Method and device for the production of l-magnesium aspartate by selective ion replacement electrodialysis

Abstract

The present application belongs to the technical field of pharmaceutical production, and particularly relates to a method and device for preparing L-magnesium aspartate by selective ion replacement electrodialysis. The present application uses a selective ion replacement electrodialysis device to convert an intermediate product of industrial L-aspartate production, L-ammonium aspartate, to prepare L-magnesium aspartate. The selective permeability of the ion exchange membrane is used to realize the replacement of cations in two different electrolytes, so that the ions are recombined to form L-magnesium aspartate. Thus, the deficiencies of the prior art process of first preparing L-aspartate and then preparing L-magnesium aspartate are avoided. The purity of the L-aspartate prepared according to the present method and the conversion rate of the L-ammonium aspartate both reach more than 97%, and the energy consumption is low. The L-magnesium aspartate product with high purity can be quickly prepared, and the by-product ammonium sulfate can also be obtained in the product chamber 2, thereby improving the economic benefits of the process and having important industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical production technology, and specifically relates to a method and apparatus for preparing L-aspartic acid magnesium by selective ion substitution electrodialysis. Background Technology

[0002] The existing production process for L-aspartic magnesium utilizes L-aspartic acid and magnesium-containing inorganic substances (such as magnesium carbonate, magnesium oxide, or magnesium hydroxide) as raw materials for synthesis. L-Aspartic acid, as one of the raw materials for synthesizing L-aspartic magnesium, is commonly prepared using a combination of chemical synthesis and fermentation. The method for preparing L-aspartic acid, as described in the journal *Tianjin Chemical Industry*, January 2015, Vol. 29, No. 1, pp. 13-15, uses maleic acid as a raw material, converting it to fumaric acid under inorganic catalyst and strong acid conditions. Fumaric acid reacts with ammonia to form ammonium fumarate, which is then converted to ammonium L-aspartic acid under the action of L-aspartate transaminase. Sulfuric acid is added to the reaction solution to cause isoelectric precipitation of L-aspartic acid, yielding the final L-aspartic acid product. A method for preparing magnesium L-aspartate from L-aspartic acid, proposed in patent CN102875402A, involves using magnesium carbonate, magnesium oxide, or magnesium hydroxide as raw materials, reacting them at 70-80℃ with water as a solvent. After the reaction, the pH of the reaction solution is adjusted to 6.0-7.5, the solution is decolorized, filtered, and concentrated to supersaturation to obtain a saturated solution. The supersaturated solution is then dried using a vacuum freeze dryer to obtain the finished product. This method first requires the preparation of L-aspartic acid, which is then used as a raw material to prepare magnesium L-aspartate. However, the entire preparation process of L-aspartic acid is lengthy and cumbersome. The addition of strong acid to precipitate L-aspartic acid can also cause corrosion to the equipment. Furthermore, the production of magnesium L-aspartate requires heating to 70-80℃, resulting in high energy consumption and increased costs, which does not align with the principles of green production.

[0003] Selective ion-substitution electrodialysis is a highly efficient, low-energy-consumption, and environmentally friendly reaction separation technique that can achieve ion replacement reactions that cannot spontaneously occur under conventional conditions. However, there are currently no reports on the conversion of L-aspartic ammonium to prepare L-aspartic magnesium. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a method for preparing L-aspartate magnesium using selective ion substitution electrodialysis. The method employs a selective ion substitution electrodialysis apparatus and includes the following steps:

[0005] The membrane stacks in the selective ion replacement electrodialysis device are arranged according to a predetermined pattern.

[0006] Based on the membrane stack arrangement, an L-aspartic acid ammonium solution is introduced into the feed chamber 1 or the product chamber 1, a magnesium sulfate solution is introduced into the feed chamber 2, deionized water is introduced into the product chamber 2, and a sodium sulfate solution is introduced into the anode chamber and the cathode chamber.

[0007] A direct current is applied to both ends of the selective ion substitution electrodialysis device to carry out the reaction according to the set mode. After the reaction, the target product, magnesium L-aspartate, is obtained in product chamber 1.

