008] An object of the present disclosure is to provide a method for removing carbon dioxide from a carbonate-containing diaminoalkane solution, the method comprising: a step of passing the carbonate-containing diaminoalkane solution through a membrane module.

[0009] Another object of the present disclosure is to provide a method for preparing a diaminoalkane, the method comprising a step of separating the diaminoalkane from a solution, and removing carbon dioxide from the solution according to the above method.

[0010] [Advantageous Effects]

[0011] According to the method of the present disclosure, since a primary decarboxylation process using a membrane module is combined before a secondary decarboxylation process for removing carbon dioxide by distillation, an effective decarboxylation process can be carried out in an energy-efficient manner at a lower temperature through the primary decarboxylation process, and thus the burden in the secondary decarboxylation process can be significantly reduced. Therefore, problems such as poor mass transfer performance, corrosion of equipment, solvent loss, overflow, foaming, drift, entrainment, etc. caused by a low gas-liquid contact area during carbon dioxide removal due to simple distillation and subsequent equipment expansion do not occur. In addition, in the process using the membrane module, no additives are used, so there is no need for an additional process for separating additives. Therefore, improvement in the economic feasibility and efficiency of the process can be expected. [Description of the Drawings]

[0012] Figure 1 A schematic diagram showing a reactor configuration for a membrane separation process according to an exemplary embodiment of the present invention;

[0013] Figure 2 A graph showing the change in pH in a reaction solution containing 1,5-diaminopentane according to the material of the membrane module and the operation time according to an exemplary embodiment of the present invention;

[0014] Figure 3 A graph showing the change in pH in a reaction solution containing 1,5-diaminopentane according to temperature during the operation of a membrane module made of PSf according to an exemplary embodiment of the present invention;

[0015] Figure 4Shows the pH change in the reaction solution containing 1,4-diaminobutane over time during the membrane separation process according to an exemplary embodiment of the present invention;

[0016] Figure 5 Shows the effect of viscosity control during the operation of the membrane module according to an exemplary embodiment of the present invention; and

[0017] Figure 6 Shows the influence of the configuration of the multi-stage membrane module on the pH change of the reaction solution during the operation time according to an exemplary embodiment of the present invention. [Detailed Embodiments]

[0018] The present disclosure will be described in detail below. At the same time, each description and embodiment disclosed in the present disclosure can also be applied to other descriptions and embodiments. That is, all combinations of the various elements disclosed in the present disclosure fall within the scope of the present disclosure. In addition, the scope of the present disclosure is not limited by the specific descriptions below.

[0019] To achieve the above object, one aspect of the present disclosure provides a method for removing carbon dioxide from a carbonate-containing diaminalkane solution, the method comprising the step of passing the carbonate-containing diaminalkane solution through a membrane module.

[0020] Regarding the method of the present disclosure, 1 equivalent or more of carbon dioxide can be removed through the above process to provide a pure free diaminalkane not in the form of carbonate.

[0021] For this purpose, this process can be carried out in combination with other processes for purifying diaminalkanes, but is not limited thereto. For example, a step of distilling the reaction solution obtained from the above process can be additionally carried out to remove the excess carbon dioxide present in the reaction solution, thereby providing a diaminalkane with a higher purity, but is not limited thereto. This process can be carried out in combination with other methods for purifying diaminalkanes, which are known to those skilled in the art.

[0022] In addition, the method of the present disclosure may further include the step of preparing a carbonate-containing diaminalkane solution as a raw material before the step of removing carbon dioxide using the membrane module, but is not limited thereto.

[0023] For example, the step of preparing a carbonate-containing diaminalkane solution can be carried out by microbial fermentation, bioconversion, or both methods, but is not limited thereto.

[0024] Regarding the method of the present disclosure, the diaminalkane can be 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, but is not limited thereto.

