WO2023010982A1

WO2023010982A1 - Preparation method for bio-based 1,3-propanediol

Info

Publication number: WO2023010982A1
Application number: PCT/CN2022/096616
Authority: WO
Inventors: 罗吉安; 张叶兴; 张赟; 石国柱; 刘宾; 张昊; 陈利亮
Original assignee: 苏州苏震生物工程有限公司
Priority date: 2021-08-02
Filing date: 2022-06-01
Publication date: 2023-02-09
Also published as: CN113337548A; CN113337548B

Abstract

Provided is a preparation method for bio-based 1,3-propanediol, comprising: using renewable biomass as a raw material, using Klebsiella fermentation to produce 1,3-propanediol, obtaining a 1,3-propanediol fermentation broth, and then successively performing ultrafiltration, nanofiltration, electrodialysis and multiple-effect evaporation in sequence, then employing a first distillation column to perform dewatering and distillation, employing a first decolorization column to adsorb and decolorize a distillate, separating a dealcoholized liquid containing 1,3-propanediol in a second distillation column, producing crude 1,3-propanediol in a third distillation column, and employing a second decolorization tower to perform activated carbon adsorption decolorization of the crude 1,3-propanediol, the activated carbon in the first decolorization tower being a second utilization of the activated carbon after decolorization of the crude 1,3-propanediol. The purity of 1,3-propanediol prepared by the present method can exceed 99.9%, the color thereof is ≤10 Hazen, and there is no peculiar smell. 270 nm absorbance of the 1,3-propanediol product is ≤0.08, and the activated carbon utilization rate is high.

Description

A kind of preparation method of bio-based 1,3-propanediol

technical field

The invention relates to the technical field of preparation of bio-based new materials, in particular to a preparation method of bio-based 1,3-propanediol.

Background technique

1,3-Propanediol (PDO) is an important chemical raw material, such as the key raw material for the synthesis of memory fiber polytrimethylene terephthalate (PTT). Compared with chemical synthesis, the advantages of fermentative production of 1,3-propanediol are high selectivity and mild operating conditions. The influence of conditions is easy to produce by-products, and the existence of these by-products not only makes 1,3-propanediol products colored but also affects the application of 1,3-propanediol products, especially for synthetic memory fiber polyterephthalic acid The process of propylene glycol ester (PTT) has a great influence; therefore, in order to obtain qualified 1,3-propanediol products, it is necessary to carry out decolorization treatment. At present, the decolorization process commonly used has activated carbon decolorization, and specifically adopts granular activated carbon to extract from the final rectification. The crude product of 1,3-propanediol is decolorized by adsorption, but in current practice, the consumption of activated carbon is relatively large, which can account for 4-5% of the final product quality, and the cost of decolorization is relatively high.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, to provide a kind of improved can greatly reduce the used gac consumption of decolouring and can have the purity more than 99.9%, chromaticity≤10 black Zeng, no peculiar smell and uv-absorbing value ( 270nm) ≤ 0.08 bio-based 1,3-propanediol preparation method.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for preparing bio-based 1,3-propanediol, the method for preparing bio-based 1,3-propanediol is a batch-type preparation process, which includes:

(1) Using renewable biomass as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth;

(2) performing ultrafiltration, nanofiltration, electrodialysis, and multi-effect evaporation in sequence to obtain 1,3-propanediol concentrate;

(3) The concentrated solution is dehydrated by the first rectifying tower to obtain a dehydration liquid, and the dehydration liquid is distilled to obtain a 1,3-propanediol distillate;

(4) adopting the first decolorization tower to carry out adsorption decolorization to 1,3-propanediol distillate;

(5) The decolorized liquid obtained after decolorization in step (4) is rectified in the second rectification tower, and 2,3-butanediol is separated from the top of the tower, and 1,3-propanediol is extracted from the bottom of the tower still. The dealcoholized liquid is rectified in the third rectifying tower, and the 1,3-propanediol crude product is extracted from the tower top;

(6) Using the second decolorization tower to decolorize the crude 1,3-propanediol by activated carbon adsorption to obtain purified 1,3-propanediol;

(7) Replace part or all of the activated carbon in the first decolorization tower with the activated carbon after decolorizing the crude product of 1,3-propanediol in the second decolorization tower, and add new activated carbon in the second decolorization tower for the next batch of bio-based Preparation of 1,3-propanediol.

According to some preferred aspects of the present invention, in step (4), the residence time of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 2-48 hours. Further, in step (4), the residence time of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 10-30 hours.

According to some preferred aspects of the present invention, in step (4), the decolorization temperature of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 20-80°C.

