A chromatographic fractionation process for the production of inositol

Abstract

The present application relates to the technical field of inositol, and particularly relates to a chromatographic fractional purification process for inositol production, and specifically comprises the following contents: after hydrolysis and concentration, the feed liquid is treated by using a first chromatographic separation system, the running temperature and valve switching time are controlled, the feed flow rate and feed amount are controlled, the purified water flow rate and water amount are controlled, the low-salt inositol feed liquid collected after treatment is treated by using a second chromatographic separation system, the running temperature and valve switching time are controlled, the feed flow rate and feed amount are controlled, the purified water flow rate and water amount are controlled, and the desalted inositol feed liquid collected after treatment is concentrated, cooled, crystallized, filtered and dried to obtain the inositol product. The above-mentioned purification process greatly improves the purity of inositol, the separation efficiency is improved by using the second chromatographic separation system, and the water consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of inositol, in particular to a chromatographic fractionation and purification process for inositol production. Background Art

[0002] Inositol (inositol), chemically known as cyclohexanehexol, is an important vitamin required by higher animals. The current production process for inositol involves soaking corn in water, passing it through a resin for phytic acid adsorption, followed by desorption, hydrolysis, filtration, separation, and crystallization. Desalination is a key step in the industrial production of inositol, helping to remove metal salts from the inositol solution and improve product purity. Existing processes introduce the inositol solution to be treated into a primary desalination chromatography system, which typically comprises a pretreatment unit, a desalination unit, and a recirculation unit. In the pretreatment unit, the inositol solution undergoes a series of treatment steps before entering the desalination unit. This unit is the core of the desalination process and typically utilizes ion exchange separation technology to remove some of the metal salts and other soluble impurities in the inositol solution. During the desalination process, the inositol solution is continuously circulated through the desalination unit until the desired desalination effect is achieved. It is important to note that the specific continuous recirculation desalination process consumes a large amount of water and requires acid and alkali solutions to regenerate the resin, which inevitably generates a large amount of wastewater. Therefore, in view of the above technical problems, it is necessary to develop a chromatographic fractionation purification process for inositol production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: in view of the deficiencies of the existing technology, a chromatographic fractionation purification process for inositol production is provided, which reduces water consumption while ensuring the quality of inositol.

[0004] In order to solve the above technical problems, the technical solution of the present invention is:

[0005] A chromatographic fractionation purification process for inositol production comprises the following steps:

[0006] (1) the feed liquid after hydrolysis and concentration is first introduced into a primary chromatography separation system, the operating temperature, feed flow rate, feed amount, water inlet speed and water inlet are controlled, and the low-salinity inositol solution is collected for standby use; wherein the primary chromatography separation system comprises four chromatographic columns, the four chromatographic columns are sequentially connected end to end to form a closed loop, the filler of each chromatographic column is Purolite C100, and the diameter-to-height ratio of each chromatographic column is 2:1;

[0007] (2) the low-salt inositol solution in step (1) is introduced into a secondary chromatography separation system, the operating temperature, feed flow rate, feed amount, water inlet speed, and water inlet amount are controlled, and the desalted inositol solution is collected; wherein the secondary chromatography separation system comprises 6 chromatographic columns, the 6 chromatographic columns are sequentially connected end to end to form a closed loop, the filler of each chromatographic column is Lewatit TP 207, and the diameter-to-height ratio of each chromatographic column is 2:1.

[0008] As an improved technical solution, the operating temperature in step (1) is controlled to be 55-65°C.

[0009] As an improved technical solution, in step (1), the feed flow rate is 2-3BV / h, and the feed volume is 0.3-0.4BV of the single column volume; the water inlet rate is 2-3BV / h, and the water inlet volume is 0.3-0.4BV of the single column volume.

[0010] As an improved technical solution, the four chromatographic columns in the primary chromatographic separation system in step (1) are respectively a first chromatographic column, a second chromatographic column, a third chromatographic column and a fourth chromatographic column, the liquid inlet of the first chromatographic column is connected to the liquid delivery pipeline, the material outlet of the first chromatographic column is connected to the material inlet of the second chromatographic column, the material outlet of the second chromatographic column is connected to the material inlet of the third chromatographic column, the material outlet of the third chromatographic column is connected to the material inlet of the fourth chromatographic column, and the material outlet of the fourth chromatographic column is connected to the material inlet of the first chromatographic column.

