Process method for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride by taking corn soaking water as raw material

Abstract

The invention relates to the technical field of corn soaking water treatment, in particular to a process method for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride by taking corn soaking water as a raw material, which comprises the following steps: adsorbing supernate obtained by standing and settling the corn soaking water through a resin column, then performing desorption and concentration, and performing vacuum concentration on the obtained trapped fluid to obtain the inositol and magnesium ammonium phosphate. The method comprises the following steps: collecting a concentrated solution, carrying out enzymolysis treatment on the collected concentrated solution, carrying out vacuum concentration on the filtered enzymatic hydrolysate, enabling the obtained concentrated solution to enter a chromatographic separation system, then eluting, respectively collecting an inositol phase and a salt phase, and carrying out secondary crystallization, filtration and drying on the collected inositol phase to obtain an inositol product, treating the collected salt phase to obtain a magnesium ammonium phosphate product; and adjusting the pH value of the collected filtrate to be acidic, and carrying out vacuum concentration, centrifugal separation and drying to obtain an ammonium chloride product. According to the process method, the inositol product and the magnesium ammonium phosphate product with high yield, high yield and high purity can be obtained, and the recovery of ammonium chloride is realized.

Description

Technical Field

[0001] This invention relates to the field of corn soaking water treatment technology, and in particular to a process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water as raw material. Background Technology

[0002] Corn soaking water is wastewater generated during the corn soaking process in corn starch production. It is rich in phytic acid (inositol hexaphosphate), protein, sugar, inorganic salts, and other components. Phytic acid is the core precursor for the production of inositol (a key raw material in the pharmaceutical and food industries), but traditional processes have the following drawbacks: (1) Resource waste: Phytic acid in corn soaking water is not efficiently extracted and utilized, and is discharged with wastewater; (2) Environmental pressure: Soaking water with high organic matter and high phosphorus content is directly discharged, polluting water bodies and soil; (3) Poor economic efficiency: Existing inositol production mostly uses rice bran and other raw materials, which is costly, complex, and by-products (such as ammonium salts) are not recovered, resulting in low resource utilization. Therefore, it is urgent to develop a process that achieves "full component recovery and full process cleaning" from corn soaking water, realizing the conversion of phytic acid to inositol, recovery of ammonium chloride, and resource utilization of wastewater, thus breaking through the bottleneck of traditional processes. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water as raw material, in order to address the shortcomings of the prior art. This process can obtain high-yield, high-purity and high-yield inositol and magnesium ammonium phosphate products, while also realizing the recovery of ammonium chloride.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water as raw material, the process comprising the following steps:

[0006] (1) The supernatant after corn soaking water is allowed to settle and enters the resin column. After feeding, ammonium chloride solution is used for analysis, and the collected analysis liquid is used for later use.

[0007] (2) Take the eluent from step (1), process it through a nanofiltration membrane, and collect the concentrated solution for later use;

[0008] (3) Take the concentrated solution described in step (2), add hydrolytic enzyme and control the pH and reaction temperature. After the reaction is completed, filter and collect the enzymatic hydrolysate for later use.

[0009] (4) Take the enzymatic hydrolysate from step (3) and concentrate it under vacuum for later use;

[0010] (5) Take the concentrated solution described in step (4) and enter the chromatographic separation system for separation. Use deionized water as the mobile phase for elution and collect the inositol phase and salt phase for later use.

[0011] (6) Take the inositol phase described in step (5), cool and crystallize it, add ethanol to the collected crystals, stir at a temperature not lower than 50°C, filter and collect the crystals, and dry them to obtain an inositol product with a purity of not less than 99.5%.

[0012] (7) Take the salt phase described in step (5), add magnesium chloride, and adjust the pH to alkaline by passing ammonia water through while stirring. After the reaction is completed, filter the residue and dry it to obtain magnesium ammonium phosphate product. The collected filtrate is used for future reference.

[0013] (8) Take the filtrate from step (7), adjust the pH to acidic, concentrate it under vacuum, centrifuge and dry it to obtain the ammonium chloride product.

[0014] As an improved technical solution, the supernatant in step (1) enters the resin column at a flow rate of 0.5-2 BV / h, and the packing material in the resin column is anion exchange resin, specifically model D315, ZGA451 or D301.

[0015] As an improved technical solution, the concentration of the ammonium chloride solution in step (1) is 10-15 wt%, and the ammonium chloride solution enters the resin column at a flow rate of 0.5-1 BV / h.