According to some preferred aspects of the present invention, in step (5), the process parameters of the second rectification tower are: the number of theoretical plates of the rectification tower is 30-100, the operating pressure at the top of the tower is 1-30mmHg, and the reflux ratio is 2.5-30. Further, in step (5), the process parameters of the second rectification tower are: the operating pressure at the top of the tower is 15-25 mmHg, and the reflux ratio is 2.5-10.

According to some preferred aspects of the present invention, in step (5), the process parameters of the third rectification tower are: the number of theoretical plates of the rectification tower is 20-80, the operating pressure at the top of the tower is 1-20mmHg, and the reflux ratio is 1-6. Further, in step (5), the process parameters of the third rectification tower are: the operating pressure at the top of the tower is 2-10 mmHg, and the reflux ratio is 3-6.

According to some preferred aspects of the present invention, in step (6), the residence time of the crude 1,3-propanediol in the second decolorization tower is controlled to be 5-48 hours. Further, in step (6), the residence time of the crude 1,3-propanediol product in the second decolorization tower is controlled to be 15-40 hours.

According to some preferred aspects of the present invention, in step (6), the decolorization temperature of the crude 1,3-propanediol in the second decolorization tower is controlled to be 20-80°C.

According to some preferred aspects of the present invention, in step (6), the particle size of the activated carbon in the second decolorization tower is 10-80 mesh.

According to the present invention, in step (6), the purity of the purified 1,3-propanediol is greater than or equal to 99.9%, the chromaticity is less than or equal to 10 Hazen, no peculiar smell, and the ultraviolet light absorption value at 270nm is less than or equal to 0.08.

According to the present invention, in step (7), in terms of mass percentage, the new activated carbon added in the second decolorization tower accounts for 1.5-2.5% of the purified 1,3-propanediol prepared in the next batch.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

The present invention aims at the problem that by-products are easily produced in the process of producing 1,3-propanediol by the existing biological fermentation method, which affects the product color and product application, and innovatively provides an improved preparation method of bio-based 1,3-propanediol. This method is based on the analysis and research carried out by the inventors of the present invention on the process of adsorption and decolorization. The chromaticity of the crude 1,3-propanediol obtained after rectification can be reduced to about 40 black Zeng, and then more activated carbon is used to adsorb the pigment by-products After that, the chromaticity can be reduced to less than 10 black Zeng, and the by-product carbonyl compounds can also be absorbed and reduced (the content of carbonyl compounds can be characterized by ultraviolet light absorption, and studies have shown that the presence of carbonyl compounds will significantly affect the intrinsic viscosity of PTT slices. , slice color, etc.), but the study found that although the ability of activated carbon to adsorb carbonyl compounds after adsorbing crude PDO has approached saturation, it still has a high adsorption capacity for pigments, and it is practical to directly discard the activated carbon after use. It is a kind of waste; at the same time, for the analysis of the whole process, there are more by-product pigments in the distillate obtained through fermentation and a series of operations. At this time, there are more pigments and are easily adsorbed by activated carbon, which not only fully exerts the adsorption capacity of the activated carbon after the adsorption operation, but also significantly reduces the color of the distillate, and also reduces the output of the third rectifying tower. The content of impurity such as pigment in the PDO crude product that goes out, reduces the load of final tail adsorption tower, thereby significantly reduced the consumption of activated carbon in PDO preparation process (the present invention is about 1.5-2.5% of final product quality, reduces compared with existing consumption More than about 40%), improved the quality of PDO product simultaneously.

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 schematic diagram of the technological process adopted in the preparation method of 1-3 bio-based 1,3-propanediol of the present invention;

Among them, 1. fermentation tank; 2. 1,3-propanediol fermentation liquid; 3. ultrafiltration device; 4. ultrafiltration filtrate; 5. nanofiltration device; 6. nanofiltration filtrate; 7. electrodialysis device; 8. electric Dialysis desalination liquid; 9. Multi-effect evaporator; 10. 1,3-propanediol concentrate; 11. First rectification tower; 12. Dehydration liquid; 13. Distillation device; 14. 1,3-propanediol distillate; 15 , the first decolorizing tower; 16, decolorizing liquid; 17, the second rectifying tower; 18, 2,3-butanediol (BDO); 19, dealcoholizing liquid; 20, the third rectifying tower; 21, 1, 3-propanediol crude product; 22, the second decolorization tower; 23, 1,3-propanediol product.

Detailed ways

At present, although the production of 1,3-propanediol by fermentation can obtain 1,3-propanediol with high selectivity, it should be due to the process conditions that unexpected by-products are likely to be produced in the process. The existence of the product has already affected the color of the product and its application prospects, and the existing common method is to use activated carbon for final adsorption decolorization, but in current practice, the consumption of activated carbon is relatively large, which can account for 4-5% of the final product quality. %, the cost of decolorization is higher.

