WO2023109027A1 - Method for desalting and purifying 1,3-propanediol fermentation broth - Google Patents

Abstract

Disclosed is a method for desalting and purifying a 1,3-propanediol fermentation broth. The method comprises: sequentially subjecting a 1,3-propanediol fermentation broth to filtration, sterilization and concentration to obtain a primary concentrated solution; carrying out specific chromatographic separation desalination on the obtained primary concentrated solution by means of using a chromatographic separation system to obtain a desalted solution; concentrating the obtained desalted solution to obtain a secondary concentrated solution, and then purifying the obtained secondary concentrated solution to obtain 1,3-propanediol. By means of the specific chromatographic separation desalination process, the 1,3-propanediol fermentation broth can be directly subjected to chromatographic separation desalination after being subjected to ultrafiltration in the early stage, the nanofiltration membrane filtration procedure is reduced, and the extraction process of 1,3-propanediol is simplified; moreover, the product yield of 1,3-propanediol in the desalination process of the 1,3-propanediol fermentation broth can reach 98% or above, the chromatographic separation desalination rate is increased to 90% or above, the residual amount in a distillation kettle is significantly reduced, the product yield of 1,3-propanediol in a distillation process is improved, and the product quality is significantly improved.

Description

A kind of 1,3-propanediol fermented liquid desalination purification method technical field

The invention relates to the technical field of preparation of bio-based new materials, in particular to a method for desalting and purifying 1,3-propanediol fermentation liquid.

Background technique

1,3-propanediol (1,3-propanediol, 1,3-PDO) is a colorless, odorless, salty, hygroscopic viscous liquid, which is used to produce unsaturated polyester, plasticizer, surfactant , emulsifier and demulsifier raw material; in the polyurethane industry, it is often used as the raw material of polyester polyol, the initiator of polyether polyol and the chain extender of polyurethane, etc.; in the organic chemical industry, it is also important Monomers and intermediates are mainly used as polymer monomers, such as synthesizing polytrimethylene terephthalate (PTT), etc.

In the process of microbial fermentation to produce PDO, while the bacteria metabolize to produce PDO, it also produces by-products 2,3-butanediol (BDO) and organic acids such as succinic acid, acetic acid, and lactic acid. In addition, it is used as a fermentative nitrogen source. After the ammonium ion in the ammonium sulfate is consumed, the pH value of the fermented liquid also reduces, and in order to maintain the pH value of the fermented liquid to be neutral, it is necessary to add lye such as sodium hydroxide aqueous solution in the fermented liquid, so after the fermentation finishes, The fermentation broth will contain a large amount of salt, the salt content can reach about 3%. If the salt is not removed, subsequent rectification and other processes will be difficult to carry out, thereby hindering the extraction of 1,3-propanediol.

At present, there are many methods for desalting PDO fermentation broth, such as ion exchange, nanofiltration desalination, electrodialysis, alcohol precipitation, etc., but these methods still have low separation efficiency, unsuitable for industrialization, and environmental pollution. With the improvement of heterogeneous membrane performance, it gradually replaces the expensive homogeneous membrane, which greatly reduces the investment in electrodialysis equipment and promotes the industrial application of electrodialysis in the field of desalination of 1,3-propanediol fermentation broth ;

However, on the one hand, the PDO fermented liquid produced by the fermentation method, the fermented liquid is usually sterilized by ultrafiltration membrane filtration and protein removed by nanofiltration membrane, and then desalted by electrodialysis. Electrodialysis utilizes the anions and Under the action of an electric field, the cations migrate to the two stages of the electric field and then pass through the anion exchange membrane and the cation exchange membrane, thereby realizing the process of removing anions and cations from the PDO fermentation broth. The salt in the PDO fermentation broth is mainly organic acid The main salts are sodium succinate and sodium acetate, which cannot be completely dissociated in aqueous solution, especially in the late stage of electrodialysis desalination, when the concentration of organic salt is extremely low, the phenomenon of water dissociation is serious, resulting in a decrease in the current efficiency of the fermentation broth , the pH value of the fermentation broth decreases; in addition, the residual protein in the fermentation broth will pollute the ion exchange membrane during the electrodialysis desalination process, resulting in a decrease in the efficiency of electrodialysis desalination;

On the other hand, during the electrodialysis desalination process of PDO fermentation broth, not only anions and cations will pass through the ion exchange membrane, but also products such as PDO and BDO will also diffuse from the light room solution through the exchange membrane to the concentrated room solution due to the concentration difference. According to the company's current production data, the loss rate of PDO, BDO and other products during the desalination process of PDO fermentation broth is about 5%. According to the current price of 30,000 yuan/ton, the value of this part of PDO is as high as 30 million yuan, and the desalination rate of electrodialysis desalination is not ideal. After the desalination solution is subsequently concentrated, the salt concentration is increased. The salt remaining in the material in the subsequent purification process will also affect the product yield of the distillation process, causing a large amount of still residue to be generated in the distillation process. The PDO product remaining in the still residue needs to be further recovered by scraper evaporation process, resulting in a more complicated process. Although Under the premise of not considering the energy consumption, electrodialysis desalination can be repeated many times to improve the desalination rate, but it is obviously not conducive to industrial application.

Contents of the invention

The purpose of the invention is to overcome the deficiencies in the prior art, to provide a kind of improved 1,3-propanediol fermented liquid desalination purification method, this method can have higher PDO product yield, lower still residue and more Fewer process steps.

