A process for the preparation of dl-magnesium lactate and phytate desorbent using corn steep liquor

Abstract

The present application relates to the technical field of corn soaking water recovery processing, and particularly relates to a process method for preparing DL-magnesium lactate and phytate desorbent by using corn soaking water, which comprises the following steps: (1) taking supernatant of corn soaking water after standing and countercurrently feeding into a cation resin column, collecting first effluent and feeding into a first anion resin column, and collecting second effluent and feeding into a second anion resin column; (2) taking hydrochloric acid and feeding into the cation resin column in a normal flow mode, and collecting desorption solution with pH 2.5-3; (3) taking the desorption solution with pH 2.5-3, and collecting potassium chloride filter cake after concentration, crystallization and separation; collecting filtrate, and collecting magnesium chloride filter cake after concentration, crystallization and separation; (4) configuring the potassium chloride filter cake into a solution as phytate desorbent; and (5) taking the magnesium chloride filter cake, and configuring into a solution as lactate desorbent. By using the process method, potassium ions and magnesium ions in the corn soaking water can be recovered, and phytate desorbent and DL-magnesium lactate products are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of corn soaking water recovery processing, in particular to a process method for preparing DL-magnesium lactate and phytate desorbent from corn soaking water. BACKGROUND

[0002] In the production process of corn starch wet milling method, corn soaking water is the main production wastewater, and the solid content is about 10-12%, mainly containing 5-6% protein, 2-3% lactic acid, 1% phytic acid, 1% sugar, 0.5% potassium ion and 0.1% magnesium ion and a small amount of starch residue and other substances. At present, most of the treatment processes for these components in corn soaking water are to recover phytic acid. Because the acidity of lactic acid is lower than that of phytic acid, the content of magnesium element and potassium element is low, the cost of the product obtained by direct separation does not have economic value, but if the lactic acid and potassium ion are directly discarded as waste, it will cause resource waste. In the existing technology, the commercially available potassium chloride is configured into a desorbent of a certain concentration when desorbing phytic acid. If the potassium ion in corn soaking water is recovered as a phytic acid desorbent, the cost of the enterprise will undoubtedly be reduced. Therefore, in view of the above problems, a process method for preparing DL-magnesium lactate and phytate desorbent from corn soaking water is explored and researched. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a process method for preparing DL-magnesium lactate and phytate desorbent from corn soaking water in view of the deficiencies in the prior art. The process method realizes the recovery of potassium ions, thereby obtaining a desorbent for desorbing phytic acid, saving costs, and also obtaining DL-magnesium lactate product.

[0004] To solve the above technical problems, the technical scheme of the present application is:

[0005] A process method for preparing DL-magnesium lactate and phytate desorbent from corn soaking water, the process method comprising the following steps:

[0006] (1) The supernatant after standing of corn soaking water is countercurrently introduced into a cation resin column, the first effluent collected is countercurrently introduced into a first anion resin column, the second effluent collected is countercurrently introduced into a second anion resin column, and the third effluent collected is reserved;

[0007] (2) Hydrochloric acid is introduced into the cation resin column in step (1) in a forward flow, and the desorption solution with pH 2.5-3 is reserved; the desorption solution with pH less than 2.5 is collected and used as the preparation of the next batch of hydrochloric acid;

[0008] (3) Collecting the potassium chloride filter cake obtained after concentration, crystallization, separation of the desorption solution with pH 2.5-3 in step (2) for standby; continuing to concentrate, crystallize and separate the collected filtrate, and collecting the magnesium chloride filter cake for standby;

[0009] (4) Taking the potassium chloride filter cake in step (3), configuring a 10wt%-12wt% potassium chloride solution as a phytate desorbent, and flowing into the first anion resin column, and collecting the potassium phytate effluent for standby;

[0010] (5) Taking the magnesium chloride filter cake in step (3), configuring an 8wt%-12wt% magnesium chloride solution as a desorbent, and flowing into the second anion resin column, and concentrating, decolorizing, crystallizing, filtering, washing with water and drying the effluent to obtain a DL-magnesium lactate product.