Based on the above problems, the present application innovatively provides a method for preparing bio-based 1,3-propanediol. The method for preparing bio-based 1,3-propanediol is a batch-type preparation process, including:

The method is based on the inventor's long-term research in the field of 1,3-propanediol (PDO) production technology, specifically the analysis and research on the process of adsorption decolorization, and further studies on the pigment and carbonyl in the by-products of the adsorption decolorization process. The adsorption process and effect of compounds. Based on the discovery that although the carbonyl compound adsorption capacity of activated carbon after adsorbing crude PDO is close to saturation, it still has a relatively high adsorption capacity for pigments. The distillate contains a lot of by-product pigments, and the original used activated carbon is directly discarded instead of secondary use, and the distillate is initially adsorbed and decolorized, so that the amount of new activated carbon used in the decolorization and adsorption at the end of the process is reduced. It is greatly reduced and at least reduced by about 40% compared with the prior art (the usage amount is about 1.5-2.5% of the quality of the final product), which greatly saves the cost and guarantees or even improves the quality of the PDO product.

Further, in step (1), the renewable biomass is a conventional renewable biological raw material in the field, specifically glycerol, etc.; the renewable biomass is used as a raw material to produce 2,3- The method for butanediol is a conventional method in the art. In the present invention, preferably, its specific implementation method is: after the fermenter is inoculated, control the temperature of the fermentation liquid to 30-40°C, the pH value to 6-7, the ventilation rate to 0.01-0.5vvm, and the stirring rate to 20-100rpm. Substrate glycerol concentration in the fermentation broth, add glycerin according to the consumption rate of glycerol to ensure that the glycerin concentration in the fermentation broth is 0.5-30g/L, and put it into the tank after 30-60 hours of fermentation.

Further, in step (2), the ultrafiltration is carried out with a ceramic membrane for sterilization and protein removal, and the filter aperture of the ceramic membrane is 5nm-50nm; the molecular weight cut-off of the nanofiltration membrane used in the nanofiltration is 300D- 1000D, used to remove protein and part of the salt; the ion exchange membrane used in the electrodialysis is a heterogeneous membrane or a semi-homogeneous membrane, and the conductivity of the desalted solution is reduced to 2000μs/cm after the electrodialysis desalination; the multi-effect evaporation uses Multi-effect evaporator, the multi-effect evaporator is a three-effect evaporator, four-effect evaporator, five-effect evaporator, six-effect evaporator or seven-effect evaporator, and it is decompression evaporation, the operation of the final effect evaporator The pressure is -0.093～-0.099MPa.

Further, in step (2), the water content of the 1,3-propanediol concentrate is controlled to be less than or equal to 40%.

Further, in step (3), the process parameters of the first rectification tower are: the number of theoretical plates of the rectification tower is 10-50, the operating pressure at the top of the tower is 80-95mmHg, and the reflux ratio at the top of the tower is 0.5-1 ; The preferred operating pressure at the top of the tower is 85-92mmHg. At the same time, the moisture content of the dehydration liquid is controlled to be less than or equal to 0.5%.

Further, in step (3), the process parameters of the distillation are: the operating pressure at the top of the tower is 3-20mmHg.

Further, in step (4), the residence time of the control 1,3-propanediol distillate in the first decolorization tower is 2-48 hours, preferably controlling the residence time of the 1,3-propanediol distillate in the first decolorization tower for 10-30 hours. At the same time, the decolorization temperature of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 20-80°C.

Further, in step (5), the process parameters of the second rectification tower are: the number of theoretical plates of the rectification tower is 30-100, the operating pressure at the top of the tower is 1-30mmHg, and the reflux ratio is 2.5-30; preferably The operating pressure at the top of the tower is 15-25mmHg, and the reflux ratio is 2.5-10.

Further, in step (5), the process parameters of the third rectification tower are: the number of theoretical plates of the rectification tower is 20-80, the operating pressure at the top of the tower is 1-20 mmHg, and the reflux ratio is 1-6. Preferably, the operating pressure at the top of the tower is 2-10 mmHg, and the reflux ratio is 3-6.

Further, in step (6), the residence time of the crude 1,3-propanediol in the second decolorization tower is controlled to be 5-48 hours. Preferably, the residence time of the crude 1,3-propanediol in the second decolorization tower is controlled to be 15-40 hours. At the same time, control the decolorization temperature of the crude 1,3-propanediol in the second decolorization tower to be 20-80°C.