In order to achieve the above-mentioned purpose, the technical solution adopted in the present invention is: a method for desalting and purifying 1,3-propanediol fermentation liquid, producing 1,3-propanediol by microbial fermentation to obtain 1,3-propanediol fermentation liquid, the purification method Including the following steps:

(1) sterilizing and concentrating the 1,3-propanediol fermentation broth sequentially to obtain a primary concentrate;

(2) Carrying out chromatographic separation and desalination of the primary concentrate obtained in step (1) by using a chromatographic separation system, the chromatographic separation system comprising n sequentially connected chromatographic separation columns, where n is an integer greater than or equal to 3;

The chromatographic separation and desalination includes m continuous repetition periods, m and n are the same; wherein, the following procedures are performed sequentially in each repetition period:

Feed cycle: pass part of the primary concentrated liquid into the chromatographic separation system for circulation until a chromatographic separation column enriches component A, and a chromatographic separation column enriches component B, and the component A contains 1 , 3-propanediol, the component B contains salt;

The first discharge: from the entrance of the chromatographic separation column enriched in component A, the eluent is introduced to push component A out of the chromatographic separation column enriched in component A, and collect;

Part of the primary concentrate is introduced from the inlet of the previous chromatographic separation column of the chromatographic separation column enriched in component B, and component B is pushed out from the chromatographic separation column enriched in component B for collection; the previous chromatographic separation The column is the previous one in the opposite direction of the chromatographic separation column enriched in component B along the circulation flow direction;

The second discharge: the eluent is fed into the inlet of the eluent from the first discharge, and the remaining component B in the chromatographic separation column enriched in component B in the first discharge is pushed out ,collect;

Controlling two adjacent repeating periods, the latter repeating period has the following changes compared to the previous repeating period:

In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction;

In the second discharge, the chromatographic separation columns that collect the remaining component B are all switched to the next one along the circulation flow direction;

After completing m repetition periods, mix the components A collected multiple times to obtain a desalted solution;

(3) Concentrating the desalted solution obtained in step (2) to obtain a secondary concentrate, and then purifying the obtained secondary concentrate to obtain 1,3-propanediol.

In the present invention, the resin in the chromatographic separation column is always in the chromatographic separation column, and the primary concentrated solution and eluent passed through move relative to the resin.

According to some preferred aspects of the present invention, in step (1), ultrafiltration is used for the filter sterilization. According to a specific aspect of the present invention, the ultrafiltration is performed by using a ceramic membrane for bacteria and protein removal, and the filter pore size of the ceramic membrane is 5nm-50nm.

According to some preferred aspects of the present invention, in step (1), the concentration adopts multi-effect evaporation concentration, MVR evaporation concentration or multi-effect rectification, and the water content of the primary concentrate is 50-70wt%. Controlling the amount of water within this range can significantly reduce the amount of eluent added, reduce the cost of subsequent evaporation and dehydration, and improve the economy of the entire process. According to a specific aspect of the present invention, in step (1), the concentration adopts multi-effect evaporation concentration, and the multi-effect evaporation concentration refers to the steam of the previous effect as the heat source of the latter effect, including three-effect evaporation, four-effect evaporation Evaporation, five-effect evaporation and six-effect evaporation, etc.

In some embodiments of the present invention, the 1,3-propanediol fermentation broth is produced by fermentation of the genus of Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or is produced by these Produced by fermentation of genetically engineered bacteria of the genus.

According to a specific aspect of the present invention, the renewable biomass is a conventional renewable biological raw material in the field, specifically glycerol, etc.; using the renewable biomass as a raw material, Klebsiella fermentation is used to produce 1,3-propanediol The method is a conventional method in this field. In the present invention, preferably, its specific implementation method is: after the fermenter is inoculated, the temperature of the fermentation broth is controlled to be 30-40°C, the pH value is 6-7, the ventilation rate is 0.01-0.5vvm, and the stirring rate is 20-100rpm, During the fermentation process, measure the glycerol concentration of the substrate in the fermentation broth, add glycerin according to the glycerol consumption rate, ensure that the glycerol concentration in the fermentation broth is 0.5-30g/L, and put it into the tank after 30-60 hours of fermentation.

According to some preferred aspects of the present invention, in step (2), n is an integer greater than or equal to 6.

According to some preferred aspects of the present invention, in step (2), the resin used in the chromatographic separation column is a sodium-type homogeneous gel cationic chromatographic resin, which can separate component A and component A in the chromatographic column compared to other resins. Part B is easier to separate.

According to some preferred aspects of the present invention, in step (2), in the process of feed circulation, the circulation flow rate is 1-6BV/h, more preferably 2-4BV/h.

In the present invention, "BV" refers to the volume of a chromatographic separation column.

According to some preferred aspects of the present invention, in step (2), in the process of the feed cycle, the feed volume of the primary concentrated liquid is 0.05-0.3BV, more preferably 0.08-0.22BV;

In the first discharge process, the feed volume of the eluent used to push component A out is 0.1-0.42BV, more preferably 0.08-0.24BV; The feed volume of the liquid is 0.05-0.3BV, more preferably 0.08-0.22BV;

In the second discharging process, the feed volume of the eluent used to push out the remaining component B is 0.06-0.3BV, more preferably 0.08-0.22BV.

According to some preferred aspects of the present invention, in step (2), in the first discharge process, the operation of pushing out component A and component B is carried out simultaneously; and during the process of pushing out component A, close the The outlet of the next chromatographic separation column along the circulation flow direction of the chromatographic separation column enriched in component A; in the process of pushing out component B, close the next chromatographic separation column of the enriched component B along the circulation flow direction The outlet of the separation column;

In the second discharge process, during the process of pushing out the remaining component B, close the outlet of the next chromatographic separation column along the circulation flow direction of the chromatographic separation column enriched in component B in the first discharge.

According to some preferred aspects of the present invention, in step (2), when n is 6, the cycle time of the feed cycle is 6-20min, the chromatographic separation column of enrichment component A and the chromatographic separation column of enrichment component B The separation column is separated by 3 chromatographic separation columns.

According to some preferred aspects of the present invention, in step (2), the operating pressure of the chromatographic separation and desalination is 0.1-1.0 MPa, and the operating temperature is 20-60°C. Further, in step (2), the operating pressure of the chromatographic separation and desalination is 0.2-0.5 MPa, and the operating temperature is 25-55°C. Furthermore, in step (2), the operating pressure of the chromatographic separation and desalination is 0.2-0.4 MPa, and the operating temperature is 30-50°C.

According to some preferred aspects of the present invention, in step (2), the eluent is water.

According to some specific aspects of the present invention, component A also includes by-products 2,3-butanediol (BDO), glycerol, etc., and the migration speed of the three substances in the chromatographic separation column is approximately the same.

According to some specific aspects of the present invention, the salt content of component B includes acetate, succinate, and also contains protein and pigment. The migration speed of the three substances in the chromatographic separation column is approximately the same, and has different migration speed.

According to some preferred aspects of the present invention, in step (3), the concentration adopts multi-effect evaporation concentration, MVR evaporation concentration or multi-effect rectification, and the water content of the secondary concentrate is 5-45wt%.