[0011] As an improved technical solution, the specific operation of separating the feed liquid using a primary chromatography separation system in step (1) is as follows: the feed liquid first enters the first chromatography column and the second chromatography column connected in series, and the salt in the feed liquid flows out from the second chromatography column. When the feed amount is 0.3-0.4BV of the single column volume, the valve is switched, the second chromatography column and the third chromatography column are connected in series, water starts to flow into the first chromatography column, and the low-salt inositol solution flows out from the first chromatography column; the above separation method is cyclically operated in sequence, and the collected low-salt inositol solutions are combined.

[0012] As an improved technical solution, the operating temperature in step (2) is 55-65°C.

[0013] As an improved technical solution, the feed flow rate in step (2) is 2BV / h-4BV / h, and the feed amount is the low-salt inositol solution discharged when water is fed into step (1).

[0014] As an improved technical solution, the six chromatographic columns in the secondary chromatographic separation system in step (2) are respectively chromatographic column No. 1, chromatographic column No. 2, chromatographic column No. 3, chromatographic column No. 4, chromatographic column No. 5 and chromatographic column No. 6, the discharge port of the chromatographic column No. 1 is connected to the chromatographic column No. 2, the discharge port of the chromatographic column No. 2 is connected to the chromatographic column No. 3, the discharge port of the chromatographic column No. 3 is connected to the chromatographic column No. 4, the discharge port of the chromatographic column No. 4 is connected to the chromatographic column No. 5, the discharge port of the chromatographic column No. 5 is connected to the chromatographic column No. 6, and the discharge port of the chromatographic column No. 6 is connected to the chromatographic column No. 1.

[0015] As an improved technical solution, the specific operation of separating the low-salt inositol solution by using a secondary chromatographic separation system in step (2) includes a solution circulation stage, a water-salt circulation stage, and a water-inositol circulation stage; in the solution circulation stage, the low-salt inositol solution enters the chromatographic column No. 1, the chromatographic column No. 2, the chromatographic column No. 3, the chromatographic column No. 4, the chromatographic column No. 5, and the chromatographic column No. 6 in series, and then enters the chromatographic column No. 1 from the chromatographic column No. 6, and after the material circulation is balanced, the valve is switched to enter the water-salt circulation stage; in the water-salt circulation stage, the volume of a single column is 0.3-0. 4BV of purified water enters the serially connected chromatographic columns No. 1, No. 2, No. 3, No. 4 and No. 5 at a flow rate of 2BV / h-3BV / h per column volume, and the salt flows out from the No. 5 column. After the water-salt cycle is completed, the valve is switched to enter the water-inositol cycle stage; in the water-inositol cycle stage, 0.3-0.4BV of purified water per column volume enters the No. 1 column at a flow rate of 2-3BV / h, and the desalted inositol solution flows out from the No. 1 column; the above separation operation is cyclically operated in sequence, and the desalted inositol solutions are combined and collected.

[0016] After adopting the above technical solution, the beneficial effects of the present invention are:

[0017] The present invention processes the hydrolyzed and concentrated feed liquid using a primary chromatography separation system, controls the operating temperature and valve switching time, controls the feed flow rate and feed amount, controls the purified water flow rate and water inflow, and then the low-salt inositol feed liquid collected after the treatment enters a secondary chromatography separation system for treatment, controls the operating temperature and valve switching time, controls the feed flow rate and feed amount, controls the purified water flow rate and water inflow, and then the desalted inositol feed liquid collected after the treatment is concentrated, crystallized by cooling, filtered, and dried to obtain an inositol product. The above-mentioned process method is rationally designed. By screening, it is determined that the filler in four chromatographic columns in the primary chromatography separation system is Purolite C100, and each chromatographic column has a diameter-to-height ratio of 2:1. The filler in six chromatographic columns in the secondary chromatography separation system is Lewatit TP 207, and each chromatographic column has a diameter-to-height ratio of 2:1. This greatly improves the purity of inositol, improves separation efficiency by using the secondary chromatography separation system, and reduces water consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the liquid phase detection spectrum of inositol in Example 2. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] Example 1