According to some embodiments of the present invention, in step (6), the activated carbon used in the second decolorization tower of the present invention can be commercially available activated carbon, and its particle size is approximately 10-80 mesh.

Further, as shown in Figure 1, it provides the process flow chart adopted by the preparation method of bio-based 1,3-propanediol of the present invention, in the fermentor 1, renewable biomass is used as raw material, and Klebsiella 1,3-propanediol is fermented to obtain 1,3-propanediol fermentation liquid 2, which is then successively passed through ultrafiltration device 3 for ultrafiltration to obtain ultrafiltration filtrate 4, nanofiltration device 5 for nanofiltration to obtain nanofiltration filtrate 6, and electrofiltration The dialysis device 7 performs electrodialysis to obtain an electrodialysis desalination solution 8, and the multi-effect evaporator 9 performs multi-effect evaporation to obtain a 1,3-propanediol concentrate 10, and then uses the first rectification column 11 to demineralize the 1,3-propanediol concentrate 10 is dehydrated to obtain a dehydration liquid 12, and then the dehydration liquid 12 is distilled through a distillation device 13 to obtain a 1,3-propanediol distillate 14, and then the first decolorization tower 15 is used to absorb and decolorize the 1,3-propanediol distillate 14, Obtain the decolorized liquid 16; the decolorized liquid 16 obtained after decolorization is rectified in the second rectifying tower 17, and 2,3-butanediol (BDO) 18 is separated from the top of the tower, and the extract containing 1 , the dealcoholization liquid 19 of 3-propanediol, the dealcoholization liquid 19 is rectified in the third rectification tower 20, extracts 1,3-propanediol crude product (PDO crude product) 21 from tower top, adopts the second decolorization tower 22 to The crude 1,3-propanediol product 21 is decolorized by activated carbon adsorption to obtain a purified 1,3-propanediol product (PDO product) 23 .

The purity of the purified 1,3-propanediol obtained by the above method of the present invention can be greater than or equal to 99.9%, the chroma is less than or equal to 10 black, no peculiar smell, and the ultraviolet light absorption value at 270nm is less than or equal to 0.08, and the new activated carbon consumption in the decolorization tower of this method The amount is small, about 1.5-2.5% of the final product mass.

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.

Example 1

This example provides a method for preparing bio-based 1,3-propanediol. The method for preparing bio-based 1,3-propanediol is a batch-type preparation process. The preparation method includes the following steps:

(1) Using renewable biomass (specifically glycerol) as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation liquid; the specific implementation method is:

After inoculation in the fermenter, control the temperature of the fermentation broth to 37°C, pH value to 6.5, ventilation rate to 0.06vvm, and stirring rate to 45rpm. During the fermentation process, measure the concentration of substrate glycerol in the fermentation broth, and add glycerol according to the consumption rate of glycerol to ensure that the glycerol in the fermentation broth The concentration is 0.3-25g/L, fermented for 44 hours and put into the tank;

(2) the 1,3-propanediol fermentation broth obtained in step (1) is carried out successively:

Ultrafiltration for sterilization and protein removal to obtain ultrafiltration filtrate, the ultrafiltration adopts ceramic membrane (ceramic membrane filtration pore size is 5nm) to carry out;

Nanofiltration for protein and partial salt removal to obtain nanofiltration filtrate, the nanofiltration membrane used in the nanofiltration is MWCO500-1000;

Electrodialysis for desalination to obtain electrodialysis desalination solution, the process parameters of the electrodialysis are: the ion exchange membrane used is a heterogeneous membrane, and the conductivity of the desalination solution is reduced to 1800 μs/cm after electrodialysis desalination;

Multi-effect evaporation used to remove part of the water to obtain 1,3-propanediol concentrate; the multi-effect evaporation is carried out using a multi-effect evaporator, and the process parameters of the multi-effect evaporator are: four-effect evaporator, final effect The operating pressure of the evaporator is -0.095MPa;

(3) dehydrating the concentrated solution obtained in step (2) using a first rectification tower to obtain a dehydrated liquid, and then distilling the dehydrated liquid to obtain a 1,3-propanediol distillate;

Wherein, the process parameters of the first rectifying tower are: the operating pressure at the top of the tower is 88-90mmHg, and the reflux ratio at the top of the tower is 0.5;

The technical parameter of described distillation is: distillation column operating pressure is 10-12mmHg;

(4) The 1,3-propanediol distillate obtained in step (3) is adsorbed and decolorized by the first decolorizing tower, and the residence time of the distillate in the first decolorizing tower is 15 hours;

Wherein the activated carbon in the first decolorization tower is the activated carbon after the second decolorization tower of the previous batch completed the decolorization of the crude product of 1,3-propanediol;