[0025] For example, 1,5-diaminopentane can be produced by the decarboxylation reaction of lysine, specifically by culturing microorganisms to produce lysine, and then subjecting the culture medium to an enzymatic conversion reaction using a decarboxylase or a microorganism into which the enzyme has been introduced. Alternatively, a microorganism producing 1,5-diaminopentane can be prepared by introducing a decarboxylase into a lysine-producing microorganism, and a solution of 1,5-diaminopentane can be obtained by culturing the microorganism. In addition, a solution of 1,5-diaminopentane can also be obtained by various known methods. Similarly, a solution of 1,4-diaminobutane or 1,6-diaminohexane can be prepared by culturing a microorganism producing 1,4-diaminobutane or a microorganism producing 1,6-diaminohexane, and various known methods can also be used. As described above, the diaminoalkane solution prepared by microbial fermentation or enzymatic conversion may contain carbonates.

[0026] For example, it was confirmed that by applying the method of the present disclosure to cadaverine, i.e., 1,5-diaminopentane, which is a representative material of diaminoalkanes, decarboxylation with excellent efficiency is possible under temperature conditions lower than those of simple thermal decarboxylation. In addition, a similar decarboxylation pattern is also possible for 1,4-diaminobutane. Since 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diaminohexane are all known to have similar carbon dioxide adsorption / desorption properties, the method of the present disclosure can be applied to all of these materials.

[0027] As used herein, the term "membrane module" refers to a complete unit composed of a (separation) membrane, a housing, a feed inlet, a concentrate outlet, and a permeate outlet. The membrane module can include various membrane configurations, including but not limited to hollow fiber, flat plate, or tubular membranes.

[0028] The membrane module suitable for the method of the present disclosure preferably has a porous and hydrophobic polymer membrane as the (separation) membrane. The membrane can include, but is not limited to, hollow fiber membranes made of polysulfone (PSf), polyvinylidene fluoride (PVDF), or polypropylene (PP).

[0029] For example, a membrane module having different specifications of hollow fiber membranes made of three polymers can be used for decarboxylation under the same operating conditions. In addition, by comparing the results, decarboxylation with a similar pattern and performance can be carried out regardless of the material of the membrane. This indicates that the rate-determining step in decarboxylation is governed by the slow reaction rate of the bond breakage between the diaminoalkane and carbon dioxide rather than the mass transfer resistance of the membrane. Therefore, since the type of polymer constituting the membrane module does not significantly affect the decarboxylation performance, the characteristics of the material are not limited, and the polymer can be selected from a wide range considering stability under operating conditions.

[0030] Regarding the method of the present disclosure, the step of passing a solution through a membrane module can be carried out by feeding the reaction solution at a flow rate of 10 cm / s to 60 cm / s. For example, this step can be carried out by feeding the reaction solution at a flow rate of 15 cm / s to 55 cm / s, more specifically 20 cm / s to 55 cm / s, 30 cm / s to 55 cm / s, or 32 cm / s to 53 cm / s, but not limited thereto. For example, when the flow rate of the feed is lower than 10 cm / s, it may be difficult to achieve the desired level of decarboxylation efficiency within the desired time due to the delayed reaction. When the flow rate is higher than 60 cm / s, there is a possibility of membrane overload, which reduces the decarboxylation efficiency or damages the membrane durability.

[0031] Regarding the method of the present disclosure, the step of passing a solution through a membrane module can be carried out at a pressure difference of 1 bar to 3 bar, but not limited thereto. The pressure difference can be achieved by applying pressure to the feed reaction solution from the top of the membrane module. For example, this step can be carried out at a pressure difference of 1.2 bar to 3 bar, more specifically 1 bar to 2.5 bar, 1.2 bar to 2.5 bar, or 2 bar to 2.5 bar, but not limited thereto. For example, when the pressure difference is too low, due to insufficient driving force, the mass transfer rate is slow, so the reaction efficiency may be reduced. On the contrary, with a higher pressure difference, a higher decarboxylation efficiency can be expected. However, the membrane is strained due to the high pressure difference, reducing the membrane durability and weakening the long-term stability, and additional equipment, such as pumps, etc., are required to increase the pressure difference, which may cause an economic burden.

[0032] Alternatively, decarboxylation can be induced by applying a vacuum of 1×10 3 torr to 1×10 2 torr to the lower part of the membrane module, but not limited thereto.