[0016] As an improved technical solution, the nanofiltration membrane in step (2) has a molecular weight cutoff of 300-500 Da and the solid content of the concentrate is 20-25 wt%.

[0017] As an improved technical solution, the amount of hydrolytic enzyme added in step (2) is 0.5-3% of the solid content of the concentrate. The hydrolytic enzyme includes phytase and protease. The phytase and protease are mixed in a mass ratio of 1:0.5-1, the pH is controlled at 7.0-8.5, and the reaction temperature is 40-60℃.

[0018] As an improved technical solution, the solid content of the concentrate in step (5) is 40-45 wt%, the concentrate enters the chromatographic separation system at a flow rate of 0.5-1 BV / h, the deionized water enters the chromatographic separation system at a flow rate of 0.5-1 BV / h, and the packing material of the chromatographic column in the chromatographic separation system is cation exchange resin, specifically model D001, D031 or D072.

[0019] As an improved technical solution, in step (6), the inositol phase is cooled to 20-25℃ for crystallization and filtration. The collected crystals are added to ethanol and stirred at 50-60℃. The filtered and collected crystals are dried to obtain the inositol product.

[0020] As an improved technical solution, in step (7), after adding magnesium chloride, the molar ratio of phosphate and magnesium ions is controlled to be 1:1, and after passing ammonia water, the pH is adjusted to 8.5-9.

[0021] As an improved technical solution, hydrochloric acid is added in step (8) to adjust the pH to 5-6.

[0022] After adopting the above technical solution, the beneficial effects of the present invention are:

[0023] This invention involves adsorbing the supernatant from corn soaking water after settling through a resin column, then using ammonium chloride as the eluent. The collected eluent is concentrated through a nanofiltration membrane, and the resulting retentate is further concentrated under vacuum. The collected concentrate is then enzymatically hydrolyzed by a hydrolytic enzyme, and the filtered enzymatic hydrolysate is concentrated under vacuum. The resulting concentrate is then fed into a chromatographic separation system, eluted with deionized water, and the inositol and salt phases are collected separately. The collected inositol phase is cooled and crystallized, then ethanol is added for secondary crystallization, filtered, and dried to obtain the inositol product. The collected salt phase is added with magnesium chloride, the pH is adjusted to alkaline, stirred, and filtered. The collected filter residue is dried to obtain the magnesium ammonium phosphate product. The collected filtrate is adjusted to acidic pH, concentrated under vacuum, centrifuged, and dried to obtain the ammonium chloride product. This process yields high-yield, high-purity inositol and magnesium ammonium phosphate products, and also achieves the recovery of ammonium chloride. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Example 1

[0026] A process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water includes the following steps:

[0027] (1) 250L of supernatant (1.3% phytic acid and 1.5% magnesium ions) after corn soaking water was allowed to settle and was fed into a resin column (4 resin columns connected in series, each with a volume of 1.5L and D315 packing material) at a flow rate of 0.5BV / h. After feeding, 6L of 10wt% ammonium chloride solution (flow rate of 0.5BV / h) was used for analysis, and 5.8L of the analysis solution was collected for later use.

[0028] (2) Take 5.8L of the eluent from step (1) and process it through a nanofiltration membrane with a molecular weight cutoff of 300Da (control the operating pressure of 0.3MPa and the temperature of 30℃) to obtain 2.4L of concentrate (solid content of 20%) for later use.

[0029] (3) Take 2.4L of concentrated solution (solid content is 20%) from step (2), add hydrolytic enzyme (phytase and protease are mixed in a mass ratio of 1:0.5) with a solid content of 0.5% of the concentrated solution, control the pH to 7.0, the reaction temperature to 40℃, filter after 8h of reaction, and collect 2.4L of enzyme hydrolysate for later use;

[0030] (4) Take 2.4L of the enzymatic hydrolysate from step (3), and after vacuum concentration treatment (temperature 50℃, vacuum degree -0.08MPa), obtain 1.5L of concentrated solution with a solid content of 40wt% for later use;

[0031] (5) Take 1.5L of the concentrate (solid content is 40wt%) from step (4) and enter it into the chromatographic separation system (including 4 chromatographic columns, each with a volume of 1.5L and D001 packing material) at a flow rate of 0.5BV / h. It should be noted that the 4 chromatographic columns are connected in series during feeding, and the 4 chromatographic columns are no longer connected in series during elution after feeding) for separation. Use 12L of deionized water as the mobile phase for elution (flow rate is 0.5BV / h), and collect 6L of inositol phase and 6L of salt phase for later use.