(5) The decolorized liquid obtained in step (4) is rectified in the second rectification tower, and 2,3-butanediol is separated from the top of the tower, and the decolorized liquid containing 1,3-propanediol is extracted from the bottom of the tower still. Alcoholic liquid, rectification in the third rectification tower with the dealcoholized liquid extracted from the bottom of the tower kettle, and extract 1,3-propanediol crude product from the top of the tower;

Wherein, the process parameters of the second rectifying tower are: the operating pressure at the top of the tower is 17-18mmHg, and the reflux ratio is 3.1;

The technological parameter of described the 3rd rectifying tower is: tower top operating pressure is 5-6mmHg, and reflux ratio is 4.8;

(6) adopting the second decolorization tower to absorb crude 1,3-propanediol to obtain a purified 1,3-propanediol product;

Wherein, the residence time of the 1,3-propanediol crude product in the second decolorization tower is 20 hours, wherein the activated carbon in the second decolorization tower is new activated carbon.

The experimental data of this example are shown in Table 1.

Table 1

It can be seen from Table 1 that in the final product 1,3-propanediol produced in this example, the purity of 1,3-propanediol is 99.95%, the chromaticity is 5 black, no peculiar smell, and the ultraviolet absorption value at 270nm is 0.04. In this example, the amount of new activated carbon consumed by the second decolorization tower is 0.52 tons, and the total consumption of new activated carbon accounts for 2% of the quality of the prepared 1,3-propanediol product.

Example 2

After inoculation in the fermenter, control the temperature of the fermentation broth to 37°C, pH value to 6.5, ventilation rate to 0.06vvm, and stirring rate to 45rpm. During the fermentation process, measure the concentration of substrate glycerol in the fermentation broth, and add glycerol according to the consumption rate of glycerol to ensure that the glycerol in the fermentation broth The concentration is 0.3-25g/L, fermented for 48 hours and put into the tank;

Electrodialysis for desalination to obtain electrodialysis desalination solution, the process parameters of the electrodialysis are: the ion exchange membrane used is a heterogeneous membrane, and the conductivity of the desalination solution is reduced to 2000 μs/cm after electrodialysis desalination;

Multi-effect evaporation used to remove part of the water to obtain 1,3-propanediol concentrate; the multi-effect evaporation is carried out using a multi-effect evaporator, and the process parameters of the multi-effect evaporator are: four-effect evaporator, final effect The operating pressure of the evaporator is -0.096MPa;

Wherein, the process parameters of the first rectifying tower are: the operating pressure at the top of the tower is 90-91mmHg, and the reflux ratio at the top of the tower is 1;

The technical parameter of described distillation is: distillation column operating pressure is 10-11mmHg;

(5) The first decolorized liquid obtained in step (4) is rectified in the second rectification tower, and 2,3-butanediol is separated from the top of the tower, and 1,3-propanediol is extracted from the bottom of the tower still. The dealcoholized liquid, the dealcoholized liquid taken from the bottom of the tower still is rectified in the third rectifying tower, and the crude product of 1,3-propanediol is taken out from the top of the tower;

Wherein, the process parameters of the second rectifying tower are: the operating pressure at the top of the tower is 17-19mmHg, and the reflux ratio is 2.8;

The technological parameter of described the 3rd rectifying tower is: tower top operating pressure is 5-6mmHg, and reflux ratio is 5;

Wherein, the residence time of 1,3-propanediol crude product in the second decolorization tower is 20 hours, and the gac in the second decolorization tower is new gac.

The experimental data of this example are shown in Table 2.

Table 2

It can be seen from Table 2 that in the final product 1,3-propanediol produced in this example, the purity of 1,3-propanediol is 99.95%, the chromaticity is 5 black, no peculiar smell, and the ultraviolet absorption value at 270nm is 0.06. In this example, the amount of new activated carbon consumed by the second decolorization tower is 0.58 tons, and the quality of new activated carbon consumed in total accounts for 2.3% of the quality of the prepared 1,3-propanediol product.

Example 3

After inoculation in the fermenter, control the temperature of the fermentation broth to 37°C, pH value to 6.5, ventilation rate to 0.06vvm, stirring rate to 45rpm, measure the concentration of substrate glycerol in the fermentation broth during the fermentation process, and add glycerol according to the glycerol consumption rate to ensure that the glycerol in the fermentation broth The concentration is 0.3-25g/L, fermented for 48 hours and put into the tank;

(4) The 1,3-propanediol distillate obtained in step (3) is adsorbed and decolorized by the first decolorizing tower, and the residence time of the distillate in the first decolorizing tower is 20 hours;

Wherein, the residence time of the 1,3-propanediol crude product in the second decolorization tower is 20 hours, and the activated carbon in the second decolorization tower is new activated carbon.