[0008] Furthermore, the membrane stack arrangement in the selective ion replacement electrodialysis device is configured as follows: anode - anode chamber - [anion exchange membrane - feed chamber 2 - cation exchange membrane 1 - feed chamber 1 / product chamber 1 - cation exchange membrane 2 - product chamber 2] n -Anion exchange membrane-cathode chamber;

[0009] Where n is the number of repeating units, and n is 1-1000.

[0010] Furthermore, the products also include ammonium sulfate, a byproduct obtained in product chamber 2.

[0011] Furthermore, the concentration of the L-aspartic acid ammonium solution introduced into the feed chamber 1 or product chamber 1 is 0.1-1.0 mol / L.

[0012] Furthermore, the concentration of the magnesium sulfate solution introduced into the feed chamber 2 is 0.1-0.6 mol / L.

[0013] Furthermore, the concentration of the sodium sulfate solution introduced into the anode chamber and the cathode chamber is 0.1-0.6 mol / L.

[0014] Furthermore, when the selective ion replacement electrodialysis device is in operation, it adopts a constant pressure operation mode, and the membrane pair voltage of each repeating unit is 0.1-3V.

[0015] Furthermore, the anion exchange membrane is an AMX anion exchange membrane;

[0016] The cation exchange membrane 1 is a CMX cation exchange membrane;

[0017] The cation exchange membrane 2 is a CIMS cation exchange membrane.

[0018] On the other hand, the present invention also proposes a selective ion substitution electrodialysis device for preparing the L-aspartic acid magnesium;

[0019] The device includes an anode plate, a cathode plate, and an ion exchange membrane;

[0020] An anode chamber is formed between the anode plate and the adjacent ion exchange membrane, and a cathode chamber is formed between the cathode plate and the anion exchange membrane. The anode chamber and the cathode chamber are connected in series. Anion exchange membrane-feed chamber 2-cation exchange membrane 1-feed chamber 1 / product chamber 1-cation exchange membrane 2-product chamber 2 are arranged sequentially from the anode chamber to the cathode chamber.

[0021] The beneficial effects of this invention are:

[0022] This invention utilizes a selective ion substitution electrodialysis device to convert L-aspartic acid ammonium, an intermediate product from the industrial production of L-aspartic acid, into magnesium L-aspartic acid. The selective ion substitution electrodialysis device comprises a feed chamber 2, a feed chamber 1 / product chamber 1, and a product chamber. Under the action of a DC electric field, the selective permeability of the ion exchange membrane enables the substitution of cations in two different electrolytes, allowing the ions to recombine and generate magnesium L-aspartic acid. This avoids the shortcomings of existing processes that first prepare L-aspartic acid and then magnesium L-aspartic acid. Furthermore, the purity of magnesium L-aspartic acid prepared according to this method reaches over 97%, and the conversion rate of L-aspartic acid ammonium is high, also exceeding 97%. It also features low energy consumption and can rapidly produce high-purity magnesium L-aspartic acid. Simultaneously, ammonium sulfate byproduct is also obtained in product chamber 2, improving the economic efficiency of the process and possessing significant industrial application value.

[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart of the method for preparing L-aspartic acid magnesium by selective ion substitution electrodialysis proposed in an embodiment of the present invention is shown;

[0026] Figure 2 A schematic diagram illustrating the principle of selective ion substitution electrodialysis for the preparation of magnesium L-aspartate in an embodiment of the present invention is shown. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention proposes a method for selectively preparing magnesium L-aspartate via ion-substitution electrodialysis, as follows: Figure 1 As shown, the method employs a selective ion replacement electrodialysis device and specifically includes the following steps:

[0029] The membrane stacks in the selective ion-substitution electrodialysis device are arranged according to a predetermined pattern; the membrane stack arrangement in the selective ion-substitution electrodialysis device is as follows: anode - anode chamber - [anion exchange membrane - feed chamber 2 - cation exchange membrane 1 - feed chamber 1 / product chamber 1 - cation exchange membrane 2 - product chamber 2] n -Anion exchange membrane-cathode chamber;

[0030] Where n is the number of repeating units, and n is 1-1000;

[0031] Furthermore, the anion exchange membrane is an AMX anion exchange membrane, which allows anions to migrate in the solution while blocking cations; the cation exchange membrane 1 is a CMX cation exchange membrane, which allows cations to migrate in the solution while blocking anions; and the cation exchange membrane 2 is a CIMS cation exchange membrane, which allows monovalent cations to migrate in the solution while blocking polyvalent cations and anions.