[0021] A chromatographic fractionation purification process for inositol production comprises the following steps:

[0022] (1) 3L of feed liquid (0.3BV of a single column volume) that has been hydrolyzed and concentrated to a solid content of 30wt% (the inositol content in the dry matter is 15%, and the other dry matter is potassium dihydrogen phosphate) is first introduced into a primary chromatographic separation system, and the operating temperature is controlled to be 55°C, the feed flow rate is 20L / h, the water inlet rate is 20L / h, and the water inlet volume is 3L. 3L of low-salt inositol solution is collected for standby use; wherein the primary chromatographic separation system includes 4 chromatographic columns (respectively, a first chromatographic column, a second chromatographic column, a third chromatographic column and a fourth chromatographic column, the liquid inlet of the first chromatographic column is connected to a feed liquid delivery pipeline, the material outlet of the first chromatographic column is connected to the material inlet of the second chromatographic column, the material outlet of the second chromatographic column is connected to the material inlet of the third chromatographic column, the material outlet of the third chromatographic column is connected to the material inlet of the fourth chromatographic column, and the material outlet of the fourth chromatographic column is connected to the material inlet of the first chromatographic column. The filler of each chromatographic column is Purolite C100, the ratio of each chromatographic column is 2:1, and the volume of each chromatographic column is 10L);

[0023] The specific separation operation is as follows: the feed liquid first enters the first chromatographic column and the second chromatographic column connected in series, and the salt in the feed liquid flows out from the second chromatographic column. When the feed volume reaches 0.3BV of the single column volume, the valve is switched, the second and third chromatographic columns are connected in series, water begins to flow into the first chromatographic column, and the low-salt inositol solution flows out from the first chromatographic column; the above separation method is circulated in sequence, and the collected low-salt inositol solutions are combined.

[0024] (2) 3 L of the low-salt inositol solution in step (1) is introduced into a secondary chromatography separation system, and the operating temperature is controlled to be 55° C.; wherein the secondary chromatography separation system includes 6 chromatographic columns (respectively, chromatographic column No. 1, chromatographic column No. 2, chromatographic column No. 3, chromatographic column No. 4, chromatographic column No. 5 and chromatographic column No. 6, the discharge port of chromatographic column No. 1 is connected to chromatographic column No. 2, the discharge port of chromatographic column No. 2 is connected to chromatographic column No. 3, the discharge port of chromatographic column No. 3 is connected to chromatographic column No. 4, the discharge port of chromatographic column No. 4 is connected to chromatographic column No. 5, the discharge port of chromatographic column No. 5 is connected to chromatographic column No. 6, and the discharge port of chromatographic column No. 6 is connected to chromatographic column No. 1, the filler of each chromatographic column is Lewatit TP 207, the ratio of each chromatographic column is 2:1, and the volume of each chromatographic column is 10 L).

[0025] The specific separation operation includes a feed-liquid circulation stage, a water-salt circulation stage and a water-inositol circulation stage; in the feed-liquid circulation stage, 3L of the low-salt inositol solution collected in step (1) enters the chromatographic columns No. 1, No. 2, No. 3, No. 4, No. 5 and No. 6 in series at a feed flow rate of 2BV / h, and then enters the chromatographic column No. 1 from the chromatographic column No. 6. After the material circulation is balanced, the valve is switched to enter the water-salt circulation stage; in the water-salt circulation stage, the volume of a single column is 0.3 BV of purified water enters the chromatographic column No. 1, chromatographic column No. 2, chromatographic column No. 3, chromatographic column No. 4 and chromatographic column No. 5 in series at a flow rate of 2BV / h, and the salt flows out from the chromatographic column No. 5. After the water-salt cycle is completed, the valve is switched to enter the water-inositol cycle stage; in the water-inositol cycle stage, 0.3BV of purified water per column enters the chromatographic column No. 1 at a flow rate of 2BV / h, and the desalted inositol solution flows out from the chromatographic column No. 1; the above separation operation is circulated in sequence, and the desalted inositol solution is combined and collected.