The experimental data of this example are shown in Table 3.

table 3

It can be seen from Table 3 that in the final product 1,3-propanediol produced in this example, the purity of 1,3-propanediol is 99.95%, the color is 5 black, no peculiar smell, and the ultraviolet light absorption value at 270nm is 0.05. In this example, the amount of new activated carbon consumed by the second decolorization tower is 0.59 tons, and the total consumption of new activated carbon accounts for 2.21% of the quality of the prepared 1,3-propanediol product.

Comparative example 1

After inoculation in the fermenter, control the temperature of the fermentation broth to 37°C, pH value to 6.5, ventilation rate to 0.06vvm, and stirring rate to 45rpm. During the fermentation process, measure the concentration of substrate glycerol in the fermentation broth, and add glycerol according to the consumption rate of glycerol to ensure that the glycerol in the fermentation broth The concentration is 0.3-25g/L, fermented for 40 hours and put into the tank;

Wherein, the process parameters of the first rectifying tower are: the operating pressure at the top of the tower is 89-90mmHg, and the reflux ratio at the top of the tower is 1;

Wherein the activated carbon in the first decolorization tower is new activated carbon;

Wherein, the process parameters of the second rectifying tower are: the operating pressure at the top of the tower is 18-19mmHg, and the reflux ratio is 3;

The experimental data of this example are shown in Table 4.

Table 4

It can be seen from Table 4 that in the final product 1,3-propanediol produced in this example, the purity of 1,3-propanediol is 99.95%, the chromaticity is 5 black, no peculiar smell, and the ultraviolet absorption value at 270nm is 0.02. In this example, the amount of activated carbon consumed by the first decolorization tower and the second decolorization tower is 0.81 tons and 0.41 tons respectively, and the total consumption of new activated carbon accounts for 4.5% of the quality of the prepared 1,3-propanediol product.

Comparative example 2

Be used for the ultrafiltration of sterilizing and removing protein, obtain ultrafiltration filtrate, described ultrafiltration adopts ceramic membrane (ceramic membrane filtration aperture is 5nm) to carry out;

(4) The 1,3-propanediol distillate obtained in step (3) is rectified in the second rectification tower, and the 2,3-butanediol is separated from the top of the tower, and the 1,3-butanediol is extracted from the bottom of the tower still containing 1, The dealcoholization liquid of 3-propanediol, the dealcoholization liquid extracted from the bottom of the tower kettle is rectified in the third rectification tower, and the crude product of 1,3-propanediol is extracted from the top of the tower;

(5) Adopting a decolorization tower to absorb crude 1,3-propanediol to obtain a purified 1,3-propanediol product;

Wherein, the residence time of the 1,3-propanediol crude product in the second decolorization tower is 20 hours, and the activated carbon in the decolorization tower is new activated carbon.

The experimental data of this example are shown in Table 5.

table 5

It can be seen from Table 5 that in the final product 1,3-propanediol produced in this example, the purity of 1,3-propanediol is 99.95%, the chromaticity is 5 black, no peculiar smell, and the ultraviolet light absorption value at 270nm is 0.065. In this example, the amount of activated carbon consumed by the decolorization tower is 0.99 tons, and the total consumption of new activated carbon accounts for 4% of the quality of the prepared 1,3-propanediol product.

In the above examples and comparative examples, the experimental data in the table were measured by liquid chromatography or gas chromatography, and the ultraviolet absorbance was measured by an ultraviolet spectrophotometer.

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

A method for preparing bio-based 1,3-propanediol, characterized in that the method for preparing bio-based 1,3-propanediol is a batch-type preparation process, and the preparation method includes the following steps:

(1) Using renewable biomass as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth;

(2) The 1,3-propanediol fermentation broth obtained in step (1) is sequentially subjected to ultrafiltration for sterilization and protein removal, nanofiltration for protein and partial salt removal, electrodialysis for desalination, and electrodialysis for desalination. The multi-effect evaporation of part of the water is removed to obtain the concentrated solution of 1,3-propanediol;

Wherein, the ultrafiltration is performed by a ceramic membrane, and the filter aperture of the ceramic membrane is 5nm-50nm;

The molecular weight cut-off of the nanofiltration membrane that described nanofiltration adopts is 300D-1000D;

The ion-exchange membrane used in the electrodialysis is a heterogeneous membrane or a semi-homogeneous membrane;