[0033] Regarding the method of the present disclosure, the step of passing a solution through a membrane module can be carried out at 80°C to 110°C. For example, the step of passing through the membrane module can be carried out at 85°C to 110°C, specifically 85°C to 100°C, more specifically 87°C to 95°C, but not limited thereto. When the operating temperature is lower than 80°C, decarboxylation may be incomplete, so sufficient carbon dioxide removal may not be achieved. When operating at a high temperature exceeding 110°C, it not only causes excessive energy consumption, but also causes defects due to wetting the membrane and / or damaging the polymer membrane itself.

[0034] Regarding the method of the present disclosure, the step of passing the solution through the membrane module can be carried out for 30 minutes to 10 hours. For example, the step of passing through the membrane module can be carried out for 60 minutes to 8 hours, specifically 1 hour to 5 hours, more specifically 2 hours to 5 hours, or 3 hours to 5 hours, but is not limited thereto. For example, when the reaction time is short and less than 30 minutes, carbon dioxide may not be removed to the desired level because not enough reaction occurs. When the reaction time exceeds 10 hours, no additional decarboxylation occurs after a certain period, and thus unnecessary time and / or energy consumption may be involved.

[0035] The method of the present disclosure is characterized in that after the step of removing carbon dioxide, the pH of the reaction solution increases to 10 or higher, specifically 10.5 or higher. The increase in the pH of the reaction solution indicates that carbon dioxide has been removed from the reaction solution. After the step of passing through the membrane module, in which the membrane module is used, carbon dioxide corresponding to 1 equivalent can be removed, and as a result, the reaction solution can have a pH value of 10 or higher.

[0036] Regarding the method of the present disclosure, the step of passing the solution through the membrane module may further include the step of adding water during the step. The first step is carried out at a high temperature of 80 °C or higher. Therefore, water vapor (which is a gas generated by the evaporation of water contained in the reaction solution) is removed together with carbon dioxide, and the viscosity of the reaction solution increases over time, and thus, mass transfer can be reduced and the reaction rate can be reduced. To solve this problem, water can be additionally supplied to the reaction solution during the reaction in order to promote mass transfer by reducing the viscosity of the reaction solution. Regarding the supplied water, the water vapor separated from the reaction solution by evaporation can be condensed and then reinjected into the reaction solution, but is not limited thereto.

[0037] For example, during the operation time, the rate of increase in pH decreases and approaches a certain level, but when water is resupplied 4 hours after the start of the operation, the pH rises sharply again, and even after 7 hours, the pH continues to increase with time.

[0038] Regarding the method of the present disclosure, the membrane module can include two or more (separate) membranes that are connected in parallel with each other to increase the membrane contact surface. The membrane contact surface can be a factor determining the decarboxylation efficiency.

[0039] For example, when using a module constructed by simply connecting two membranes in parallel, very superior decarboxylation performance can be achieved under the same conditions. This shows that by simply connecting the membranes in parallel to scale up the reaction and improve the performance, the module can thus be applied to large-scale production.

[0040] Regarding the method of the present disclosure, after the step of passing the solution through the membrane module, a step of distilling the solution to remove residual carbonate, a step of removing impurities in the solution, or both of these steps may be further performed. By additional processes, a diaminoalkane with higher purity can be provided. At this time, the process of removing impurities can also be performed by using a distillation method, but is not limited thereto, and this process can be performed without limitation by using methods known in the art.

[0041] Another aspect of the present disclosure provides a method for preparing a diaminoalkane, the method including a step of separating the diaminoalkane from a solution, and removing carbon dioxide from the solution according to the method.

[0042] Regarding the method for preparing a diaminoalkane according to the present disclosure, the step of separating the diaminoalkane can be performed without limitation by using methods known in the art for separating and / or purifying the diaminoalkane.

[0043] [Examples]

[0044] Hereinafter, the present disclosure will be described in more detail with reference to the following exemplary embodiments. However, the following exemplary embodiments are for illustrative purposes only, and the scope of the present disclosure is not intended to be limited by these exemplary embodiments.

[0045] Preparation Example 1: Preparation of a carbonate-containing 1,5-diaminopentane solution by microbial fermentation and enzymatic conversion reaction

[0046] A fermentation broth containing L-lysine was prepared by culturing a microorganism that produces L-lysine. Cells were removed from the fermentation broth, and a solution containing 1,5-diaminopentane was prepared by an enzymatic conversion reaction. At this time, it was confirmed that the solution contained 40% to 60% of carbonate.