[0026] Example 2

[0027] A chromatographic fractionation purification process for inositol production comprises the following steps:

[0028] (1) 3.5 L (0.35 BV of a single column volume) of a feed solution that was hydrolyzed and concentrated to a solid content of 35 wt% (the inositol content in the dry matter was 17%, and the rest was potassium dihydrogen phosphate) was first introduced into a primary chromatography separation system, and the operating temperature was controlled to be 60° C., the feed flow rate was 25 L / h, the water inlet rate was 25 L / h, and the water inlet volume was 3.5 L. 3.5 L of low-salt inositol solution was collected for standby use; wherein the primary chromatography separation system comprises four chromatographic columns (respectively, a first chromatographic column, a second chromatographic column, a third chromatographic column and a fourth chromatographic column, the liquid inlet of the first chromatographic column is connected to a feed liquid delivery pipeline, the material outlet of the first chromatographic column is connected to the material inlet of the second chromatographic column, the material outlet of the second chromatographic column is connected to the material inlet of the third chromatographic column, the material outlet of the third chromatographic column is connected to the material inlet of the fourth chromatographic column, and the material outlet of the fourth chromatographic column is connected to the material inlet of the first chromatographic column, and the filler of each chromatographic column is Purol iteC100, 2:1 for each column, the volume of each column is 10L);

[0029] The specific separation operation is as follows: the feed liquid first enters the first and second chromatographic columns connected in series, and the salt in the feed liquid flows out from the second chromatographic column. When the feed volume reaches 0.25BV of the single column volume, the valve is switched, the second and third chromatographic columns are connected in series, water begins to flow into the first chromatographic column, and the low-salt inositol solution flows out from the first chromatographic column; the above separation method is circulated in sequence, and the collected low-salt inositol solutions are combined.

[0030] (2) taking 3.5L of low-salt inositol solution in step (1) into a secondary chromatography separation system, and controlling the operating temperature to 60°C; wherein the secondary chromatography separation system comprises 6 chromatographic columns (respectively No. 1 chromatographic column, No. 2 chromatographic column, No. 3 chromatographic column, No. 4 chromatographic column, No. 5 chromatographic column and No. 6 chromatographic column, the discharge port of No. 1 chromatographic column is connected to No. 2 chromatographic column, the discharge port of No. 2 chromatographic column is connected to No. 3 chromatographic column, the discharge port of No. 3 chromatographic column is connected to No. 4 chromatographic column, the discharge port of No. 4 chromatographic column is connected to No. 5 chromatographic column, the discharge port of No. 5 chromatographic column is connected to No. 6 chromatographic column, the discharge port of No. 6 chromatographic column is connected to No. 1 chromatographic column, the filler of each chromatographic column is Lewat it TP 207, the ratio of each chromatographic column is 2:1, and the volume of each chromatographic column is 10L).

[0031] The specific separation operation includes a feed-liquid circulation stage, a water-salt circulation stage and a water-inositol circulation stage; in the feed-liquid circulation stage, 3.5 L of the low-salt inositol solution collected in step (1) enters the No. 1 chromatographic column, No. 2 chromatographic column, No. 3 chromatographic column, No. 4 chromatographic column, No. 5 chromatographic column and No. 6 chromatographic column in series at a flow rate of 2.5 BV / h, and then enters the No. 1 chromatographic column from the No. 6 chromatographic column, and after the material circulation is balanced, the valve is switched to enter the water-salt circulation stage; in the water-salt circulation stage, the volume of a single column is 0.35 BV The purified water enters the No. 1 chromatographic column, No. 2 chromatographic column, No. 3 chromatographic column, No. 4 chromatographic column and No. 5 chromatographic columns connected in series at a flow rate of 2.5 BV / h, and the salt flows out from the No. 5 chromatographic column. After the water-salt cycle is completed, the valve is switched to enter the water-inositol cycle stage; in the water-inositol cycle stage, 0.35 BV of purified water per column enters the No. 1 chromatographic column at a flow rate of 2.5 BV / h, and the desalted inositol solution flows out from the No. 1 chromatographic column; the above separation operation is circulated in sequence, and the desalted inositol solution is combined and collected.

