A method for recovering solvent and urea sulfate from ornithine crystallization mother liquor

Abstract

The application belongs to the technical field of chemical and pharmaceutical production, and discloses a method for recovering solvent and urea sulfate from ornithine crystallization mother liquor. The method comprises the following steps: adding sulfuric acid into the ornithine crystallization mother liquor to adjust pH, and then performing electrodialysis to obtain a dilute phase and a concentrated phase; performing rectification on the dilute phase, and obtaining the solvent by taking out the vapor obtained from the top of the tower after reflux; and sequentially performing vacuum concentration and spray drying on the concentrated phase to obtain urea sulfate solid. The urea in the ornithine crystallization mother liquor is neutralized by adding sulfuric acid to generate urea sulfate, the generated urea sulfate is removed by electrodialysis, and the solvent product obtained by rectification again can meet the standard requirements, and the product quality is more stable.

Description

Technical Field

[0001] This invention relates to the field of chemical and pharmaceutical production technology, and in particular to a method for recovering solvent and urea sulfate from ornithine crystallization mother liquor. Background Technology

[0002] Ornithine is a non-essential amino acid with multiple roles in human metabolism. It primarily participates in the urea cycle, ammonia metabolism, and liver protection, and may also influence growth hormone secretion and exercise recovery. Ornithine is a key component of the urea cycle, working synergistically with citrulline to help convert toxic ammonia into urea, which is ultimately excreted through the kidneys. This process is crucial for preventing hyperammonemia (excessively high ammonia concentration in the blood), especially important for patients with liver disease or metabolic abnormalities. In vivo, ornithine mainly participates in the urea cycle, playing a vital role in the excretion of ammonia nitrogen. In medicine, besides being used as a reagent and injection, ornithine is often used with arginine in the formulation of effervescent beverages to relieve fatigue. In recent years, the application of ornithine in the food and pharmaceutical industries has become increasingly widespread.

[0003] The ornithine preparation process involves hydrolyzing arginine into L-ornithine and urea using an enzyme as a catalyst. The resulting product is obtained through solvent crystallization, separation, washing, and drying. The mother liquor mainly consists of water, urea, and solvent. To reduce production costs, meet environmental compliance requirements, reduce hazardous waste emissions, improve material utilization, and support green manufacturing and sustainable development goals, the mother liquor is recycled. Traditional processes involve direct distillation of the mother liquor, utilizing boiling point differences for separation. However, this direct distillation of the mother liquor contains urea, which decomposes upon heating to produce ammonia that dissolves in the solvent, hindering solvent separation and purification; consequently, it affects the quality of the recovered product. Summary of the Invention

[0004] The purpose of this invention is to provide a method for recovering solvent and urea sulfate from ornithine crystallization mother liquor, thereby solving the aforementioned problems existing in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for recovering solvent and urea sulfate from ornithine crystallization mother liquor, comprising the following steps: Sulfuric acid was added to the ornithine crystallization mother liquor to adjust the pH, resulting in a mixed solution. The mixture was subjected to electrodialysis to obtain a light phase and a concentrated phase; The light phase is distilled, and the vapor obtained from the top of the column during the distillation process is refluxed and collected to obtain the solvent. The concentrated phase was successively concentrated under reduced pressure and spray dried to obtain solid urea sulfate, thus completing the recovery of solvent and urea sulfate from ornithine crystallization mother liquor.

[0006] Preferably, the ornithine crystallization mother liquor includes a solvent and urea.

[0007] Preferably, sulfuric acid is added to adjust the pH to 4-7.

[0008] Preferably, the conductivity of the pale phase is <100 μs / cm.

[0009] Preferably, the distillation conditions include: a bottom temperature of 70~110℃, a pressure of 0~20KPa, and a reflux ratio of 1.1~2 times the minimum reflux ratio.

[0010] Preferably, the temperature for vacuum concentration is 60~100℃.

[0011] Preferably, the final concentration of the vacuum concentration is 30-60%.

[0012] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention generates urea sulfate by reacting sulfuric acid with urea in the mother liquor of ornithine crystallization. The generated urea sulfate is then removed by electrodialysis and further distilled to obtain a solvent product that meets the standard requirements and has more stable quality. Detailed Implementation

[0013] This invention provides a method for recovering solvent and urea sulfate from ornithine crystallization mother liquor, comprising the following steps: Sulfuric acid was added to the ornithine crystallization mother liquor to adjust the pH, resulting in a mixed solution. The mixture was subjected to electrodialysis to obtain a light phase and a concentrated phase; The light phase is distilled, and the vapor obtained from the top of the column during the distillation process is refluxed and collected to obtain the solvent. The concentrated phase was successively concentrated under reduced pressure and spray dried to obtain solid urea sulfate, thus completing the recovery of solvent and urea sulfate from ornithine crystallization mother liquor.