[0011] As an improved technical solution, the resin filled in the cation resin column in step (1) is CH-10; the resin filled in the first anion resin column is macroporous adsorption resin D312; and the resin filled in the second anion resin column is Zhengguang J18.

[0012] As an improved technical solution, the supernatant in step (1) flows into the cation resin at a flow rate of 0.5-0.6 BV / h; the first effluent flows into the first anion resin column at a flow rate of 1-1.25 BV / h; and the second effluent flows into the second anion resin at a flow rate of 1-1.25 BV / h.

[0013] As an improved technical solution, the concentration of the hydrochloric acid in step (2) is 15%-23% w / w.

[0014] As an improved technical solution, the desorption solution in step (3) is concentrated to a solid content of 70-80wt% before crystallization.

[0015] As an improved technical solution, the filtrate in step (3) is concentrated to a solid content of 70-85wt% before crystallization.

[0016] As an improved technical solution, the magnesium chloride solution in step (5) flows into the second anion resin column at a flow rate of 0.3-0.5 BV / h.

[0017] As an improved technical solution, before the magnesium chloride solution in step (5) flows into the second anion resin column, the second anion resin column is first washed with purified water until the effluent is colorless, and then washed with the magnesium chloride solution.

[0018] After the above technical solution is adopted, the beneficial effects of the present application are:

[0019] The present application first passes the supernatant after the settlement of corn soaking water through a cation resin column, which can adsorb potassium ions and metal ions such as calcium and magnesium, then passes the first effluent through a first anion resin column to adsorb phytic acid, then passes the second effluent through a second anion resin column to adsorb lactic acid, then uses hydrochloric acid to desorb the potassium ions and calcium and magnesium ions adsorbed on the cation resin column, collects the effluent of 2.5-3 to concentrate, crystallize, and separate, collects the potassium chloride filter cake to prepare a phytic acid desorbent, continues to concentrate, crystallize, and separate the filtrate, collects the magnesium chloride filter cake to prepare a lactic acid desorbent, and then passes the effluent through concentration, decolorization, crystallization, separation, and drying to obtain a DL-magnesium lactate product. The above process can recover potassium ions and magnesium ions in corn soaking water, which are used as phytic acid desorbents and lactic acid desorbents, respectively, which on the one hand reduces the demand for commercially available potassium chloride during phytic acid desorption, thereby reducing the cost of the phytic acid desorbent, and on the other hand avoids the waste of potassium and magnesium ions in corn soaking water, obtains a DL-magnesium lactate byproduct, and further increases the economic benefits of enterprises. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application is further described in detail in conjunction with the following examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0021] Example 1

[0022] A process for preparing DL-magnesium lactate and a phytic acid desorbent from corn soaking water, comprising the following steps:

[0023] (1) 1000 ml of supernatant after the standing of corn soaking water is passed into a cation resin column (the filled resin is CH-10) at a flow rate of 0.5 BV / h in countercurrent, the collected first effluent is passed into a first anion resin column (the filled resin is macroporous adsorption resin D312) at a flow rate of 1 BV / h in countercurrent, the collected second effluent is passed into a second anion resin column (the filled resin is Zhengguang J18) at a flow rate of 1 BV / h in countercurrent, and the collected third effluent is reserved (for entering a corn water-soluble protein recovery process);

[0024] (2) 15% w / w hydrochloric acid is passed into the cation resin column in step (1) at a flow rate of 0.1 BV / h in cocurrent, and the desorption liquid with pH 2.5-3 is reserved; the desorption liquid with pH less than 2.5 is collected and used as the preparation of the next batch of hydrochloric acid;

[0025] (3) Take the desorption solution of pH 2.5-3 in step (2), concentrate to solid content of 70wt% at 70°C under vacuum 0.07-0.09Mpa, then cool to 25°C to crystallize, centrifuge and filter to separate, and collect the obtained potassium chloride filter cake for standby; collect the filtrate, concentrate to solid content of 70wt% at 70°C under vacuum 0.07-0.09Mpa, then cool to 25°C to crystallize, centrifuge and filter to separate, and collect the obtained magnesium chloride filter cake for standby;