According to some preferred aspects of the present invention, in step (3), the distillation purification is used for the purification, and the process parameters of the distillation purification are as follows: the operating pressure is 5-30mmHg, and the temperature of the distillation tower is 80-160°C.

In some embodiments of the present invention, the distillation purification process is: in the early stage, at a lower tower bottom temperature (75-85 ° C, preferably 78-82 ° C, according to a specific aspect, it can be about 80 ° C) and a higher Distill light component water and a small amount of BDO etc. under the condition of operating pressure (25-35mmHg, preferably 28-32mmHg, according to a specific aspect, can be about 30mmHg), until the basic distillation of water is completed, the temperature of the tower still rises gradually, and the continuous process begins Keep the temperature of the tower kettle at 110-120°C, and the operating pressure at 10-20mmHg. After the material feeding is completed, continue to reduce the operating pressure, and the temperature of the tower kettle continues to rise until the viscosity of the tower kettle material reaches the process requirement value of 140-160cp ( 100°C), the distillation ended. The minimum operating pressure is about 5mmHg, and the maximum temperature can reach 160°C.

Further, when it is necessary to obtain PDO and BDO products with higher purity, separation operations including rectification can be performed on the purified 1,3-propanediol product after distillation.

Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: the present invention innovatively proposes an improved method for preparing 1,3-propanediol based on the existing problems in the preparation of 1,3-propanediol, The method adopts a specific chromatographic separation and desalination process, which not only allows the PDO fermentation broth to be directly chromatographically separated and desalted after ultrafiltration in the early stage, reduces the nanofiltration membrane filtration process, and simplifies the PDO extraction process, but also PDO in the desalination process of the PDO fermentation broth The yield of the product can reach more than 98%, the desalination rate of chromatographic separation is increased to more than 90%, the distillation residue is significantly reduced, the yield of PDO product in the distillation process is increased, and the product quality is significantly improved.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is the flow chart that 1,3-propanediol fermented liquid desalination purification method adopts in the embodiment of the present invention;

Fig. 2 is the schematic diagram of the chromatographic separation system that the embodiment of the present invention adopts;

Fig. 3 is a schematic diagram of the feeding cycle process of a repeated cycle in the chromatographic separation and desalination process in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the component concentration distribution in each chromatographic separation column when the feed cycle reaches the next process in the embodiment of the present invention, that is, the first discharge;

Fig. 5 is the next procedure of procedure shown in Fig. 3 and is the schematic diagram of discharging process for the first time;

Fig. 6 is a schematic diagram of component concentration distribution in each chromatographic separation column at the end of the first discharge in the embodiment of the present invention;

Fig. 7 is a schematic diagram of the next process of the process shown in Fig. 5, that is, the second discharge process;

Fig. 8 is a schematic diagram of component concentration distribution in each chromatographic separation column at the end of the second discharge in the embodiment of the present invention;

Among them, 1. Fermentation tank; 2. 1,3-propanediol fermentation liquid; 3. Ultrafiltration device; 4. Ultrafiltration filtrate; 5. Primary evaporation dehydration device; 6. Primary steam condensate; 7. Primary concentrate; 8 1. Chromatographic separation system; 9. Eluent; 10. Raffinate phase; 11. Desalting solution; 12. Secondary evaporation and dehydration device; 13. Secondary steam condensate; 14. Secondary concentrate; 15. Distillation device; 16. Distillate; 17. Still residue; 18. Valve; 191. The first chromatographic separation column; 192. The second chromatographic separation column; 193. The third chromatographic separation column; 194. The fourth chromatographic separation column; 195. The first chromatographic separation column Fifth chromatographic separation column; 196, sixth chromatographic separation column; in the schematic structure of the valve, a circle indicates that the valve is in an open state, and a slash on the circle indicates that the valve is in a closed state.

Detailed ways

At present, in the process of preparing 1,3-propanediol by microbial fermentation, electrodialysis is usually used for desalination. With the improvement of heterogeneous membrane performance, the use cost of this technology is greatly reduced. However, in practice, the electrodialysis desalination process still has problems such as easy fouling of the membrane, a decrease in the processing capacity of the equipment, a large loss of PDO products, and an unsatisfactory desalination rate. Repeated electrodialysis desalination improves the desalination rate, but the cost is too high, which is not conducive to industrial application.

Based on the above-mentioned problems, the inventors of the present invention innovatively propose that chromatographic separation is used for the desalination of PDO fermentation broth, and the separation of substances can be realized based on the difference in the moving speed of different substances in the chromatographic resin column. However, conventional chromatographic separation methods cannot The salinity in the PDO fermented liquid is maximally removed, and there is also the problem of a large loss of the PDO product. After long-term practice and research, the inventor proposed a chromatographic separation system including n sequentially connected chromatographic separation columns, and further proposed that the chromatographic separation and desalination process should be set with a corresponding number of continuous repetition cycles according to the number of chromatographic separation columns. Then for each repeated cycle, the following processes are designed in sequence: feed cycle, first discharge and second discharge, and in the feed cycle, part of the primary concentrate is passed into the chromatographic separation system for circulating flow , until there is a chromatographic separation column enrichment component A, a chromatographic separation column enrichment component B, the component A contains 1,3-propanediol, and the component B contains salt; in the first discharge, Pass the eluent from the inlet of the chromatographic separation column enriched in component A to push component A out of the chromatographic separation column enriched in component A and collect; from the previous chromatographic separation column enriched in component B The inlet of the chromatographic separation column is fed with part of the primary concentrate, and component B is pushed out from the chromatographic separation column enriched in component B and collected; the previous chromatographic separation column is the chromatographic separation column enriched in component B along the The previous one in the opposite direction of the circulation flow direction; in the second discharge, the eluent is fed into the inlet of the eluent from the first discharge to enrich the component B in the first discharge. The remaining component B in the chromatographic separation column is released and collected;

Simultaneously control two adjacent repeating cycles, the latter repeating cycle has the following changes compared to the previous repeating cycle: In the first discharge, the chromatographic separation columns that collect component A and component B are switched along the circulation flow direction respectively. Next; in the second discharge, the chromatographic separation column that collects the remaining component B is switched to the next one along the circulation flow direction; after m repeated cycles are completed, the components A collected multiple times are mixed to obtain a desalted solution ;

The desalination rate of the desalted liquid obtained in the chromatographic separation process can reach more than 93%, and the yield of PDO in the chromatographic separation and desalination process can reach 99%.