[0032] Based on the membrane stack arrangement, an L-aspartic acid ammonium solution with a concentration of 0.1-1.0 mol / L is introduced into the feed chamber 1 or the product chamber 1, a magnesium sulfate solution with a concentration of 0.1-0.6 mol / L is introduced into the feed chamber 2, deionized water is introduced into the product chamber 2, and a sodium sulfate solution with a concentration of 0.1-0.6 mol / L is introduced into the anode chamber and the cathode chamber.

[0033] A direct current is applied to both ends of the selective ion substitution electrodialysis device to carry out the reaction according to the set mode. After the reaction, the target product L-aspartic acid magnesium is obtained in product chamber 1 and the by-product ammonium sulfate is obtained in product chamber 2. When the selective ion substitution electrodialysis device is running, a constant voltage operation mode is adopted, and the operating voltage is 0.1-3V per repeating unit. The sum of the voltages of each repeating unit plus the electrode chamber voltage equals the membrane stack voltage. In the following examples, the membrane stack voltage is used.

[0034] The selective ion substitution electrodialysis device includes an anode plate, a cathode plate, and an ion exchange membrane;

[0035] An anode chamber is formed between the anode plate and the adjacent ion exchange membrane, and a cathode chamber is formed between the cathode plate and the anion exchange membrane. The anode chamber and the cathode chamber are connected in series. Anion exchange membrane-feed chamber 2-cation exchange membrane 1-feed chamber 1 / product chamber 1-cation exchange membrane 2-product chamber 2 are arranged sequentially from the anode chamber to the cathode chamber.

[0036] The above method will be illustrated with specific examples below.

[0037] Example 1

[0038] This embodiment uses, as follows: Figure 1 The selective ion-substitution electrodialysis apparatus shown has membrane stacks arranged sequentially from anode to cathode as follows: anode - anode chamber - [anion exchange membrane - feed chamber 2 - cation exchange membrane 1 - feed chamber 1 / product chamber 1 - cation exchange membrane 2 - product chamber 2] n - Anion exchange membrane - Cathode chamber, with a repeating unit quantity of 2. The anode and cathode materials in the membrane stack are corrosion-resistant titanium coated with ruthenium. Each compartment between adjacent ion exchange membranes is composed of a mesh with flow channels, and the thickness of a single mesh is 0.8 mm. The anion exchange membrane used in the membrane stack is the standard anion exchange membrane AMX manufactured by ASTOM Corporation, Japan. Cation exchange membrane 1 and cation exchange membrane 2 are the standard cation exchange membrane CMX and the monovalent cation selective membrane CIMS manufactured by ASTOM Corporation, Japan, respectively. The effective area of ​​a single membrane is 189 cm². 2 (9cm×21cm).

[0039] The anode and cathode plates form an anode chamber and a cathode chamber with the adjacent ion exchange membrane. These chambers are connected in series. A 500 mL solution of 0.30 mol / L sodium sulfate is introduced as the electrode solution. A 500 mL solution of 0.30 mol / L magnesium sulfate is introduced into feed chamber 2. A 500 mL solution of 0.54 mol / L ammonium L-aspartate is introduced into feed chamber 1 and product chamber 1. 500 mL of deionized water is introduced into product chamber 2. During the experiment, the linear velocity of the solution flow in each chamber is 3 cm / s. A constant voltage operating mode is used, with the membrane stack voltage set to 5 V.

[0040] During the production process, the process ended when the conductivity of feed chamber 2 dropped to 0.50 mS / cm, with a running time of 244 minutes and a membrane voltage of 0.6-0.7 V. Ultimately, the concentration of ammonium sulfate in product chamber 2 was 0.22 mol / L; the concentration of magnesium L-aspartate in feed chamber 1 / product chamber 1 was 0.25 mol / L, the conversion rate of ammonium L-aspartate was 98.2%, the energy consumption for producing magnesium L-aspartate was 0.43 kWh / kg, and its purity reached 98.1%.