[0032] Example 3

[0033] A chromatographic fractionation purification process for inositol production comprises the following steps:

[0034] (1) 4 L (0.4 BV of a single column volume) of a feed solution that was hydrolyzed and concentrated to a solid content of 40 wt% (20% inositol content in the dry matter, the rest being potassium dihydrogen phosphate) was first introduced into a primary chromatography separation system, with the operating temperature controlled at 65° C., the feed flow rate at 30 L / h, the water inlet rate at 30 L / h, and the water inlet volume at 4 L, and 4 L of low-salt inositol solution was collected for standby use; wherein the primary chromatography separation system comprises four chromatographic columns (respectively, a first chromatographic column, a second chromatographic column, a third chromatographic column, and a fourth chromatographic column, the inlet of the first chromatographic column being connected to a feed liquid delivery pipeline, the outlet of the first chromatographic column being connected to the inlet of the second chromatographic column, the outlet of the second chromatographic column being connected to the inlet of the third chromatographic column, the outlet of the third chromatographic column being connected to the inlet of the fourth chromatographic column, and the outlet of the fourth chromatographic column being connected to the inlet of the first chromatographic column, the filler of each chromatographic column being Purolite C100, the ratio of each chromatographic column being 2:1, and the volume of each chromatographic column being 10 L);

[0035] The specific separation operation is as follows: the feed liquid first enters the first chromatographic column and the second chromatographic column connected in series, and the salt in the feed liquid flows out from the second chromatographic column. When the feed volume reaches 4BV of the single injection volume, the valve is switched, the second and third chromatographic columns are connected in series, water begins to flow into the first chromatographic column, and the low-salt inositol solution flows out from the first chromatographic column; the above separation method is circulated in sequence, and the collected low-salt inositol solutions are combined.

[0036] (2) 4 L of low-salt inositol solution in step (1) is introduced into a secondary chromatography separation system, and the operating temperature is controlled to be 65° C.; wherein the secondary chromatography separation system includes 6 chromatographic columns (respectively, chromatographic column No. 1, chromatographic column No. 2, chromatographic column No. 3, chromatographic column No. 4, chromatographic column No. 5 and chromatographic column No. 6, the discharge port of chromatographic column No. 1 is connected to chromatographic column No. 2, the discharge port of chromatographic column No. 2 is connected to chromatographic column No. 3, the discharge port of chromatographic column No. 3 is connected to chromatographic column No. 4, the discharge port of chromatographic column No. 4 is connected to chromatographic column No. 5, the discharge port of chromatographic column No. 5 is connected to chromatographic column No. 6, and the discharge port of chromatographic column No. 6 is connected to chromatographic column No. 1, the filler of each chromatographic column is Lewatit TP 207, the ratio of each chromatographic column is 2:1, and the volume of each chromatographic column is 10 L).

[0037] The specific separation operation includes a feed-liquid circulation stage, a water-salt circulation stage and a water-inositol circulation stage; in the feed-liquid circulation stage, 4L of the low-salt inositol solution in step (1) enters the chromatographic columns No. 1, No. 2, No. 3, No. 4, No. 5 and No. 6 connected in series at a flow rate of 3BV / h, and then enters the chromatographic column No. 1 from the chromatographic column No. 6. After the material circulation is balanced, the valve is switched to enter the water-salt circulation stage; in the water-salt circulation stage, the pure inositol solution with a single column volume of 0.4BV is The purified water enters the serially connected chromatographic columns No. 1, No. 2, No. 3, No. 4 and No. 5 at a flow rate of 3BV / h, and the salt flows out from the No. 5 chromatographic column. After the water-salt cycle is completed, the valve is switched to enter the water-inositol cycle stage; in the water-inositol cycle stage, 0.4BV of purified water per column enters the No. 1 chromatographic column at a flow rate of 3BV / h, and the desalted inositol solution flows out from the No. 1 chromatographic column; the above separation operation is circulated in sequence, and the desalted inositol solution is combined and collected.

[0038] In order to better demonstrate that the process of the present invention can improve the yield and quality of inositol, 12 comparative examples are given with reference to Example 2. The inositol yield, purity and other indicators obtained in Examples 1-3 and Comparative Examples 1-12 are detailed below.