Furthermore, by adopting the chromatographic separation and desalination method of the present invention, direct chromatographic separation and desalination of the PDO fermentation broth after ultrafiltration can reduce the nanofiltration membrane filtration process, simplify the PDO extraction process, and obtain the expected ideal effect.

Furthermore, by adopting the above-mentioned chromatographic separation and desalination method of the present invention, compared with the conventional chromatographic separation method, the concentration of the desalted liquid obtained by this method is higher, and the amount of eluent is less.

Further, as shown in Figure 1, it provides the process flow chart adopted in the desalination and purification method of 1,3-propanediol fermentation liquid in the embodiment of the present invention. 1,3-propanediol is fermented by Burgeria bacteria to obtain 1,3-propanediol fermentation liquid 2, and then ultrafiltration is performed by ultrafiltration device 3 to obtain ultrafiltration filtrate 4, which is then dehydrated and concentrated by primary evaporative dehydration device 5 to obtain primary concentrated Liquid 7, others such as primary steam condensed water 6 are discharged, and then the chromatographic separation system 8 is used to carry out chromatographic separation and desalination. The eluent 9 in the first discharge is used to elute component A, and in the second discharge, the eluent Liquid 9 is used to elute component B. After chromatographic separation and desalination, a raffinate phase 10 and a desalted liquid 11 are obtained, and then a secondary evaporation and dehydration device 12 is used to evaporate, concentrate and dehydrate the desalted liquid 11 to obtain a secondary concentrated liquid 14, a secondary The steam condensed water 13, the secondary steam condensed water 13 is discharged, and then the secondary concentrated liquid 14 is purified by a distillation device 15 to obtain a distillate 16 and a still residue 17. The distillate 16 can be further processed in other downstream processes (such as refining distillation process) for further purification.

Further, as shown in FIG. 2 , it shows a schematic structural diagram of the chromatographic separation system adopted in the embodiment of the present invention, including a first chromatographic separation column 191, a second chromatographic separation column 192, and a third chromatographic separation column connected sequentially. The column 193, the fourth chromatographic separation column 194, the fifth chromatographic separation column 195, and the sixth chromatographic separation column 196 constitute a circulation loop, and at least one valve 18 for communication is arranged between adjacent chromatographic separation columns, which can be adopted The valve 18 controls the feed or eluent, etc., and can also discharge specific components to the outside.

Further, as shown in Figure 3-8, it provides a process schematic diagram of a repeated cycle in the chromatographic separation and desalination process in the embodiment of the present invention; specifically: as shown in Figure 3, when performing chromatographic separation and desalination, through which For example, the valve between the third chromatographic separation column and the fourth chromatographic separation column can be selected to feed the fourth chromatographic separation column. After a period of circulation, when a chromatographic separation column enriches the component A, when a chromatographic separation column is enriched with component B, the circulation is stopped, and the next step of the first discharge process can be carried out. At this time, the concentration diagrams of component A and component B in each chromatographic separation column are shown in Figure 4. It can be known that at this time, the first chromatographic separation column enriched in component A is enriched with high-concentration and high-purity component A, and hardly contains component B. Similarly, the fifth column enriched in component B The chromatographic separation column is enriched with high-concentration and high-purity component B, and almost does not contain component A. This state can be obtained through multiple sampling analysis, preferably online detection by liquid chromatography, and the time node of this state can be obtained As a standard in the later repeated production process (for example, through programming, directly controlled by the program);

When carrying out the first discharge process, as shown in Figure 5, enter the eluent from the inlet of the first chromatographic separation column through the valve and close the valve between the second chromatographic separation column and the third chromatographic separation column, and the second chromatographic separation column The component A enriched in the first chromatographic separation column is released, and the high-purity component A is collected; at the same time, the inlet of the fourth chromatographic separation column is directly fed through the valve (part of the primary concentrate is used as the chromatographic separation system material) supply) and close the valve at the outlet position of the sixth chromatographic separation column, push out the component B enriched in the fifth chromatographic separation column, and collect and obtain high-purity component B; The schematic diagram of component concentration distribution is shown in Figure 6. At this time, component A in the first chromatographic separation column is basically discharged, only a small amount remains, and there is still more component B in the fifth chromatographic separation column. Therefore, It is necessary to carry out the second discharge of the next step;

When carrying out the second discharge operation, as shown in Figure 7, enter the eluent from the inlet of the first chromatographic separation column through the valve and close the valve at the outlet position of the sixth chromatographic separation column, so that the first chromatographic separation column, The second chromatographic separation column, the third chromatographic separation column, the fourth chromatographic separation column and the fifth chromatographic separation column are connected in sequence, and most of the remaining component B in the fifth chromatographic separation column is pushed out to continue to obtain high-purity component B; After the process is completed, the component concentration distribution schematic diagram in each chromatographic separation column is as shown in Figure 8. At this time, there is only a very small amount of component A in the first chromatographic separation column and almost no component B, and the fifth chromatographic separation There is only a very small amount of component B and almost no component A in the column, while the second chromatographic separation column is rich in component A and a very small amount of B relative to other chromatographic separation columns at this time, and the component in the third chromatographic separation column The contents of A and component B are basically the same. Compared with other chromatographic separation columns, the fourth chromatographic separation column is rich in component B and a small amount of A at this time, and both component A and component B in the sixth chromatographic separation column contain extremely a small amount;

After the above process, the first repeat cycle ends, based on the component concentration distribution state in each chromatographic separation column after the above process ends, the present invention further proposes that during the second repeat cycle, the feed position of the feed cycle process is not change, but has the following changes: in the first discharge of the second repeated cycle, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction; In the secondary discharge, the chromatographic separation column that collects the remaining component B is switched to the next one along the circulation flow direction; in this way, the chromatographic separation column enriched in component A can be switched to the next ( In the second repetition cycle, it is the second chromatographic separation column), so that the chromatographic separation column enriched in component B is switched to the next one along the circulation flow direction (in the second repetition cycle, it is the sixth chromatographic separation column);

When performing the number of repeated cycles corresponding to the number of chromatographic separation columns, that is, each chromatographic separation column has experienced the process of discharging, and each discharge is in the chromatogram of enriched component A or enriched component B on the separation column, thereby maximizing the separation and collection of component A and component B in the system. After m repeated cycles are completed, component A collected multiple times is mixed to obtain a desalted solution. Practice has proved that the The desalination rate in the desalination liquid can reach more than 93%, and the yield of PDO in the process of chromatographic separation and desalination can reach more than 99%.