[0026] (4) Take the potassium chloride filter cake in step (3), configure a 10wt% potassium chloride solution as a phytate desorbent, and let it flow into the first anion resin column to collect the potassium phytate effluent for standby (enter the inositol production process);

[0027] (5) Take the magnesium chloride filter cake in step (3), configure an 8wt% magnesium chloride solution as a desorbent, and let it flow into the second anion resin column at a flow rate of 0.3BV / h, concentrate the collected effluent to solid content of 50wt%, add 1% activated carbon by weight of solid to decolorize, filter out the waste carbon, and then stir the filtrate to evaporate water at 50-70°C under vacuum 0.07-0.09Mpa, stop concentrating when the refractive solid content is 70wt% by sampling, cool to crystallize, filter, wash with water, and dry to obtain the DL-magnesium lactate product. Before the magnesium chloride solution flows into the second anion resin column, first flush the second anion resin column with purified water until the effluent is colorless, and then flush it with the magnesium chloride solution.

[0028] Example 2

[0029] A process for preparing DL-magnesium lactate and a phytate desorbent from corn soaking water, comprising the following steps:

[0030] (1) Take 1000ml of supernatant after standing of corn soaking water, and let it flow countercurrently into a cation resin column (filled with CH-10 resin) at a flow rate of 0.53BV / h, collect the first effluent, let it flow countercurrently into a first anion resin column (filled with macroporous adsorption resin D312) at a flow rate of 1.1BV / h, collect the second effluent, let it flow countercurrently into a second anion resin column (filled with Zhengguang J18) at a flow rate of 1.1BV / h, and collect the third effluent for standby (enter the corn water-soluble protein recovery process);

[0031] (2) Take 18%w / w hydrochloric acid, and let it flow into the cation resin column in step (1) at a flow rate of 0.15BV / h to collect the desorption solution at pH 2.5-3 for standby; collect the desorption solution at pH less than 2.5 for the preparation of the next batch of hydrochloric acid;

[0032] (3) Take the desorption solution of pH 2.5-3 in step (2), concentrate to solid content of 70wt% under vacuum 0.07-0.09Mpa, then cool to 25℃ to crystallize, centrifuge and filter to separate, and collect the obtained potassium chloride filter cake for standby; collect the filtrate, concentrate to solid content of 75wt% under vacuum 0.07-0.09Mpa, then cool to 25℃ to crystallize, centrifuge and filter to separate, and collect the obtained magnesium chloride filter cake for standby;

[0033] (4) Take the potassium chloride filter cake in step (3), configure a 11wt% potassium chloride solution as phytate desorbent, and flow into the first anion resin column, collect the potassium phytate effluent for standby (enter the inositol production process);

[0034] (5) Take the magnesium chloride filter cake in step (3), configure a 9wt% magnesium chloride solution as desorbent, and flow into the second anion resin column at a flow rate of 0.35BV / h, concentrate the effluent to solid content of 50wt%, then add 1% activated carbon by weight of solid to decolorize, filter out the waste carbon, and then stir the filtrate to evaporate water under vacuum 0.07-0.09Mpa at 50-70℃, stop concentrating when the refractive solid content is 70wt% by sampling, cool to crystallize, filter, wash with water, and dry to obtain the DL-magnesium lactate product. Before the magnesium chloride solution flows into the second anion resin column, first flush the second anion resin column with purified water until the effluent is colorless, and then flush with the magnesium chloride solution.