[0047] Example 1: Selection of membrane materials and modules

[0048] The membrane material for effective decarboxylation of the 1,5-diaminopentane reaction solution requires high porosity, hydrophobicity, and thermal and chemical stability. As candidates for the material, polysulfone (PSf)-based, polyvinylidene fluoride (PVDF)-based, and polypropylene (PP)-based hollow fiber modules were prepared. The main characteristics of each membrane module are summarized in Table 1 below.

[0049] [Table 1]

[0050] 1 2 3 Material PSf PVDF PP Module Dimensions (diameter / length, cm / cm) 7.7 / 28 3.8 / 35 4 / 65 <![CDATA[Membrane area (m 2 )]]> 1.2 1.0 0.2 Carbon Dioxide Permeability (GPU) 200,000 500 100,000

[0051] *GPU = gas permeation unit,

[0052] Example 2: Decarboxylation performance according to membrane materials and operating conditions

[0053] The pH of the reaction solution is an indirect indicator for determining the amount of carbonate ions remaining in the solution. An increase in the pH of the reaction solution indicates a decrease in carbonate ions in the solution, i.e., the removal of carbonate ions by the reaction. Therefore, a higher pH of the reaction solution after the decarboxylation process indicates better decarboxylation performance. 1000 g of the 1,5-diaminopentane reaction solution prepared from the lysine fermentation broth (initial pH of the reaction solution = 8.30) was placed in a flask, and each membrane module was connected, and after reacting for a predetermined time under each condition by changing the feed flow rate, pressure difference, and operating temperature, the pH was measured. The respective operating conditions and the measured results are shown in Table 2 below. The structure of the reaction apparatus used at this time is schematically shown in Figure 1 as follows.

[0054] [Table 2]

[0055] Module Feed Flow Rate (cm / s) Pressure Difference (bar) Operation Time (h) Operation Temperature (°C) pH after Decarboxylation PSf 32 1.2 4 80 10.60 PSf 32 1.2 4 90 10.86 PSf 53 2.4 5 90 10.96 PSf 53 2.4 5 110 11.30 PSf (two-stage) 53 2.4 5 90 11.45 PVDF 32 1.2 5 90 10.90 PVDF 53 2.4 5 90 11.01 PP 4 1.2 5 80 9.87 PP 16 1.2 5 80 10.20 PP 32 1.2 5 80 10.75 PP 53 2.4 5 90 10.94

[0056] As shown in Table 2, when using the membrane modules of each material, as the feed flow rate, pressure difference, and operating temperature increase, the pH of the reaction solution after decarboxylation increases. This indicates that the mass transfer between the liquid phase and the gas phase increases as the feed flow rate, pressure difference, and operating temperature increase. At the same time, under the same operating conditions (feed flow rate of 53 cm / s, pressure difference of 2.4 bar, operating time of 5 hours, and operating temperature of 90 °C), regardless of the membrane material, similar decarboxylation effects, i.e., similar pH values (10.96, 11.01, and 10.94 for PSf, PVDF, and PP, respectively), are shown, indicating that the rate-determining step in decarboxylation is dominated by the slow reaction rate of the bond breakage between 1,5-diaminopentane and carbon dioxide rather than the mass transfer resistance of the membrane. The same trend was also observed over time. As Figure 3 shown, the pH of the reaction solution increases during the reaction time, and at the same operating time and conditions, similar values are shown regardless of the material of the membrane module.

[0057] Example 3: Decarboxylation performance according to the operating temperature during the operation of the membrane module made of PSf

[0058] As shown in Example 2, all the tested membrane modules showed similar decarboxylation performance under the same conditions without the influence of the material. Therefore, the membrane module made of PSf with the highest glass transition temperature (Tg) in the material to have excellent thermal stability was used to evaluate the decarboxylation performance according to the temperature. In a specific experiment, the pH was measured every hour while allowing the reaction to proceed for up to 5 hours under the operating conditions of a feed flow rate of 53 cm / s and a pressure difference of 2.4 bar at different temperatures, and the results are shown in Figure 3 as follows.