[0032] (6) Take 6L of inositol phase from step (5), cool it to 20℃ to crystallize, add 6580g of collected crystals to 95% ethanol at a ratio of 1:5, stir at 50℃, filter and dry the collected crystals to obtain an inositol product with a purity of not less than 99.5%.

[0033] (7) Take 6L of salt phase from step (5), add magnesium chloride (so that the molar ratio of phosphate and magnesium ions is 1:1), stir and pass ammonia water to adjust the pH to 8.5. After reacting for 30 minutes, filter and dry the collected filter residue to obtain magnesium ammonium phosphate product. The collected 4.4L filtrate is used for later use.

[0034] (8) Take 4.4L of filtrate from step (7), adjust the pH to 5 with hydrochloric acid, and after vacuum concentration (70℃, vacuum degree -0.09MPa), centrifuge and dry to obtain ammonium chloride product; the crystallization mother liquor collected by centrifugation can be used as liquid fertilizer.

[0035] Example 2

[0036] A process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water includes the following steps:

[0037] (1) 250L of supernatant (1.3% phytic acid and 1.5% magnesium ions) after corn soaking water was allowed to settle and was fed into a resin column (4 resin columns connected in series, each with a volume of 1.5L and D301 packing material) at a flow rate of 1.2 BV / h. After feeding, 12L of ammonium chloride solution with a concentration of 12.5wt% (flow rate of 0.8 BV / h) was used for analysis, and 11.5L of the analysis solution was collected for later use.

[0038] (2) Take 11.5L of the eluent from step (1) and process it through a nanofiltration membrane with a molecular weight cutoff of 400 Da (control the operating pressure of 0.5MPa and the temperature of 45℃) to obtain 4L of concentrate (solid content of 23.2%) for later use.

[0039] (3) Take 4L of concentrated solution (solid content is 23.2%) from step (2), add hydrolytic enzyme (phytase and protease are mixed in a mass ratio of 1:0.8) with a solid content of 1.8% of the concentrated solution, control the pH to 7.8, the reaction temperature to 50℃, filter after 4h of reaction, and collect 4L of enzyme hydrolysate for later use.

[0040] (4) Take 4L of the enzymatic hydrolysate from step (3), and after vacuum concentration treatment (temperature 55℃, vacuum degree -0.085MPa), obtain 2.3L of concentrated solution with a solid content of 42.8wt% for later use;

[0041] (5) Take 2.3L of concentrated solution (solid content is 42.8wt%) from step (4) and enter it into the chromatographic separation system (including 4 chromatographic columns, each with a volume of 0.15L and D031 packing material) at a flow rate of 0.8BV / h. It should be noted that the 4 chromatographic columns are connected in series during feeding, and the 4 chromatographic columns are no longer connected in series during elution after feeding) for separation. Use 24L of deionized water as the mobile phase for elution (flow rate is 0.8BV / h), and collect 12L of inositol phase and 12L of salt phase for later use.

[0042] (6) Take 12L of inositol phase from step (5), cool it to 23℃ to crystallize, add 6520g of collected crystals to 95% ethanol at a ratio of 1:5, stir at 55℃, filter and dry the collected crystals to obtain an inositol product with a purity of not less than 99.5%.

[0043] (7) Take 12L of salt phase from step (5), add magnesium chloride (so that the molar ratio of phosphate and magnesium ions is 1:1), stir and pass ammonia water to adjust the pH to 8.8. After reacting for 45 minutes, filter and dry the collected filter residue to obtain magnesium ammonium phosphate product. The collected 7.8L of filtrate is used for later use.

[0044] (8) Take 7.8L of filtrate from step (7), adjust the pH to 5.5 with hydrochloric acid, concentrate it under vacuum (75℃, vacuum degree -0.095MPa), centrifuge and dry it to obtain ammonium chloride product; the crystallization mother liquor collected by centrifugation can be used as liquid fertilizer.