Below in conjunction with specific embodiment above-mentioned scheme is described further; It should be understood that these embodiments are to illustrate basic principle, main feature and advantage of the present invention, and the present invention is not limited by the scope of following embodiment; Adopted in the embodiment The implementation conditions can be further adjusted according to specific requirements, and the unspecified implementation conditions are usually the conditions in routine experiments. In the following, unless otherwise stated, all raw materials are commercially available or prepared according to conventional methods in the art. In above-mentioned embodiment and comparative example, the experimental data in the table is recorded by liquid chromatography or gas chromatography respectively.

Example 1

This example provides a kind of 1,3-propanediol fermented liquid desalination purification method, described method comprises the steps:

(i) Using renewable biomass (specifically glycerol) as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth; The temperature of the fermentation broth is 37°C, the pH value is 6.5, the ventilation rate is 0.06vvm, and the stirring rate is 45rpm. During the fermentation process, the glycerol concentration of the substrate in the fermentation broth is measured, and glycerin is added according to the glycerol consumption rate to ensure that the glycerol concentration in the fermentation broth is 0.3-25g/ L, fermented for 44 hours and put into the tank;

(ii) The 1,3-propanediol fermentation broth obtained in step (i) is filtered and sterilized and concentrated successively to obtain a concentrated solution; ultrafiltration is used for filtration and sterilization, and ceramic membranes are used for ultrafiltration (ceramic membrane filtration aperture is 5nm) Concentration is carried out with a multi-effect evaporator, and the process parameters of the multi-effect evaporator are: the vacuum gauge pressure of the first-effect/second-effect/three-effect/four-effect evaporator is respectively -0.065Mpa/-0.07Mpa/-0.085Mpa/- 0.095Mpa;

(Ⅲ) adopt the chromatographic separation system shown in Figure 2 to carry out chromatographic separation and desalination with the primary concentrated solution that step (ii) obtains, chromatographic separation system comprises 6 chromatographic separation columns that circulate successively, and chromatographic separation and desalination comprises 6 continuous repetitions Cycle, the specific operation process of the first repetition cycle is shown in Figure 3-8, and the subsequent repetition cycle is carried out in the following manner: among two adjacent repetition cycles, the latter repetition cycle has the following changes compared to the previous repetition cycle : In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction; in the second discharge, the chromatographic separation columns that collect the remaining component B are respectively The circulation flow direction is switched to the next; after completing 6 repeated cycles, the components A collected multiple times are mixed to obtain the desalted solution;

Among them, the resin used in the chromatographic separation column is a sodium-type homogeneous gel cation chromatography resin (LX-1850 homogeneous gel cation chromatography resin (280-320 μm), Xi’an Lanxiao Technology New Materials Co., Ltd.); In the process, the circulation flow rate is 2.2BV/h, and the cycle time is 8min; in the process of feed circulation, the feed volume of the primary concentrate is 0.1BV; The feed volume of the eluent released by sub-A is 0.16BV, and the feed volume of the primary concentrate used to push component B out is 0.1BV; The feed volume of the eluent introduced is 0.08BV; the eluent is water; the chromatographic separation operating pressure is 0.35MPa, and the operating temperature is 30°C;

(iv) Concentrate the desalted solution obtained in step (iii) to obtain a secondary concentrate, then purify the obtained secondary concentrate to obtain 1,3-propanediol; the concentration is carried out by a multiple-effect evaporator, and the multiple-effect evaporation The process parameters of the evaporator are: the vacuum gauge pressure of the first-effect/second-effect/three-effect/four-effect evaporator is -0.065Mpa/-0.07Mpa/-0.085Mpa/-0.095Mpa respectively;

Purification adopts distillation purification. The process of distillation purification is as follows: in the early stage, light component water and a small amount of BDO are distilled under the conditions of lower tower temperature (about 80°C) and higher operating pressure (about 30mmHg). After the basic distillation of water is completed, The temperature of the tower kettle rises gradually, and starts to feed continuously. The temperature of the tower kettle is maintained at 115±5°C, and the operating pressure is 15±5mmHg. The process requirement value is 150±5cp (100°C), and the distillation is over; among them, the minimum operating pressure is about 5mmHg, and the maximum temperature can reach 160°C.

The experimental data are shown in Table 1.

Table 1 Statistical data of fermentation broth chromatographic separation and desalination

It can be seen from Table 1 that the ratio of the eluent to the primary concentrate in the chromatographic separation and desalination process is 2.4:1, and the yield of PDO reaches 97.5% (yield = (the quality of the desalted solution × the content of PDO in the desalted solution)/(primary The quality of the concentrated solution × the content of PDO in the primary concentrated solution) × 100%), the removal rate of the total salt, that is, the desalination rate reaches 91.47% (the desalination rate=(1-the quality of the desalted solution × the content of salt in the desalted solution)/ (the quality of the primary concentrate × the salt content in the primary concentrate) × 100%), the product yield and the removal rate of salt are much higher than the electrodialysis desalination process. The desalted liquid is distilled after secondary concentration, and the residual amount of the distillation pot accounts for 13.69% of the PDO output (the quality of the distillate × the content of PDO in the distillate), which is significantly reduced compared with the electrodialysis desalination process, and the PDO yield in the distillation process is increased to 98%. %.