[0059] As Figure 3As shown, the pH increases with increasing operation time under all temperature conditions. At higher operation temperatures, the pH is higher at the same reaction time, indicating better decarboxylation performance. However, when operating at too high a temperature for a long time, accompanying problems may occur, such as membrane wetting phenomena and / or defects in the membrane module. Therefore, it is necessary to achieve the desired decarboxylation performance by controlling the operation time at an appropriate temperature. For example, referring to Figure 3 , the reaction solution reacted at 90 °C for 4 hours shows a similar pH to the reaction solution reacted at 110 °C for 2 hours, indicating that the desired level of decarboxylation performance can be achieved by appropriately controlling the operation temperature and time.

[0060] Example 4: Decarboxylation performance according to the type of diaminoalkane in the reaction solution

[0061] The decarboxylation performance according to temperature was evaluated by applying a membrane module made of PSf to a reaction solution in which carbon dioxide was dissolved and containing 1,4-diaminobutane instead of 1,5-diaminopentane. Specifically, the pH was measured every hour while allowing the reaction to proceed for up to 5 hours under the operating conditions of a feed flow rate of 53 cm / s and a pressure difference of 1.2 bar at 90 °C, and the results are shown in Figure 4 In.

[0062] As Figure 4 shown, the pH of the reaction solution rapidly increased to 10 or more within 1 hour after the start of the reaction. This indicates a decarboxylation performance at a similar level compared to the results of 1,5-diaminopentane shown in Figure 3 , and indicates that the method of removing carbonate using the membrane module of the present disclosure can be applied regardless of the type of diaminoalkane.

[0063] Example 5: Effect of viscosity control during operation

[0064] Decarboxylation through the membrane module was carried out at a high temperature close to 100 °C. Therefore, as the operation time increases, not only carbon dioxide but also some water evaporates, which is also removed together in the form of water vapor, resulting in an increase in the viscosity of the reaction solution and a decrease in the decarboxylation efficiency. To solve this, after a predetermined time, the step of replenishing the reaction solution with water was further carried out, and the pH change was observed while continuously carrying out the reaction, and the results are shown in Figure 5 In.

[0065] As Figure 5As shown in [Figure], when operating under the same conditions (feed flow rate of 53 cm / s, pressure difference of 2.4 bar, operating temperature of 90 °C), the rate of increase in pH decreases over time, shows a rapid recovery when makeup water is supplied after 4 hours of reaction, and the pH continues to increase even when the operating time is extended to 7 hours. This is thought to be because the viscosity of the reaction solution is reduced by water replenishment, and thus mass transfer is promoted. In this regard, the water for replenishment can be reused by cooling the water vapor discharged from the reaction solution by evaporation.

[0066] Example 6: Decarboxylation performance according to the configuration of a two-stage parallel membrane made of PSf

[0067] The effect of increasing the contact surface on the decarboxylation performance was evaluated by using the same two PSf membrane modules connected in parallel in two stages. The evaluation was carried out for 5 hours under the conditions of a feed flow rate of 53 cm / s, a pressure difference of 2.4 bar, and an operating temperature of 90 °C, and the pH value was measured every hour, and the results are shown in Figure 6 [Figure].

[0068] As Figure 6 shown in [Figure], compared with the case of using a single-stage membrane module, when using a two-stage membrane module connected in parallel, it was confirmed that the pH of the reaction solution could increase in a shorter time. This indicates that the separation process can be scaled up proportionally or the efficiency can be improved by a simple method of connecting in parallel.

[0069] Comparative Example 1: Decarboxylation process by simple temperature increase

[0070] To compare the decarboxylation performance between a simple batch system and a membrane separation process, 1000 g of a 1,5-diaminopentane reaction solution was placed in a flask and simply heated to 90 °C without connecting to a membrane contactor. While maintaining for up to 24 hours, the pH of the reaction solution was measured at the time points of 5 hours and 24 hours. As a result, the pH values were measured to be 9.90 and 10.15, respectively. This is because the decarboxylation process using the membrane module of the present disclosure exhibits better decarboxylation performance under the same operating temperature and operating time (when operating for 5 hours under the same conditions using PSf, PVDF, and PP membranes, the pH of the reaction solution is 10.96, 11.01, and 10.94, respectively). Compared with a simple batch decarboxylation system, comparable or higher decarboxylation effects can be achieved at a lower feed flow rate, a lower pressure difference, a lower operating temperature, and / or a shorter operating time, indicating that an energy-efficient process is possible.