[0035] Example 3

[0036] A process for preparing DL-magnesium lactate and phytate desorbent from corn soaking water, comprising the following steps:

[0037] (1) Take 1000ml of supernatant of corn soaking water after standing, and flow countercurrently into a cation resin column (filled with CH-10 resin) at a flow rate of 0.55BV / h, collect the first effluent, flow countercurrently into a first anion resin column (filled with macroporous adsorption resin D312) at a flow rate of 1.15BV / h, collect the second effluent, flow countercurrently into a second anion resin column (filled with Zhengguang J18) at a flow rate of 1.15BV / h, and collect the third effluent for standby (enter the corn water-soluble protein recovery process);

[0038] (2) Take 20%w / w hydrochloric acid, and flow into the cation resin column in step (1) at a flow rate of 0.2BV / h, collect the desorption solution of pH 2.5-3 for standby; collect the desorption solution of pH less than 2.5 for the preparation of the next batch of hydrochloric acid;

[0039] (3) Take the desorption solution of pH 2.5-3 in step (2), concentrate to 75wt% solid content under vacuum 0.07-0.09Mpa, and then cool to 25℃ to crystallize. After centrifugal filtration separation, the collected potassium chloride filter cake is reserved for use; the collected filtrate is concentrated to 75wt% solid content under vacuum 0.07-0.09Mpa, and then cooled to 25℃ to crystallize. After centrifugal filtration separation, the collected magnesium chloride filter cake is reserved for use;

[0040] (4) Take the potassium chloride filter cake in step (3), configure it into a 11wt% potassium chloride solution as a phytate desorbent, and then flow into the first anion resin column. The collected potassium phytate effluent is reserved for use (entering the inositol production process);

[0041] (5) Take the magnesium chloride filter cake in step (3), configure it into a 10wt% magnesium chloride solution as a desorbent, and then flow into the second anion resin column at a flow rate of 0.4BV / h. After the collected effluent is concentrated to 50wt% solid content, 1% activated carbon by weight of the solid is added for decolorization. After filtering out the waste carbon, the filtrate is stirred and heated to 50-70℃ under vacuum 0.07-0.09Mpa to evaporate water. During the process, sample is taken to measure the refractive solid content of 70wt% to stop the concentration. After cooling, crystallization, filtration, water washing and drying, the DL-magnesium lactate product is obtained. Before the magnesium chloride solution flows into the second anion resin column, the second anion resin column is first washed with purified water until the effluent is colorless, and then washed with the magnesium chloride solution.

[0042] Example 4

[0043] A process for preparing DL-magnesium lactate and phytate desorbent from corn soaking water, comprising the following steps:

[0044] (1) Take 1000ml of supernatant after the corn soaking water is left standing, and then flow into the cation resin column (filled with CH-10 resin) countercurrently at a flow rate of 0.58BV / h. The collected first effluent flows into the first anion resin column (filled with macroporous adsorption resin D312) countercurrently at a flow rate of 1.2BV / h. The collected second effluent flows into the second anion resin column (filled with Zhengguang J18) countercurrently at a flow rate of 1.2BV / h. The collected third effluent is reserved for use (entering the corn water-soluble protein recovery process);

[0045] (2) Take 20%w / w hydrochloric acid, and then flow into the cation resin column in step (1) countercurrently at a flow rate of 0.25BV / h. The collected desorption solution with pH 2.5-3 is reserved for use; the desorption solution with pH less than 2.5 is collected and used as the configuration of the next batch of hydrochloric acid;

[0046] (3) Take the desorption solution of pH 2.5-3 in step (2), concentrate to solid content of 78wt% at 70°C under vacuum 0.07-0.09Mpa, then cool to 25°C to crystallize, centrifuge and filter to separate, and collect the obtained potassium chloride filter cake for standby; collect the filtrate, concentrate to solid content of 80wt% at 70°C under vacuum 0.07-0.09Mpa, then cool to 25°C to crystallize, centrifuge and filter to separate, and collect the obtained magnesium chloride filter cake for standby;

[0047] (4) Take the potassium chloride filter cake in step (3), configure it into a 11wt% potassium chloride solution as a phytate desorbent, and flow into the first anion resin column, collect the potassium phytate effluent for standby (enter the inositol production process);