[0039] Comparative Example 1

[0040] The difference from the operation in Example 2 is that the filler in the chromatographic column in the primary chromatographic separation system in step (1) is a polystyrene sulfonic acid type cation exchange resin.

[0041] Comparative Example 2

[0042] The difference from the operation of Example 2 is that the filler in the chromatographic column of the secondary chromatographic separation system in step (2) is DuPont HPR9100 Cl industrial desalting resin.

[0043] Comparative Example 3

[0044] The difference from the operation in Example 2 is that the operating temperature of the primary chromatography separation system in step (1) is 50° C., and the rest of the operations are the same.

[0045] Comparative Example 4

[0046] The difference from the operation in Example 2 is that the operating temperature of the primary chromatography separation system in step (1) is 70° C., and the rest of the operations are the same.

[0047] Comparative Example 5

[0048] The difference from the operation in Example 2 is that the operating temperature of the secondary chromatography separation system in step (1) is 50° C., and the other operations are the same.

[0049] Comparative Example 6

[0050] The difference from the operation in Example 2 is that the operating temperature of the secondary chromatography separation system in step (1) is 70° C., and the other operations are the same.

[0051] Comparative Example 7

[0052] The difference from the operation in Example 2 is that the feed flow rate in step (1) is 3.5 BV / h, and the other operations are the same.

[0053] Comparative Example 8

[0054] The difference from the operation in Example 2 is that the feed flow rate in step (2) is 3.5 BV / h, and the other operations are the same.

[0055] Comparative Example 9

[0056] The difference from the operation in Example 2 is that the water inlet flow rate in step (1) is 3.5 BV / h, and the other operations are the same.

[0057] Comparative Example 10

[0058] The difference from the operation in Example 2 is that in step (2), the purified water in the water-salt circulation stage enters the chromatographic columns 1-5 connected in series at a flow rate of 3.5 BV / h, and the other operations are the same.

[0059] Comparative Example 11

[0060] The operation is different from that in Example 2, in step (2), the purified water in the water-inositol circulation stage enters the No. 1 chromatographic column at a flow rate of 3.5 BV / h, and the other operations are the same.

[0061] Comparative Example 12

[0062] The difference from the operation in Example 2 is that only the primary chromatography separation system in step (1) is used to treat the hydrolyzed liquid, and the remaining operations are the same.

[0063] Table 1

[0064]

[0065]

[0066] The data in Table 1 show that the inositol index, purified water usage, and wastewater volume obtained in Example 2 using the chromatographic fractionation purification process of the present invention are superior to those in Examples 1 and 3. Furthermore, the inositol index, purified water usage, and wastewater volume obtained in Example 2 are superior to those in Comparative Examples 1-12. It should be noted that the water-to-material ratio in Table 1 refers to the amount of purified water required to produce 1 ton of desalted inositol solution using this purification process.

[0067] 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 in the scope of protection of the present invention.

Claims

1. A chromatographic fractionation purification process for inositol production, characterized in that: The following steps are involved: (1) The hydrolyzed and concentrated feed liquid is first fed into a primary chromatography separation system, and the operating temperature, feed flow rate, feed amount, water inlet speed and water inlet amount are controlled to collect the low-salt inositol solution for standby use; wherein the primary chromatography separation system comprises four chromatographic columns, and the four chromatographic columns are sequentially connected end to end to form a closed loop, and the filler of each chromatographic column is Purolite C100, and the diameter-to-height ratio of each chromatographic column is 2:1; (2) taking the low-salt inositol solution described in step (1) into a secondary chromatography separation system, controlling the operating temperature, feed flow rate, feed amount, water inlet speed and water inlet amount, and collecting the desalted inositol solution; The secondary chromatographic separation system comprises six chromatographic columns, namely, chromatographic column 1, chromatographic column 2, chromatographic column 3, chromatographic column 4, chromatographic column 5 and chromatographic column 6, wherein the six chromatographic columns are connected end to end to form a closed loop, the filler of each chromatographic column is Lewatit TP 207, and the diameter-to-height ratio of each chromatographic column is 2:1; The specific operation of separating the low-salt inositol feed liquid by using the secondary chromatography separation system includes a feed liquid circulation stage, a water-salt circulation stage and a water-inositol circulation stage; in the feed liquid circulation stage, the low-salt inositol solution enters the No. 1 chromatographic column, the No. 2 chromatographic column, the No. 3 chromatographic column, the No. 4 chromatographic column, the No. 5 chromatographic column and the No. 6 chromatographic column in series, and then enters the No. 1 chromatographic column from the No. 6 chromatographic column, and after the material circulation is balanced, the valve is switched to enter the water-salt circulation stage; in the water-salt circulation stage, the purified water with a single column volume of 0.3-0.4BV is adjusted according to the flow rate. The flow rate of a single column volume of 2BV / h-3BV / h enters the chromatographic column No. 1, chromatographic column No. 2, chromatographic column No. 3, chromatographic column No. 4 and chromatographic column No. 5 connected in series, and the salt flows out from the chromatographic column No.