[0071] To calculate the decarboxylation rate and mass balance more specifically, as well as the pH change during the decarboxylation process, the reaction solution after decarboxylation was quantitatively analyzed by liquid chromatography, and the results are shown in Table 3 below. In Table 3, the results of the batch decarboxylation process of Comparative Example 1 for 24 hours were compared with the results of Cases 1 to 3 in which the decarboxylation process was carried out for 5 hours using the PP module according to the Example while changing the feed flow rate, pressure difference, and / or operating temperature. As shown in Table 3 below, when using the membrane module, the loss of 1,5-diaminopentane and / or the residual amount of carbonate were reduced, and a significantly higher decarboxylation rate of 2.8 to 3.7 times was observed, even when the short operation time of about 1 / 5 was carried out at an equal or lower operating temperature compared to the batch system.

[0072] [Table 3]

[0073]

[0074] Case 1: PP module, feed of 4 cm / s, pressure difference of 1.2 bar, operation time of 5 hours, operating temperature of 80 °C,

[0075] Case 2: PP module, feed of 16 cm / s, pressure difference of 1.2 bar, operation time of 5 hours, operating temperature of 80 °C,

[0076] Case 3: PP module, feed of 53 cm / s, pressure difference of 2.4 bar, operation time of 5 hours, operating temperature of 90 °C,

[0077] Comparative Example 1: Batch decarboxylation, operation time of 24 hours, operating temperature of 90 °C.

[0078] Based on the above description, those skilled in the art will understand that the present disclosure can be implemented in different specific forms without changing its technical spirit or basic characteristics. In this regard, it should be understood that the above embodiments are not restrictive but illustrative in all respects. The scope of the present disclosure is defined by the appended claims rather than the description preceding the claims, and thus all changes and modifications falling within the scope of the claims or the equivalents of such scope are intended to be covered by the claims.

Claims

1. A method for removing carbon dioxide from a solution containing carbonate-form 1,4-diaminobutane or 1,5-diaminopentane, the method comprising: A step of preparing a solution of carbonate-form 1,4-diaminobutane or 1,5-diaminopentane by microbial fermentation and / or bioconversion, wherein the solution contains 40% to 60% carbonate; A step of passing the solution of carbonate-form 1,4-diaminobutane or 1,5-diaminopentane through a membrane module, wherein an additional step of adding water is further included during the step of passing the solution through the membrane module.

2. The method according to claim 1, wherein the membrane module comprises a hollow fiber membrane made of polysulfone (PSf), polyvinylidene fluoride (PVDF), or polypropylene (PP).

3. The method according to claim 1, wherein the step of passing the solution through the membrane module is carried out by supplying the solution at a flow rate of 10 cm / s to 60 cm / s.

4. The method according to claim 1, wherein the step of passing the solution through the membrane module is carried out with a pressure difference of 1 bar to 3 bar.

5. The method according to claim 1, wherein the step of passing the solution through the membrane module is carried out by applying a vacuum of 1×10 3 Torr to 1×10 2 Torr to the lower part of the membrane module.

6. The method according to claim 1, wherein the step of passing the solution through the membrane module is carried out at 80 °C to 110 °C.

7. The method according to claim 1, wherein the step of passing the solution through the membrane module is carried out for 30 minutes to 10 hours.

8. The method according to claim 1, wherein after the step of passing the solution through the membrane module, the pH of the solution increases to 10 or higher.

9. The method according to claim 1, wherein the membrane module comprises two or more membranes connected in parallel to each other.

10. The method according to claim 1, after the step of passing the solution through the membrane module, further comprises: A step of distilling the solution to remove residual carbonate, a step of removing impurities in the solution, or both of the steps.

11. A method for preparing 1,4-diaminobutane or 1,5-diaminopentane, the method comprising a step of separating 1,4-diaminobutane or 1,5-diaminopentane from a solution, Removing carbon dioxide from the solution according to the method of claim 1.

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