[0048] (5) Take the magnesium chloride filter cake in step (3), configure it into a 11wt% magnesium chloride solution as a desorbent, and flow into the second anion resin column at a flow rate of 0.45BV / h, collect the effluent, concentrate to solid content of 50wt%, add 1% activated carbon by weight of solid to decolorize, filter out the waste carbon, and then stir the filtrate to evaporate water at 50-70°C under vacuum 0.07-0.09Mpa, stop concentrating when the refractive solid content is 70wt% by sampling, cool to crystallize, filter, wash with water, and dry to obtain the DL-magnesium lactate product. Before the magnesium chloride solution flows into the second anion resin column, first flush the second anion resin column with purified water until the effluent is colorless, and then flush it with the magnesium chloride solution.

[0049] Example 5

[0050] A process for preparing DL-magnesium lactate and phytate desorbent from corn soaking water, comprising the following steps:

[0051] (1) Take 1000ml of supernatant after standing of corn soaking water, and flow countercurrently into a cation resin column (filled with CH-10 resin) at a flow rate of 0.6BV / h, collect the first effluent, flow countercurrently into a first anion resin column (filled with macroporous adsorption resin D312) at a flow rate of 1.25BV / h, collect the second effluent, flow countercurrently into a second anion resin column (filled with Zhengguang J18) at a flow rate of 1.25BV / h, and collect the third effluent for standby (enter the corn water-soluble protein recovery process);

[0052] (2) Take 23% w / w hydrochloric acid, and flow into the cation resin column in step (1) at a flow rate of 0.3BV / h, collect the desorption solution of pH 2.5-3 for standby; collect the desorption solution of pH less than 2.5 for the preparation of the next batch of hydrochloric acid;

[0053] (3) the desorption solution with pH 2.5-3 in step (2) is concentrated under vacuum 0.07-0.09 Mpa to solid content of 80 wt% at 70℃, then cooled to 25℃ to crystallize, centrifugal filtration separation, and the collected potassium chloride filter cake is reserved; the collected filtrate is concentrated under vacuum 0.07-0.09 Mpa to solid content of 85 wt% at 70℃, then cooled to 25℃ to crystallize, centrifugal filtration separation, and the collected magnesium chloride filter cake is reserved;

[0054] (4) the potassium chloride filter cake in step (3) is configured into 12 wt% potassium chloride solution as phytate desorbent, and is positively flowed into the first anion resin column, and the collected potassium phytate effluent is reserved (for inositol production process);

[0055] (5) the magnesium chloride filter cake in step (3) is configured into 12 wt% magnesium chloride solution as desorbent, and is positively flowed into the second anion resin column at a flow rate of 0.5 BV / h, and the collected effluent is concentrated to solid content of 50 wt%, 1% activated carbon by weight of solid is added for decolorization, the filtrate after the waste carbon is filtered off is stirred to evaporate water under vacuum 0.07-0.09 Mpa at 50-70℃, and the process is stopped when the refractive solid content is 70 wt% by sampling, and then cooled to crystallize, filtered, washed with water and dried to obtain DL-magnesium lactate product. Before the magnesium chloride solution is positively flowed into the second anion resin column, the second anion resin column is first washed with purified water until the effluent is colorless, and then washed with the magnesium chloride solution.

[0056] In order to better prove that the process method of the application has good technical effect, four comparative examples are given for reference, the yield, yield and purity of DL-magnesium lactate in examples 1-5 and comparative examples 1-3, and the yield, yield and purity of potassium chloride, wherein the yield and yield of DL-magnesium lactate and potassium chloride correspond to 1000 L of supernatant after corn soaking water settlement, and the specific details are shown in Table 1.

[0057] Comparative example 1

[0058] Different from example 4 is that the concentration of the magnesium chloride solution configured in step (5) is 12 wt%, and the rest of the operations are the same.

[0059] Comparative example 2

[0060] Different from example 4 is that the concentration of the magnesium chloride solution configured in step (5) is 8 wt%, and the rest of the operations are the same.