The multi-effect evaporation is carried out by a multi-effect evaporator, the multi-effect evaporator is a three-effect evaporator, a four-effect evaporator, a five-effect evaporator, a six-effect evaporator or a seven-effect evaporator, and it is a reduced-pressure evaporation, The operating pressure of the final effect evaporator is -0.093～-0.099MPa;

(3) The 1,3-propanediol concentrate obtained in step (2) is dehydrated in a first rectification tower to obtain a dehydration liquid, and the dehydration liquid is distilled to obtain a 1,3-propanediol distillate; the first rectification tower The process parameter is: rectifying column theoretical plate number is 10-50, and tower top operating pressure is 88-91mmHg, and tower top reflux ratio is 0.5-1; The process parameter of described distillation is: tower top operating pressure is 10- 12mmHg;

(4) The 1,3-propanediol distillate obtained in step (3) is adsorbed and decolorized by the first decolorization tower, and the residence time of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 15-48 hours; wherein The activated carbon in the first decolorization tower is the activated carbon after the second decolorization tower of the previous batch completed the decolorization of the crude product of 1,3-propanediol;

(5) The decolorized liquid obtained after decolorization in step (4) is rectified in the second rectification tower, and 2,3-butanediol is separated from the top of the tower, and 1,3-propanediol is extracted from the bottom of the tower still. The dealcoholized liquid, the dealcoholized liquid is rectified in the third rectifying tower, and the crude product of 1,3-propanediol is extracted from the top of the tower; the process parameters of the second rectifying tower are: the number of theoretical plates of the rectifying tower 30-100, the operating pressure at the top of the tower is 17-19mmHg, and the reflux ratio is 2.8-3.1; the process parameters of the third rectifying tower are: the theoretical plate number of the rectifying tower is 20-80, and the operating pressure at the top of the tower is 5-6mmHg, the reflux ratio is 4.8-5;

(6) Use the second decolorization tower to carry out activated carbon adsorption and decolorization of the 1,3-propanediol crude product, and control the residence time of the 1,3-propanediol crude product in the second decolorization tower to be 20-48 hours to obtain purified 1,3-propanediol , the purity of the purified 1,3-propanediol is greater than or equal to 99.9%, the chromaticity is less than or equal to 10 Hazel, no peculiar smell, and the ultraviolet light absorption value at 270nm is less than or equal to 0.08;

(7) Replace all the activated carbon in the first decolorization tower with the activated carbon after decolorizing the crude product of 1,3-propanediol in the second decolorization tower, and add new activated carbon in the second decolorization tower for the next batch of bio-based 1, For the preparation of 3-propanediol, in terms of mass percentage, the new activated carbon added in the second decolorization tower accounts for 1.5-2.5% of the purified 1,3-propanediol prepared in the next batch.
A method for preparing bio-based 1,3-propanediol, characterized in that the method for preparing bio-based 1,3-propanediol is a batch-type preparation process, and the preparation method includes the following steps:

(1) Using renewable biomass as raw material, using Klebsiella to ferment 1,3-propanediol to obtain 1,3-propanediol fermentation broth;

(2) performing ultrafiltration, nanofiltration, electrodialysis, and multi-effect evaporation in sequence to obtain 1,3-propanediol concentrate;

(3) The concentrated solution is dehydrated by the first rectifying tower to obtain a dehydration liquid, and the dehydration liquid is distilled to obtain a 1,3-propanediol distillate;

(4) Adsorption and decolorization of 1,3-propanediol distillate by using the first decolorization tower; wherein the activated carbon in the first decolorization tower is the activated carbon after the decolorization of the crude 1,3-propanediol in the second decolorization tower of the previous batch;

(5) The decolorized liquid obtained after decolorization in step (4) is rectified in the second rectification tower, and 2,3-butanediol is separated from the top of the tower, and 1,3-propanediol is extracted from the bottom of the tower still. The dealcoholized liquid is rectified in the third rectifying tower, and the 1,3-propanediol crude product is extracted from the tower top;

(6) Using the second decolorization tower to decolorize the crude 1,3-propanediol by activated carbon adsorption to obtain purified 1,3-propanediol;