5. After the water-salt cycle is completed, the valve is switched to enter the water-inositol cycle stage; in the water-inositol cycle stage, the purified water with a single column volume of 0.3-0.4BV enters the chromatographic column No. 1 at a flow rate of 2-3BV / h, and the desalted inositol solution flows out from the chromatographic column No. 1; the separation operation is cyclically performed in sequence, and the desalted inositol solutions are combined and collected.

2. The chromatographic fractionation purification process for producing inositol according to claim 1, wherein: In step (1), the operating temperature is controlled to be 55-65°C.

3. The chromatographic fractionation purification process for producing inositol according to claim 1, wherein: In step (1), the feed flow rate is 2-3 BV / h, and the feed volume is 0.3-0.4 BV of the volume of a single column; the water inlet rate is 2-3 BV / h, and the water inlet volume is 0.3-0.4 BV of the volume of a single column.

4. The chromatographic fractionation purification process for producing inositol according to claim 1, wherein: The four chromatographic columns in the primary chromatographic separation system in step (1) are respectively a first chromatographic column, a second chromatographic column, a third chromatographic column and a fourth chromatographic column, the liquid inlet of the first chromatographic column is connected to the feed liquid delivery pipeline, the material outlet of the first chromatographic column is connected to the material inlet of the second chromatographic column, the material outlet of the second chromatographic column is connected to the material inlet of the third chromatographic column, the material outlet of the third chromatographic column is connected to the material inlet of the fourth chromatographic column, and the material outlet of the fourth chromatographic column is connected to the material inlet of the first chromatographic column.

5. The chromatographic fractionation purification process for producing inositol according to claim 4, wherein: The specific operation of separating the feed liquid by using the primary chromatography separation system in step (1) is as follows: the feed liquid first enters the first chromatography column and the second chromatography column connected in series, and the salt in the feed liquid flows out from the second chromatography column. When the feed amount is 0.3-0.4BV of the single column volume, the valve is switched, the second chromatography column and the third chromatography column are connected in series, water starts to flow into the first chromatography column, and the low-salt inositol solution flows out from the first chromatography column. The above separation method is circulated in sequence, and the collected low-salt inositol solutions are combined.

6. The chromatographic fractionation purification process for inositol production according to claim 1, wherein: The operating temperature in step (2) is 55-65°C.

7. The chromatographic fractionation purification process for inositol production according to claim 1, wherein: The feed flow rate in step (2) is 2BV / h-4BV / h, and the feed amount is the low-salt inositol solution discharged during the water inlet in step (1).

8. The chromatographic fractionation purification process for inositol production according to claim 1, wherein: In the secondary chromatographic separation system in step (2), the discharge port of the chromatographic column No. 1 is connected to the chromatographic column No. 2, the discharge port of the chromatographic column No. 2 is connected to the chromatographic column No. 3, the discharge port of the chromatographic column No. 3 is connected to the chromatographic column No. 4, the discharge port of the chromatographic column No. 4 is connected to the chromatographic column No. 5, the discharge port of the chromatographic column No. 5 is connected to the chromatographic column No. 6, and the discharge port of the chromatographic column No. 6 is connected to the chromatographic column No. 1.

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