[0061] Comparative example 3

[0062] Different from example 4 is that the resin in the second anion resin column in step (1) is LXD-762, and the rest of the operations are the same.

[0063] Comparative Example 4

[0064] The supernatant after the corn soaking water was settled was passed through an anion resin column, and then a commercially available potassium chloride was configured into an 11wt% potassium chloride solution as a phytic acid desorbent; 1000L of the supernatant after the corn soaking water was settled required 7.5kg of commercially available potassium chloride to desorb phytic acid.

[0065] Table 1

[0066]

[0067] It can be found from the data in Table 1 that, compared with the process methods of Comparative Examples 1-3, the process method of the present application can improve the yield, purity and yield of DL-magnesium lactate and potassium chloride, and the obtained potassium chloride can be used as a phytic acid desorbent, greatly reducing the amount of commercially available potassium chloride.

[0068] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the preparation of DL-magnesium lactate and phytate desorbent from corn steep liquor characterized in that The process includes the following steps: (1) Take the supernatant after the corn soaking water has been left to stand and let it stand. Let it flow back into the cation exchange resin column. Let the first effluent collected flow back into the first anion exchange resin column. Let the second effluent collected flow back into the second anion exchange resin column. Let the third effluent collected be used for later use. The resin filled in the cation exchange resin column is CH-10. The resin filled in the first anion exchange resin column is macroporous adsorption resin D312. The resin filled in the second anion exchange resin column is Zhengguang J18. (2) Take hydrochloric acid and pass it into the cation exchange resin column described in step (1) in the forward flow. Collect the desorption solution with a pH of 2.5-3 for later use. Collect the desorption solution with a pH less than 2.5 for the preparation of the next batch of hydrochloric acid. The concentration of the hydrochloric acid is 15%-23% w / w. (3) Take the desorption solution with pH 2.5-3 from step (2), concentrate, crystallize and separate it to obtain potassium chloride filter cake for later use; continue to concentrate, crystallize and separate the collected filtrate to obtain magnesium chloride filter cake for later use. (4) Take the potassium chloride filter cake from step (3) and prepare a 10wt%-12wt% potassium chloride solution as a phytic acid desorbent and pass it into the first anion exchange resin column. The collected potassium phytate effluent is then used for later use. (5) Take the magnesium chloride filter cake from step (3) and prepare an 8wt%-12wt% magnesium chloride solution as a desorbent and pass it into the second anion exchange resin column. The collected effluent is concentrated, decolorized, crystallized, filtered, washed with water and dried to obtain DL-magnesium lactate product.

2. A process for the preparation of DL-magnesium lactate and phytate desorbent from corn steep liquor as claimed in claim 1, wherein: In step (1), the supernatant is introduced into the cation exchange resin at a flow rate of 0.5-0.6 BV / h; the first effluent is introduced into the first anion exchange resin column at a flow rate of 1-1.25 BV / h; and the second effluent is introduced into the second anion exchange resin at a flow rate of 1-1.25 BV / h.

3. The process for preparing DL-magnesium lactate and phytic acid desorbent using corn soaking water according to claim 1, characterized in that: The desorption solution described in step (3) is concentrated to a solid content of 70-80 wt% and then crystallized.

4. A process for the preparation of DL-magnesium lactate and phytate desorbent from corn steep liquor as claimed in claim 1, wherein: The filtrate in step (3) is concentrated to a solid content of 70-85 wt% and then crystallized.

5. The process for preparation of DL-magnesium lactate and phytate desorbent from corn steep liquor as claimed in claim 1 wherein: The magnesium chloride solution described in step (5) is introduced into the second anion exchange resin column at a flow rate of 0.3-0.5 BV / h.

6. The process for preparing DL-magnesium lactate and phytic acid desorbent using corn soaking water according to claim 1, characterized in that: Before the magnesium chloride solution flows into the second anion exchange resin column in step (5), the second anion exchange resin column is first rinsed with purified water until the effluent is colorless, and then rinsed with the magnesium chloride solution.

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