Example 2

This example provides a kind of 1,3-propanediol fermented liquid desalination purification method, described method comprises the steps:

(i) Using renewable biomass (specifically glycerol) as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth; The temperature of the fermentation broth is 37°C, the pH value is 6.5, the ventilation rate is 0.06vvm, and the stirring rate is 45rpm. During the fermentation process, the glycerol concentration of the substrate in the fermentation broth is measured, and glycerin is added according to the glycerol consumption rate to ensure that the glycerol concentration in the fermentation broth is 0.3-25g/ L, fermented for 44 hours and put into the tank;

(ii) The 1,3-propanediol fermentation broth obtained in step (i) is filtered and sterilized and concentrated successively to obtain a concentrated solution; ultrafiltration is used for filtration and sterilization, and ceramic membranes are used for ultrafiltration (ceramic membrane filtration aperture is 5nm) Concentration is carried out with a multi-effect evaporator, and the process parameters of the multi-effect evaporator are: the vacuum gauge pressure of the first-effect/second-effect/three-effect/four-effect evaporator is respectively -0.068Mpa/-0.072Mpa/-0.086Mpa/- 0.096Mpa;

(Ⅲ) adopt the chromatographic separation system shown in Figure 2 to carry out chromatographic separation and desalination with the primary concentrated solution that step (ii) obtains, chromatographic separation system comprises 6 chromatographic separation columns that circulate successively, and chromatographic separation and desalination comprises 6 continuous repetitions Cycle, the specific operation process of the first repetition cycle is shown in Figure 3-8, and the subsequent repetition cycle is carried out in the following manner: among two adjacent repetition cycles, the latter repetition cycle has the following changes compared to the previous repetition cycle : In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction; in the second discharge, the chromatographic separation columns that collect the remaining component B are respectively The circulation flow direction is switched to the next; after completing 6 repeated cycles, the components A collected multiple times are mixed to obtain the desalted solution;

Among them, the resin used in the chromatographic separation column is sodium-type homogeneous gel cationic chromatographic resin; in the process of feed circulation, the circulation flow rate is 2.2BV/h, and the cycle time is 8min; The feed volume of the concentrate is 0.1BV;

In the process of discharging for the first time, the feed volume of the eluent used to push component A out is 0.16BV, and the feed volume of the primary concentrate used to push component B out is 0.1BV; In the process of discharging, the feed volume of the eluent used to push out the remaining component B is 0.14BV; the eluent is water; the operating pressure of the chromatographic separation is 0.25MPa, and the operating temperature is 50°C;

(iv) Concentrate the desalted solution obtained in step (iii) to obtain a secondary concentrate, then purify the obtained secondary concentrate to obtain 1,3-propanediol; the concentration is carried out by a multiple-effect evaporator, and the multiple-effect evaporation The process parameters of the evaporator are: the vacuum gauge pressure of the first-effect/second-effect/three-effect/four-effect evaporator is -0.065Mpa/-0.07Mpa/-0.085Mpa/-0.095Mpa respectively;

Purification adopts distillation purification. The process of distillation purification is as follows: in the early stage, light component water and a small amount of BDO are distilled under the conditions of lower tower temperature (about 80°C) and higher operating pressure (about 30mmHg). After the basic distillation of water is completed, The temperature of the tower kettle rises gradually, and starts to feed continuously. The temperature of the tower kettle is maintained at 115±5°C, and the operating pressure is 15±5mmHg. The process requirement value is 150±5cp (100°C), and the distillation is over; among them, the minimum operating pressure is about 5mmHg, and the maximum temperature can reach 160°C.

The experimental data are shown in Table 2.

Table 2 Statistics of fermentation broth chromatographic separation and desalination data

It can be seen from Table 2 that the ratio of the eluent to the primary concentrate in the chromatographic separation and desalination process is 3:1, the yield of PDO reaches 98.8%, the removal rate of total salt reaches 92.34%, the product yield and the removal rate of salt Much higher than the electrodialysis desalination process. The desalted liquid is distilled after secondary concentration, and the residual volume of the distillation pot accounts for 12.62% of the PDO output, which is significantly reduced compared with the electrodialysis desalination process, and the PDO yield in the distillation process is increased to 98%.

Example 3

This example provides a kind of 1,3-propanediol fermented liquid desalination purification method, described method comprises the steps:

(i) Using renewable biomass (specifically glycerol) as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth; The temperature of the fermentation broth is 37°C, the pH value is 6.5, the ventilation rate is 0.06vvm, and the stirring rate is 45rpm. During the fermentation process, the glycerol concentration of the substrate in the fermentation broth is measured, and glycerin is added according to the glycerol consumption rate to ensure that the glycerol concentration in the fermentation broth is 0.3-25g/ L, fermented for 44 hours and put into the tank;

(ii) The 1,3-propanediol fermentation broth obtained in step (i) is filtered and sterilized and concentrated successively to obtain a concentrated solution; ultrafiltration is used for filtration and sterilization, and ceramic membranes are used for ultrafiltration (ceramic membrane filtration aperture is 5nm) Carry out; Concentration adopts multi-effect evaporator to carry out, and the process parameter of described multi-effect evaporator is: the vacuum gauge pressure of one-effect/two-effect/three-effect/four-effect evaporator is respectively-0.068Mpa/-0.072Mpa/-0.086Mpa /-0.096Mpa;

(Ⅲ) adopt the chromatographic separation system shown in Figure 2 to carry out chromatographic separation and desalination with the primary concentrated solution that step (ii) obtains, chromatographic separation system comprises 6 chromatographic separation columns that circulate successively, and chromatographic separation and desalination comprises 6 continuous repetitions Cycle, the specific operation process of the first repetition cycle is shown in Figure 3-8, and the subsequent repetition cycle is carried out in the following manner: among two adjacent repetition cycles, the latter repetition cycle has the following changes compared to the previous repetition cycle : In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction; in the second discharge, the chromatographic separation columns that collect the remaining component B are respectively The circulation flow direction is switched to the next; after completing 6 repeated cycles, the components A collected multiple times are mixed to obtain the desalted solution;

Among them, the resin used in the chromatographic separation column is sodium-type homogeneous gel cationic chromatographic resin; in the process of feed circulation, the circulation flow rate is 2.2BV/h, and the cycle time is 8min; The feed volume of the concentrate is 0.1BV;

In the process of discharging for the first time, the feed volume of the eluent used to push component A out is 0.16BV, and the feed volume of the primary concentrate used to push component B out is 0.1BV; In the process of discharging, the feed volume of the eluent used to push out the remaining component B is 0.15BV; the eluent is water; the operating pressure of the chromatographic separation is 0.25MPa, and the operating temperature is 50°C;

(iv) Concentrate the desalted solution obtained in step (iii) to obtain a secondary concentrate, then purify the obtained secondary concentrate to obtain 1,3-propanediol; the concentration is carried out using a multiple-effect evaporator, and the multiple The process parameters of the effect evaporator are: the vacuum gauge pressure of the first effect/second effect/three effect/four effect evaporator is -0.065Mpa/-0.07Mpa/-0.085Mpa/-0.095Mpa respectively;

The purification adopts distillation purification, and the process of the distillation purification is: in the early stage, light component water and a small amount of BDO are distilled under the conditions of lower tower still temperature (about 80°C) and higher operating pressure (about 30mmHg), and the water is After the basic distillation is completed, the temperature of the tower kettle rises gradually, and continuous feeding starts. The temperature of the tower kettle is maintained at 115±5°C, and the operating pressure is 15±5mmHg. The viscosity of the material in the kettle reaches the process requirement value of 150±5cp (100°C), and the distillation ends; among them, the minimum operating pressure is about 5mmHg, and the maximum temperature can reach 160°C.