[0041] Example 2

[0042] The selective ion substitution electrodialysis device used in this embodiment is the same as that in Embodiment 1.

[0043] The anode and cathode plates form an anode chamber and a cathode chamber with the adjacent membranes, respectively. These chambers are connected in series and 500 mL of 0.30 mol / L sodium sulfate solution is introduced as the electrode solution. Feed chamber 2 is supplied with 500 mL of 0.30 mol / L magnesium sulfate solution. Feed chamber 1 and product chamber 1 are supplied with 500 mL of 0.54 mol / L L-aspartic acid ammonium solution. Product chamber 2 is supplied with 500 mL of deionized water. During the experiment, the linear velocity of the solution flow in each chamber is 3 cm / s. A constant voltage operating mode is used, with the membrane stack voltage set to 6 V.

[0044] During the production process, the process ended when the conductivity of feed chamber 2 dropped to 0.50 mS / cm, with a running time of 160 minutes and a membrane voltage of 0.8-1.0 V. Ultimately, the concentration of ammonium sulfate in product chamber 2 was 0.21 mol / L; the concentration of magnesium L-aspartate in feed chamber 1 / product chamber 1 was 0.26 mol / L, the conversion rate of ammonium L-aspartate was 98.7%, the energy consumption for producing magnesium L-aspartate was 0.34 kWh / kg, and its purity reached 98.7%.

[0045] Example 3

[0046] The selective ion substitution electrodialysis device used in this embodiment is the same as that in Embodiment 1.

[0047] The anode and cathode plates form an anode chamber and a cathode chamber with the adjacent membranes, respectively. These chambers are connected in series and 500 mL of 0.30 mol / L sodium sulfate solution is introduced as the electrode solution. Feed chamber 2 is supplied with 500 mL of 0.30 mol / L magnesium sulfate solution. Feed chamber 1 and product chamber 1 are supplied with 500 mL of 0.54 mol / L L-aspartic acid ammonium solution. Product chamber 2 is supplied with 500 mL of deionized water. During the experiment, the linear velocity of the solution flow in each chamber is 3 cm / s. A constant voltage operating mode is used, with the membrane stack voltage set to 7 V.

[0048] During the production process, the process ended when the conductivity of feed chamber 2 dropped to 0.50 mS / cm, with a running time of 105 minutes and a membrane voltage of 0.9-1.2 V. Ultimately, the concentration of ammonium sulfate in product chamber 2 was 0.23 mol / L; the concentration of magnesium L-aspartate in feed chamber 1 / product chamber 1 was 0.26 mol / L, the conversion rate of ammonium L-aspartate was 97.9%, the energy consumption for producing magnesium L-aspartate was 0.26 kWh / kg, and its purity reached 97.8%.

[0049] Example 4

[0050] The selective ion substitution electrodialysis device used in this embodiment is the same as that in Embodiment 1.

[0051] The anode and cathode plates form an anode chamber and a cathode chamber with the adjacent membranes, respectively. These chambers are connected in series and 500 mL of 0.30 mol / L sodium sulfate solution is introduced as the electrode solution. Feed chamber 2 is supplied with 500 mL of 0.40 mol / L magnesium sulfate solution. Feed chamber 1 and product chamber 1 are supplied with 500 mL of 0.54 mol / L L-aspartic acid ammonium solution. Product chamber 2 is supplied with 500 mL of deionized water. During the experiment, the linear velocity of the solution flow in each chamber is 3 cm / s. A constant voltage operating mode is used, with the membrane stack voltage set to 6 V.

[0052] During the production process, the process ended when the conductivity of feed chamber 2 dropped to 9.70 mS / cm, with a running time of 85 minutes and a membrane voltage of 0.8-1.0 V. Ultimately, the concentration of ammonium sulfate in product chamber 2 was 0.22 mol / L; the concentration of magnesium L-aspartate in feed chamber 1 / product chamber 1 was 0.26 mol / L, the conversion rate of ammonium L-aspartate was 98.1%, the energy consumption for producing magnesium L-aspartate was 0.29 kWh / kg, and its purity reached 98.0%.

[0053] Example 5

[0054] The selective ion substitution electrodialysis device used in this embodiment is the same as that in Embodiment 1.