[0045] Example 3

[0046] A process for preparing inositol and magnesium ammonium phosphate and recovering ammonium chloride from corn soaking water includes the following steps:

[0047] (1) 250L of supernatant (1.3% phytic acid and 1.5% magnesium ions) after corn soaking water has settled and settled was fed into a resin column (4 resin columns connected in series, each resin column has a volume of 1.5L and each resin column is filled with ZGA451) at a flow rate of 2BV / h. After feeding, 8L of ammonium chloride solution with a concentration of 15wt% (flow rate of 1BV / h) was used for analysis and the collected 8L of analysis solution was used for later use.

[0048] (2) Take 8L of the eluent from step (1) and process it through a nanofiltration membrane with a molecular weight cutoff of 500 Da (control the operating pressure of 0.85 MPa and the temperature of 60℃) to obtain 2.2L of concentrate (solid content of 25%) for later use.

[0049] (3) Take 2.2L of concentrated solution (solid content is 25%) from step (2), add hydrolytic enzyme (phytase and protease are mixed in a mass ratio of 1:1) with a solid content of 3% of concentrated solution, control the pH to 8.5, the reaction temperature to 60℃, filter after 6h of reaction, and collect 2.2L of enzyme hydrolysate for later use.

[0050] (4) Take 2.2L of the enzymatic hydrolysate from step (3), and after vacuum concentration treatment (temperature 60℃, vacuum degree -0.09MPa), obtain 1.44L of concentrated solution with a solid content of 45wt% for later use;

[0051] (5) Take 1.44L of concentrated solution (solid content is 45wt%) from step (4) and enter it into the chromatographic separation system (including 4 chromatographic columns, each with a volume of 0.5L and D072 packing material for each column) at a flow rate of 1BV / h. It should be noted that the 4 chromatographic columns are connected in series during feeding, and the 4 chromatographic columns are no longer connected in series during elution after feeding) for separation. Use 24L of deionized water as the mobile phase for elution (flow rate is 1BV / h), and collect 12L of inositol phase and 12L of salt phase for later use.

[0052] (6) Take 12L of inositol phase from step (5), cool it to 25℃ to crystallize, add 6515g of collected crystals to 95% ethanol at a ratio of 1:5, stir at 60℃, filter and dry the collected crystals to obtain an inositol product with a purity of not less than 99.5%.

[0053] (7) Take 12L of salt phase from step (5), add magnesium chloride (so that the molar ratio of phosphate and magnesium ions is 1:1), stir and pass ammonia water to adjust the pH to 9. After reacting for 60 minutes, filter and dry the collected filter residue to obtain magnesium ammonium phosphate product. The collected 8.5L filtrate is used for later use.

[0054] (8) Take 8.5L of filtrate from step (7), adjust the pH to 6 with hydrochloric acid, and after vacuum concentration (80℃, vacuum degree -0.1MPa), centrifuge and dry to obtain ammonium chloride product; the crystallization mother liquor collected by centrifugation can be used as liquid fertilizer.

[0055] To better obtain high-yield, high-purity inositol and magnesium ammonium phosphate products through the process method of this invention, and to achieve effective recovery of ammonium chloride, the following comparative examples are given with reference to Example 2. Specific results are detailed in Table 1.

[0056] Comparative Example 1

[0057] Unlike Example 2, in step (3), the concentrate is introduced into a high-pressure reactor and reacted at 160-180℃ and 0.8MPa for 12 hours to obtain hydrolysate; the rest of the operation is the same.

[0058] Comparative Example 2

[0059] Unlike Example 2, the hydrolase in step (3) contains a protease, but the rest of the operation is the same.

[0060] Comparative Example 3

[0061] Unlike Example 2, in step (3), the pH is controlled at 9, while the rest of the operation is the same.

[0062] Comparative Example 4

[0063] Unlike Example 2, in step (3), the pH is controlled at 6.5, while the rest of the operation is the same.

[0064] Comparative Example 5

[0065] Unlike Example 2, the reaction temperature in step (3) is controlled at 35°C, while the rest of the operation is the same.

[0066] Comparative Example 6

[0067] Unlike Example 2, the reaction temperature in step (3) is controlled at 65°C, while the rest of the operation is the same.

[0068] Comparative Example 7

[0069] Unlike Example 2, in step (7), the pH is adjusted to 8, while the rest of the operation is the same.

[0070] Comparative Example 8

[0071] Unlike Example 2, in step (7), the pH is adjusted to 9.5, while the rest of the operation is the same.

[0072] Comparative Example 9

[0073] Unlike Example 2, in step (8), the pH is adjusted to 4.5, while the rest of the operation is the same.