[0014] In this invention, the ornithine crystallization mother liquor includes a solvent and urea.

[0015] In this invention, the solvent in the ornithine crystallization mother liquor is preferably methanol or ethanol, and more preferably methanol.

[0016] In this invention, the addition of sulfuric acid to adjust the pH is preferably to 4-7, more preferably 5-6.5, and even more preferably 6.

[0017] In this invention, the conductivity of the pale phase is preferably <100 μs / cm, more preferably <90 μs / cm, and even more preferably 80 μs / cm.

[0018] In this invention, the distillation conditions include: a reboiler temperature preferably of 70-110°C, more preferably of 90-110°C, and even more preferably of 105°C; a pressure preferably of 0-20 kPa, more preferably of 5-15 kPa, and even more preferably of 10 kPa; and a reflux ratio preferably of 1.1-2 times the minimum reflux ratio, more preferably of 1.1-1.5 times, and even more preferably of 1.1 times.

[0019] In this invention, the temperature for vacuum concentration is preferably 60~100℃, more preferably 65~80℃, and even more preferably 70℃.

[0020] In this invention, the endpoint concentration of the vacuum concentration is preferably 30-60%, more preferably 35-50%, and even more preferably 40%.

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0022] Example 1

[0023] (1) Take 5000 mL of ornithine crystallization mother liquor (containing 70% solvent and 2% urea), add sulfuric acid to adjust the pH of the solution to 6.0, and obtain a mixed solution; (2) The mixed solution is desalinated by electrodialysis. During electrodialysis, sulfuric acid is added to the dilute phase to control the pH of the solution at 6.0, and the current is adjusted to 20 mA / cm. 2 Electrodialysis was stopped when the single membrane voltage was 1.5V until the conductivity of the light phase was detected to be 80μs / cm, thus obtaining the light and concentrated phases. (3) Control the temperature of the column bottom to 105℃, the pressure to 10KPa, and the reflux ratio to 1.1 of the minimum reflux ratio. Distill the light phase and collect the vapor obtained from the top of the column after reflux to obtain the solvent product. (4) Control the temperature to 70℃ and the vacuum to ≤-0.06MPa, concentrate the concentrated phase under reduced pressure to a concentration of 40%, and then spray dry to obtain solid urea sulfate.

[0024] The solvent product was tested and found to contain ammonium salts <0.02%, sulfates <0.020%, and urea sulfate solid was a white granular particle.

[0025] Comparative Example 1

[0026] (1) Take 5000 mL of ornithine crystallization mother liquor (same as in Example 1), add sulfuric acid to adjust the pH of the solution to 3.5, and obtain a mixed solution; (2) The mixture was desalted by electrodialysis (see Example 1 for electrodialysis parameters) until the conductivity of the light phase was detected to be 80 μs / cm, and then electrodialysis was stopped to obtain the light phase and the concentrated phase; (3) Control the temperature of the column bottom to 105℃, the pressure to 10KPa, and the reflux ratio to 1.1 of the minimum reflux ratio. Distill the light phase and collect the vapor obtained from the top of the column after reflux to obtain the solvent product. (4) Control the temperature to 70℃ and the vacuum to ≤-0.06MPa, concentrate the concentrated phase under reduced pressure to a concentration of 40%, and then spray dry to obtain solid urea sulfate.

[0027] The solvent product was tested and found to contain ammonium salts <0.02%, sulfates >0.020%, and urea sulfate solid was a white granular particle.

[0028] Comparative Example 2

[0029] (1) Take 5000 mL of ornithine crystallization mother liquor (same as in Example 1), add sulfuric acid to adjust the pH of the solution to 6.0, and obtain a mixed solution; (2) The mixture was desalted by electrodialysis (see Example 1 for electrodialysis parameters) until the conductivity of the light phase was 120 μs / cm, and then electrodialysis was stopped to obtain the light phase and the concentrated phase; (3) Control the temperature of the column bottom to 105℃, the pressure to 10KPa, and the reflux ratio to 1.1 of the minimum reflux ratio. Distill the light phase and collect the vapor obtained from the top of the column after reflux to obtain the solvent product. (4) Control the temperature to 70℃ and the vacuum to ≤-0.06MPa, concentrate the concentrated phase under reduced pressure to a concentration of 40%, and then spray dry to obtain solid urea sulfate.

[0030] The solvent product was tested and found to contain ammonium salt >0.02%, sulfate <0.020%, and urea sulfate solid was a white granular particle.