The experimental data are shown in Table 3.

Table 3 Statistics of Fermentation Broth Chromatographic Separation and Desalination Data

It can be seen from Table 3 that the ratio of the eluent to the primary concentrate in the chromatographic separation and desalination process is 3.1:1, the yield of PDO reaches 99%, the removal rate of total salt reaches 93.33%, the product yield and the removal rate of salt Much higher than the electrodialysis desalination process. The desalted liquid is distilled after secondary concentration, and the residual amount of the distillation pot accounts for 8.98% of the PDO output, the residual amount of the distillation pot is significantly reduced, and the PDO yield in the distillation process is increased to 99%.

Comparative example 1

Basically with embodiment 1, its difference only is: 1, also comprise nanofiltration step after ultrafiltration. The nanofiltration membrane used in the nanofiltration is MWCO500-1000; 2. The chromatographic separation desalination is replaced by electrodialysis desalination. The ion exchange membrane used in electrodialysis is an alloy membrane. The operating temperature of electrodialysis desalination is 35 ° C. Desalination after electrodialysis desalination The conductivity of the liquid is reduced to 2500 μs/cm.

The experimental data are shown in Table 4.

Table 4 Fermentation broth electrodialysis desalination data statistics

It can be seen from the above that this process not only needs to increase the nanofiltration step, but also when electrodialysis desalination is performed, the yield of PDO in the electrodialysis desalination process is 95.2%, and the removal rate of total salt is 88.5%. After the desalted liquid is concentrated, it is distilled. The residue in the distillation pot accounts for 23.5% of the PDO output, and the PDO yield during the distillation process is 96%. The residue in the distillation pot has high salt content and high viscosity, and scraper evaporation is required to recover the PDO and part of the glycerin. .

Comparative example 2

Basically the same as Example 1, the only difference is: calcium-type homogeneous gel cation chromatography resin (LX-1850 calcium-type homogeneous gel cation chromatography resin (280-300 μm), Xi'an Lanxiao Technology New Materials Co., Ltd.).

The experimental data are shown in Table 5.

Table 5 Fermentation broth electrodialysis desalination data statistics

It can be seen from Table 5 that under the condition that the ratio of the eluent to the primary concentrate in the chromatographic separation and desalination process is 2.4:1, when the resin type is homogeneous gel cationic chromatographic resin (calcium type), the PDO in the chromatographic separation and desalination process The yield is only 93%, the total salt removal rate is 91.72%, and the desalted liquid is distilled after secondary concentration, and the residue of the distillation still accounts for 14.38% of the PDO output.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (18)

1. A method for desalting and purifying 1,3-propanediol fermentation liquid, producing 1,3-propanediol by microbial fermentation to obtain 1,3-propanediol fermentation liquid, characterized in that the purification method comprises the following steps:

   (1) sterilizing and concentrating the 1,3-propanediol fermentation broth sequentially to obtain a primary concentrate;

   (2) Carrying out chromatographic separation and desalination of the primary concentrate obtained in step (1) by using a chromatographic separation system, the chromatographic separation system comprising n sequentially connected chromatographic separation columns, where n is an integer greater than or equal to 3;

   The chromatographic separation and desalination includes m continuous repetition periods, m and n are the same; wherein, the following procedures are performed sequentially in each repetition period:

   Feed cycle: pass part of the primary concentrated liquid into the chromatographic separation system for circulation until a chromatographic separation column enriches component A, and a chromatographic separation column enriches component B, and the component A contains 1 , 3-propanediol, the component B contains salt;

   The first discharge: from the entrance of the chromatographic separation column enriched in component A, the eluent is introduced to push component A out of the chromatographic separation column enriched in component A, and collect;

   Part of the primary concentrate is introduced from the inlet of the previous chromatographic separation column of the chromatographic separation column enriched in component B, and component B is pushed out from the chromatographic separation column enriched in component B for collection; the previous chromatographic separation The column is the previous one in the opposite direction of the chromatographic separation column enriched in component B along the circulation flow direction;

   Wherein, the operation of pushing out component A and component B is carried out simultaneously, and in the process of pushing out component A, close the outlet of the next chromatographic separation column of the chromatographic separation column of this enrichment component A along the circulation flow direction; During the process of pushing out component B, close the outlet of the next chromatographic separation column along the circulation flow direction of the chromatographic separation column enriched in component B;

   The second discharge: the eluent is fed into the inlet of the eluent from the first discharge, and the remaining component B in the chromatographic separation column enriched in component B in the first discharge is pushed out , collect; wherein, in the process of pushing out the remaining component B, close the outlet of the next chromatographic separation column of the chromatographic separation column enriched in component B in the discharge for the first time along the circulation flow direction;

   Controlling that the feed position of the feed cycle process remains unchanged in two adjacent repeat cycles, the latter repeat cycle has the following changes compared to the previous repeat cycle:

   In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction;

   In the second discharge, the chromatographic separation columns that collect the remaining component B are all switched to the next one along the circulation flow direction;

   After completing m repetition periods, mix the components A collected multiple times to obtain a desalted solution;

   (3) Concentrating the desalted solution obtained in step (2) to obtain a secondary concentrate, and then purifying the obtained secondary concentrate to obtain 1,3-propanediol.
2. A method for desalting and purifying 1,3-propanediol fermentation liquid, producing 1,3-propanediol by microbial fermentation to obtain 1,3-propanediol fermentation liquid, characterized in that the purification method comprises the following steps:

   (1) sterilizing and concentrating the 1,3-propanediol fermentation broth sequentially to obtain a primary concentrate;

   (2) Chromatographic separation and desalination of the primary concentrated solution obtained in step (1) is carried out by using a chromatographic separation system. The resin used in the column is a sodium-type homogeneous gel cationic chromatography resin;

   The chromatographic separation and desalination includes m continuous repetition periods, m and n are the same; wherein, the following procedures are performed sequentially in each repetition period:

   Feed cycle: pass part of the primary concentrated liquid into the chromatographic separation system for circulation until a chromatographic separation column enriches component A, and a chromatographic separation column enriches component B, and the component A contains 1 , 3-propanediol, the component B contains salt;

   The first discharge: from the entrance of the chromatographic separation column enriched in component A, the eluent is introduced to push component A out of the chromatographic separation column enriched in component A, and collect;

   Part of the primary concentrate is introduced from the inlet of the previous chromatographic separation column of the chromatographic separation column enriched in component B, and component B is pushed out from the chromatographic separation column enriched in component B for collection; the previous chromatographic separation The column is the previous one in the opposite direction of the chromatographic separation column enriched in component B along the circulation flow direction;

   The second discharge: the eluent is fed into the inlet of the eluent from the first discharge, and the remaining component B in the chromatographic separation column enriched in component B in the first discharge is pushed out ,collect;

   Controlling two adjacent repeating periods, the latter repeating period has the following changes compared to the previous repeating period:

   In the first discharge, the chromatographic separation columns that collect component A and component B are respectively switched to the next one along the circulation flow direction;

   In the second discharge, the chromatographic separation columns that collect the remaining component B are all switched to the next one along the circulation flow direction;

   After completing m repetition periods, mix the components A collected multiple times to obtain a desalted solution;

   (3) Concentrating the desalted solution obtained in step (2) to obtain a secondary concentrate, and then purifying the obtained secondary concentrate to obtain 1,3-propanediol.
3. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, characterized in that, in step (2), n is an integer greater than or equal to 6.
4. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 2, characterized in that in step (2), the feeding position of the feeding circulation process is kept unchanged during the control of two adjacent repeated cycles.
5. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 2, characterized in that in step (2), the resin used in the chromatographic separation column is a sodium-type homogeneous gel cationic chromatographic resin.
6. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, characterized in that, in step (2), in the process of feeding circulation, the circulation flow rate is 1-6BV/h.
7. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 6, characterized in that, in step (2), in the process of feeding circulation, the circulation flow rate is 2-4BV/h.
8. [Corrected 22.08.2022 under Rule 26]
   

   According to claim 1 or 2 described 1,3-propanediol fermented liquid desalination purification method, it is characterized in that, in step (2), in the operation of described feed circulation, the feed volume of the primary concentrated solution that passes through is 0.05-0.3BV;

   In the process of the first discharge, the feed volume of the eluent used to push component A out is 0.1-0.42BV, and the feed volume of the primary concentrate used to push component B out is 0.05-0.05BV. 0.3BV;

   In the second discharge process, the feed volume of the eluent used to push out the remaining component B is 0.06-0.3BV.
   
   
9. [Corrected 22.08.2022 under Rule 26]
   

   The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 8, characterized in that, in step (2), in the operation of the feed cycle, the feed volume of the primary concentrated solution that is passed in is 0.08- 0.22BV;

   In the first discharge process, the feed volume of the eluent used to push component A out is 0.1-0.24BV, and the feed volume of the primary concentrate used to push component B out is 0.08-0.08- 0.22BV;

   In the second discharge process, the feed volume of the eluent used to push out the remaining component B is 0.08-0.22BV.
10. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 2, characterized in that, in step (2), in the operation of the first discharge, the operation of pushing out component A and component B is simultaneously Carry out; and in the process of pushing out component A, close the outlet of the next chromatographic separation column of the chromatographic separation column enriched in component A along the circulation flow direction; in the process of pushing out component B, close the enrichment group The outlet of the next chromatographic separation column along the circulating flow direction of the chromatographic separation column of B;

    In the second discharge process, during the process of pushing out the remaining component B, close the outlet of the next chromatographic separation column along the circulation flow direction of the chromatographic separation column enriched in component B in the first discharge.
11. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, wherein in step (2), when n is 6, the cycle time of the feed cycle is 6-20min, rich The chromatographic separation column for collecting component A and the chromatographic separation column for enriching component B are separated by 3 chromatographic separation columns.
12. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, wherein in step (2), the operating pressure of the chromatographic separation and desalting is 0.1-1.0 MPa, and the operating temperature is 20-60 ℃.
13. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 12, characterized in that in step (2), the operating pressure of the chromatographic separation and desalting is 0.2-0.5 MPa, and the operating temperature is 25-55°C.
14. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 13, characterized in that in step (2), the operating pressure of the chromatographic separation and desalting is 0.2-0.4 MPa, and the operating temperature is 30-50°C.
15. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, characterized in that, in step (2), the eluent is water.
16. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, characterized in that, in step (1), ultrafiltration is used for the filter sterilization;

    The concentration adopts multi-effect evaporation concentration, MVR evaporation concentration or multi-effect rectification, and the water content of the primary concentrate is 50-70wt%.
17. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, characterized in that, the specific implementation method for producing 1,3-propanediol by microbial fermentation is: after the fermenter is inoculated, the temperature of the fermentation broth is controlled to be 30 -40°C, pH value 6-7, ventilation rate 0.01-0.5vvm, stirring rate 20-100rpm, measure the concentration of substrate glycerol in the fermentation broth during the fermentation process, add glycerin according to the glycerol consumption rate to ensure the glycerol in the fermentation broth The concentration is 0.5-30g/L, and it is put into the tank after 30-60 hours of fermentation.
18. The method for desalting and purifying 1,3-propanediol fermentation broth according to claim 1 or 2, wherein in step (3), the concentration adopts multi-effect evaporation concentration, MVR evaporation concentration or multi-effect rectification. The water content of the concentrated solution is 5-45wt%;

    The purification adopts distillation purification, and the process parameters of the distillation purification are as follows: the operating pressure is 5-30mmHg, and the temperature of the distillation tower is 80-160°C.

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