[0055] The anode and cathode plates form an anode chamber and a cathode chamber with the adjacent membranes, respectively. These chambers are connected in series and 500 mL of 0.30 mol / L sodium sulfate solution is introduced as the electrode solution. 500 mL of 0.50 mol / L magnesium sulfate solution is introduced into feed chamber 2. 500 mL of 0.80 mol / L L-aspartic acid ammonium solution is introduced into feed chamber 1 / product chamber 1. 500 mL of deionized water is introduced into product chamber 2. During the experiment, the linear velocity of the solution flow in each chamber is 3 cm / s. A constant voltage operating mode is used, with the membrane stack voltage set to 6 V.

[0056] During the production process, the process ended when the conductivity of feed chamber 2 dropped to 7.50 mS / cm, with a running time of 105 minutes and a membrane voltage of 0.8-1.0 V. Ultimately, the concentration of ammonium sulfate in product chamber 2 was 0.34 mol / L; the concentration of magnesium L-aspartate in feed chamber 1 / product chamber 1 reached 0.37 mol / L, the conversion rate of ammonium L-aspartate was 97.1%, the energy consumption for producing magnesium L-aspartate was 0.29 kWh / kg, and its purity reached 97.0%.

[0057] The results of preparing L-aspartic acid magnesium using an ion-exchange membrane reactor in Examples 1-5 are shown in Table 1:

[0058] Table 1 Reaction results of each embodiment

[0059]

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the production of L-magnesium aspartate by selective ion-replacement electrodialysis, characterized in that, The method uses a selective ion-replacement electrodialysis device, comprising the following steps: The membrane stack arrangement in the selective ion replacement electrodialysis device is arranged according to a set arrangement; the membrane stack arrangement in the selective ion replacement electrodialysis device is sequentially arranged as: anode-anode chamber-[anion exchange membrane-feed chamber 2-cation exchange membrane 1-feed chamber 1 / product chamber 1-cation exchange membrane 2-product chamber 2] n -anion exchange membrane-cathode chamber; wherein n is the number of repeating units, n is 1-1000; Based on the membrane stack arrangement, L-aspartic acid ammonium solution is introduced into feed chamber 1 or product chamber 1, magnesium sulfate solution is introduced into feed chamber 2, deionized water is introduced into product chamber 2, and sodium sulfate solution is introduced into the anode chamber and the cathode chamber; A direct current is applied at both ends of the selective ion-replacement electrodialysis device to carry out the reaction according to the set mode, and after the reaction, the target product L-magnesium aspartate is obtained in the product chamber 1.

2. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, The product also includes the by-product ammonium sulfate obtained in the product chamber 2.

3. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, The concentration of the L-aspartic acid ammonium solution introduced into the feed chamber 1 or the product chamber 1 is 0.1-1.0 mol / L.

4. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, The concentration of the magnesium sulfate solution introduced into the feed chamber 2 is 0.1-0.6 mol / L.

5. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, The concentration of the sodium sulfate solution introduced into the anode chamber and the cathode chamber is 0.1-0.6 mol / L.

6. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, When the selective ion-replacement electrodialysis device is in operation, a constant voltage operation mode is used, and the voltage of each repeated unit of the membrane pair is 0.1-3 V.

7. The method for preparing L-magnesium aspartate by selective ion-replacement electrodialysis according to claim 1, characterized in that, The anion exchange membrane is an AMX anion exchange membrane; The cation exchange membrane 1 is a CMX cation exchange membrane; The cation exchange membrane 2 is a CIMS cation exchange membrane.

8. A selective ion-replacement electrodialysis unit, characterized by The device is used for preparing L-magnesium aspartate according to any one of claims 1-7; The device comprises an anode plate, a cathode plate, and ion exchange membranes; The anode plate and the adjacent ion exchange membrane form an anode chamber, the cathode plate and the anion exchange membrane form a cathode chamber, and the anode chamber and the cathode chamber are connected in series; the anion exchange membrane-feed chamber 2-cation exchange membrane 1-feed chamber 1 / product chamber 1-cation exchange membrane 2-product chamber 2 are sequentially arranged between the anode chamber and the cathode chamber.

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