[0074] Comparative Example 10

[0075] Unlike Example 2, in step (8), the pH is adjusted to 6.5, while the rest of the operation is the same.

[0076] Comparative Example 11

[0077] Unlike Example 2, the filler in the resin column in step (1) is ZGC151, and the rest of the operation is the same.

[0078] Comparative Example 12

[0079] Unlike Example 2, the packing material in the chromatographic column in step (5) is D51, while the rest of the operation is the same.

[0080]

[0081] The data in Table 1 show that the inositol and magnesium ammonium phosphate data in Example 2 are superior to those in other examples and comparative examples.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material, characterized in that, The process comprises the following steps: (1) The supernatant after the corn soaking water is allowed to stand and settle is introduced into a resin column, and after the feeding is completed, ammonium chloride solution is used for elution, and the collected eluate is reserved; (2) The eluate in step (1) is treated by a nanofiltration membrane, and the collected concentrated solution is reserved; (3) The concentrated solution in step (2) is added with a hydrolytic enzyme, and the pH and reaction temperature are controlled, after the reaction is completed, filtration is performed, and the collected enzymatic hydrolysate is reserved; (4) The enzymatic hydrolysate in step (3) is treated by vacuum concentration to obtain a concentrated solution which is reserved; (5) The concentrated solution in step (4) is introduced into a chromatographic separation system for separation, deionized water is used as a mobile phase for elution, and an inositol phase and a salt phase are collected respectively and reserved; (6) The inositol phase in step (5) is cooled and crystallized, the collected crystals are added with ethanol, stirring is performed under the condition that the temperature is not lower than 50 DEG C, the collected crystals are filtered and dried, and an inositol product with a purity of not less than 99.5% is obtained; (7) The salt phase in step (5) is added with magnesium chloride, ammonia water is introduced under stirring to adjust the pH to alkaline, after the reaction is completed, filtration is performed, the collected filter residue is dried to obtain a magnesium ammonium phosphate product, and the collected filtrate is reserved; (8) The filtrate in step (7) is adjusted to be acidic, treated by vacuum concentration, centrifuged and dried, and an ammonium chloride product is obtained.

2. The process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material according to claim 1, characterized in that, In step (1), the supernatant is introduced into the resin column at a flow rate of 0.5-2 BV / h, and the filler in the resin column is D315, ZGA451 or D301.

3. The process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material according to claim 1, characterized in that, In step (1), the concentration of the ammonium chloride solution is 10-15 wt%, and the ammonium chloride solution is introduced into the resin column at a flow rate of 0.5-1 BV / h.

4. The process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material according to claim 1, characterized in that, In step (2), the molecular weight cut-off of the nanofiltration membrane is 300-500 Da, and the solid content of the concentrated solution is 20-25 wt%.

5. The process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material according to claim 1, characterized in that, In step (2), the addition amount of the hydrolytic enzyme is 0.5-3% of the solid content of the concentrated solution, the hydrolytic enzyme comprises phytase and protease, the phytase and the protease are mixed at a mass ratio of 1:0.5-1, the pH is controlled to be 7.0-8.5, and the reaction temperature is controlled to be 40-60 DEG C.

6. The process for preparing inositol, magnesium-ammonium phosphate and recovering ammonium chloride using corn steep liquor as raw material according to claim 1, characterized in that, In step (5), the solid content of the concentrated solution is 40-45 wt%, the concentrated solution is introduced into the chromatographic separation system at a flow rate of 0.5-1 BV / h, deionized water is introduced into the chromatographic separation system at a flow rate of 0.5-1 BV / h, and the filler of the chromatographic column in the chromatographic separation system is D001, D031 or D072.

7. The process of claim 1, wherein the process is characterized by, In step (6), the inositol phase is cooled to 20-25 DEG C for crystallization and filtration, the collected crystals are added with ethanol, stirring is performed under the condition that the temperature is 50-60 DEG C, the collected crystals are filtered and dried, and an inositol product is obtained.

8. The process of claim 1, wherein the process is characterized by, In step (7), after the addition of magnesium chloride, the molar ratio of phosphate and magnesium ions is controlled to be 1:1, and after the introduction of ammonia water, the pH is adjusted to 8.5-9.

9. The process of claim 1, wherein the process is characterized by, In step (8), hydrochloric acid is added to adjust the pH to 5-6.

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