[0031] Comparative Example 3

[0032] (1) Take 5000 mL of ornithine crystallization mother liquor (same as in Example 1), add sulfuric acid to adjust the pH of the solution to 6.0, and obtain a mixed solution; (2) The mixture was desalted by electrodialysis (see Example 1 for electrodialysis parameters) until the conductivity of the light phase was detected to be 80 μs / cm, and then electrodialysis was stopped to obtain the light phase and the concentrated phase; (3) Control the temperature of the column bottom to 105℃, the pressure to 10KPa, and the reflux ratio to 1.1 of the minimum reflux ratio. Distill the light phase and collect the vapor obtained from the top of the column after reflux to obtain the solvent product. (4) Control the temperature to 70℃ and the vacuum to ≤-0.06MPa, and concentrate the concentrated phase to 70% under reduced pressure. Due to the high concentration, spraying cannot be carried out during the urea sulfate recovery process.

[0033] The solvent finished product test showed ammonium salt <0.02% and sulfate <0.020%. Due to the high concentration, spraying was not possible during the urea sulfate recovery process.

[0034] Comparative Example 4

[0035] (1) Take 5000 mL of ornithine crystallization mother liquor (same as in Example 1), add sulfuric acid to adjust the pH of the solution to 6.0, and obtain a mixed solution; (2) The mixture was desalted by electrodialysis (see Example 1 for electrodialysis parameters) until the conductivity of the light phase was detected to be 80 μs / cm, and then electrodialysis was stopped to obtain the light phase and the concentrated phase; (3) Control the temperature of the column bottom at 65℃, the pressure at 10KPa, and the reflux ratio at 1.1 of the minimum reflux ratio to distill the light phase. The vapor obtained at the top of the column is collected after reflux to obtain the solvent product. (4) Control the temperature to 70℃ and the vacuum to ≤-0.06MPa, concentrate the concentrated phase under reduced pressure to a concentration of 40%, and then spray dry to obtain solid urea sulfate.

[0036] The solvent product test showed ammonium salt <0.02%, sulfate <0.020%, and urea sulfate solid as white granular particles. However, the low temperature in the distillation column bottom resulted in a long time and reduced efficiency.

[0037] Comparative Example 5

[0038] (1) Take 5000 mL of ornithine crystallization mother liquor (same as in Example 1), add sulfuric acid to adjust the pH of the solution to 6.0, and obtain a mixed solution; (2) The mixture was desalted by electrodialysis (see Example 1 for electrodialysis parameters) until the conductivity of the light phase was detected to be 80 μs / cm, and then electrodialysis was stopped to obtain the light phase and the concentrated phase; (3) Control the temperature of the column bottom to 90℃, the pressure to 10KPa, and the reflux ratio to 1.1 of the minimum reflux ratio. Distill the light phase and collect the vapor obtained from the top of the column after reflux to obtain the solvent product. (4) Control the temperature to 55℃ and the vacuum to ≤-0.06MPa, concentrate the concentrated phase under reduced pressure to a concentration of 40%, and then spray dry to obtain solid urea sulfate.

[0039] The solvent product test showed ammonium salt <0.02% and sulfate <0.020%. Urea sulfate solid was a white granular particle, but the low vacuum concentration temperature resulted in a long time and affected efficiency.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering solvent and urea sulfate from ornithine crystallization mother liquor, characterized in that, Includes the following steps: Sulfuric acid was added to the ornithine crystallization mother liquor to adjust the pH, resulting in a mixed solution. The mixture was subjected to electrodialysis to obtain a light phase and a concentrated phase; The light phase is distilled, and the vapor obtained from the top of the column during the distillation process is refluxed and collected to obtain the solvent. The concentrated phase was successively concentrated under reduced pressure and spray dried to obtain solid urea sulfate, thus completing the recovery of solvent and urea sulfate from ornithine crystallization mother liquor.

2. The method according to claim 1, characterized in that, The ornithine crystallization mother liquor includes a solvent and urea.

3. The method according to claim 1, characterized in that, The pH is adjusted to 4-7 by adding sulfuric acid.

4. The method according to claim 1, characterized in that, The conductivity of the pale phase is <100 μs / cm.

5. The method according to claim 1, characterized in that, The distillation conditions include: a reboiler temperature of 70~110℃, a pressure of 0~20KPa, and a reflux ratio of 1.1~2 times the minimum reflux ratio.

6. The method according to claim 1, characterized in that, The temperature for vacuum concentration is 60~100℃.

7. The method according to claim 1, characterized in that, The final concentration of the vacuum concentration is 30-60%.