(7) Replace all the activated carbon in the first decolorization tower with the activated carbon after decolorizing the crude product of 1,3-propanediol in the second decolorization tower, and add new activated carbon in the second decolorization tower for the next batch of bio-based 1, Preparation of 3-propanediol.
A method for preparing bio-based 1,3-propanediol according to claim 2, characterized in that the specific implementation of step (1) is: after the fermenter is inoculated, the temperature of the fermentation broth is controlled at 30-40°C and the pH value 6-7, the ventilation rate is 0.01-0.5vvm, and the stirring rate is 20-100rpm. During the fermentation process, the glycerin 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 0.5-30g/ L, after 30-60 hours of fermentation, put into the tank.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2, is characterized in that, in step (2), described ultrafiltration adopts ceramic membrane to carry out to be used for sterilization except protein, the filtration of ceramic membrane The pore size is 5nm-50nm.
A method for preparing bio-based 1,3-propanediol according to claim 2, characterized in that the nanofiltration membrane used in the nanofiltration has a molecular weight cut-off of 300D-1000D and is used for removing protein and some salts.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2, is characterized in that, the ion-exchange membrane that described electrodialysis adopts is heterogeneous membrane or semi-homogeneous membrane, and the desalted liquid after electrodialysis desalination The conductivity drops to 2000μs/cm and below.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2 is characterized in that, the multi-effect evaporation adopts a multi-effect evaporator, and the multi-effect evaporator is a three-effect evaporator, a four-effect evaporator The evaporator, five-effect evaporator, six-effect evaporator or seven-effect evaporator is a reduced-pressure evaporation, and the operating pressure of the final effect evaporator is -0.093～-0.099MPa.
A method for preparing bio-based 1,3-propanediol according to claim 2, characterized in that in step (2), the water content of the 1,3-propanediol concentrate is controlled to be less than or equal to 40%.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2 is characterized in that, in step (3), the process parameter of the first rectification tower is: the theoretical plate number of the rectification tower is 10-50, the operating pressure at the top of the tower is 80-95mmHg, the reflux ratio at the top of the tower is 0.5-1, and the moisture content of the dehydration liquid is controlled to be less than or equal to 0.5%;

In step (3), the process parameters of the distillation are: the operating pressure at the top of the tower is 3-20mmHg.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 9, is characterized in that, in step (3), the process parameter of the first rectification tower is: the theoretical plate number of rectification tower is 10-50, the operating pressure at the top of the tower is 88-91mmHg, and the reflux ratio at the top of the tower is 0.5-1;

In step (3), the process parameters of the distillation are: the operating pressure at the top of the tower is 10-12mmHg.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2, is characterized in that, in step (4), the residence time of control 1,3-propanediol distillate in the first decolorization tower is 2- For 48 hours, control the decolorization temperature of the 1,3-propanediol distillate in the first decolorization tower to be 20-80°C.
A method for preparing bio-based 1,3-propanediol according to claim 11, characterized in that the residence time of the 1,3-propanediol distillate in the first decolorization tower is controlled to be 15-48 hours.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 2 is characterized in that, in step (5), the process parameter of the second rectification tower is: the number of theoretical plates of the rectification tower is 30-100, the operating pressure at the top of the tower is 1-30mmHg, and the reflux ratio is 2.5-30;

In step (5), the process parameters of the third rectification tower are as follows: the number of theoretical plates of the rectification tower is 20-80, the operating pressure at the top of the tower is 1-20mmHg, and the reflux ratio is 1-6.
The preparation method of a kind of bio-based 1,3-propanediol according to claim 13, is characterized in that, in step (5), the process parameter of the second rectification tower is: the number of theoretical plates of the rectification tower is 30-100, the operating pressure at the top of the tower is 15-25mmHg, and the reflux ratio is 2.5-10;

In step (5), the process parameters of the third rectification tower are as follows: the number of theoretical plates of the rectification tower is 20-80, the operating pressure at the top of the tower is 2-10 mmHg, and the reflux ratio is 3-6.
The preparation method of said a kind of bio-based 1,3-propanediol according to claim 2, is characterized in that, in step (6), the residence time of controlling 1,3-propanediol crude product in the second decolorization tower is 5 -48 hours, control the decolorization temperature of the crude 1,3-propanediol in the second decolorization tower to be 20-80°C.
The preparation method of said a kind of bio-based 1,3-propanediol according to claim 15, is characterized in that, in step (6), the residence time of controlling 1,3-propanediol crude product in the second decolorization tower is 20 -48 hours.
The preparation method of said bio-based 1,3-propanediol according to claim 1 or 2, characterized in that, in step (6), the particle size of the activated carbon in the second decolorization tower is 10-80 mesh.
The preparation method of the bio-based 1,3-propanediol according to claim 2, characterized in that, in step (6), the purity of the purified 1,3-propanediol is greater than or equal to 99.9%, and the chroma Less than or equal to 10 black Zeng, no peculiar smell, and the ultraviolet absorbance value at 270nm is less than or equal to 0.08.
The preparation method of said a kind of bio-based 1,3-propanediol according to claim 2, is characterized in that, in step (7), in terms of mass percentage, the new activated carbon added in the second decolorization tower accounts for the following 1.5-2.5% of purified 1,3-propanediol prepared in one batch.