Method for extracting polyol from a fermentation process

Abstract

A method for extracting polyol from a fermentation process is disclosed. The preparing method includes rectifying and purifying PDO (1,3-propanediol) from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is 99.5%. The preparing method meets the requirements of water resources recycling, reduces the production loss of PDO and BDO (2,3-butanediol) during the concentration, and greatly cuts down on the amount of wastewater.

Claims

1. A preparing method for extracting polyol from a fermentation process, comprising rectifying and purifying PDO (1,3-propanediol) from a polyol fermentation broth after a concentration to form a steam condensate, wherein the concentration is an evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein a retentate of a reverse osmosis flows back to the evaporative dehydration; wherein a water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; wherein a yield of the PDO is ≥99.5%.

2. The preparing method of claim 1, wherein a water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is a PDO fermentation broth after a sterilization by a filtration, or the polyol fermentation broth is the PDO fermentation broth after the sterilization by the filtration and after a desalination.

3. The preparing method of claim 2, wherein the sterilization by the filtration is performed by at least one selected from the group consisting of a microfiltration membrane filtration, an ultrafiltration and a nanofiltration.

4. The preparing method of claim 2, wherein the desalination is at least one selected from the group consisting of a concentrated crystallization desalination, an electrodialysis desalination, a chromatographic separation desalination and an ion exchange desalination.

5. The preparing method of claim 2, wherein the desalination is a one-step desalination or a multi-step desalination.

6. The preparing method of claim 1, wherein the concentration is a one-step concentration or a stepwise concentration.

7. The preparing method of claim 6, wherein the stepwise concentration is a two-step concentration or a three-step concentration.

8. The preparing method of claim 7, wherein the two-step concentration comprises the following steps: performing a primary concentration on the concentrated solution is primary concentrated until the water content of the concentrated solution is 50-70 wt %; after 80-99 wt % of a salt is removed, performing a secondary concentration on the concentrated solution is secondary concentrated until the water content of the concentrated solution is 5-25 wt %.

9. The preparing method of claim 7, wherein the three-step concentration comprises the following steps: performing a primary concentration on the concentrated solution is primary concentrated until the water content of the concentrated solution is 50-70 wt %; after 30-60 wt % of a salt is removed, performing a secondary concentration on the concentrated solution is secondary concentrated until the water content of the concentrated solution is 30-50 wt %; before a third step of the three-step concentration, performing a desalination on the concentrated solution is desalted again until a total desalination rate of the concentrated solution is 80-99 wt %; then performing a tertiary concentration on the concentrated solution until the water content of the concentrated solution is 5-25 wt %.

10. The preparing method of claim 1, wherein the concentration is a multi-effect evaporative concentration, an MVR evaporative concentration or a multi-effect rectification.

11. The preparing method of claim 10, wherein the multi-effect evaporative concentration refers to a steam of a former effect as a heat source of a latter effect, and the multi-effect evaporative concentration comprises a three-effect evaporative concentration, a four-effect evaporative concentration, a five-effect evaporative concentration and a six-effect evaporative concentration.

12. The preparing method of claim 1, wherein the reverse osmosis is a one-stage reverse osmosis or a multi-stage reverse osmosis.

13. The preparing method of claim 12, wherein the multi-stage reverse osmosis refers to two or more stages of the reverse osmosis, the multi-stage reverse osmosis connects the reverse osmosis in series, and the retentate of a subsequent stage flows back to a previous stage while the retentate of the previous stage flows back to the evaporative dehydration.

14. The preparing method of claim 12, wherein the multi-stage reverse osmosis refers to two or more stages of the reverse osmosis, the multi-stage reverse osmosis connects the reverse osmosis in series; at the same time, the retentate of a first-stage reverse osmosis is further filtered through a second-stage reverse osmosis, while a penetrant of the first-stage reverse osmosis and the second-stage reverse osmosis flows out, and the retentate of the second-stage reverse osmosis flows back to a multi-effect evaporation for the evaporative dehydration.

15. The preparing method of claim 12, wherein the multi-stage reverse osmosis refers to two or more stages of the reverse osmosis, the multi-stage reverse osmosis connects the reverse osmosis in series; at the same time, the retentate of a first-stage reverse osmosis is further filtered through a second-stage reverse osmosis, while a penetrant of the first-stage reverse osmosis and the second-stage reverse osmosis flows out; then the retentate of the second-stage reverse osmosis is further filtered through a third-stage reverse osmosis, and the retentate of the third-stage reverse osmosis flows back to a multi-effect evaporation for the evaporative dehydration, while a penetrant of the third-stage reverse osmosis flows back to a raw material of the first-stage reverse osmosis.

16. The preparing method of claim 12, wherein the multi-stage reverse osmosis refers to two or more stages of the reverse osmosis, which the multi-stage reverse osmosis connects the reverse osmosis in series; at the same time, a penetrant of a first-stage reverse osmosis is further filtered through a second-stage reverse osmosis, and a penetrant of the second-stage reverse osmosis flows out, while the retentate of the first-stage reverse osmosis is further filtered through a third-stage reverse osmosis, and the retentate of the third-stage reverse osmosis flows back to a multi-effect evaporation for the evaporative dehydration; then the retentate of the second-stage reverse osmosis and a penetrant of the third-stage reverse osmosis flows back to a raw material of the first-stage reverse osmosis.

17. The preparing method of claim 1, wherein products of a rectification and a purification comprise the PDO and BDO (2,3-butanediol).

18. The preparing method of claim 1, wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by genetic engineering bacteria of the Klebsiella, the Clostridium, the Citrobacter, the Lactobacillus, the Corynebacterium glutamicum or the Escherichia coli.

19. The preparing method of claim 1, wherein a penetrant of the reverse osmosis is reused as a fermentation ingredient, as cleaning water or fora sewage treatment.

20. The preparing method of claim 6, wherein the concentration is a multi-effect evaporative concentration, an MVR evaporative concentration or a multi-effect rectification.

21. The preparing method of claim 7, wherein the concentration is a multi-effect evaporative concentration, an MVR evaporative concentration or a multi-effect rectification.

22. The preparing method of claim 8, wherein the concentration is a multi-effect evaporative concentration, an MVR evaporative concentration or a multi-effect rectification.

23. The preparing method of claim 9, wherein the concentration is a multi-effect evaporative concentration, an MVR evaporative concentration or a multi-effect rectification.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a flowchart of Example 1;

(2) FIG. 2 is a flowchart of Example 2;

(3) FIG. 3 is a flowchart of Example 3;

(4) FIG. 4 is a flowchart of Example 4;

(5) FIG. 5 is a flowchart of Example 5;

(6) FIG. 6 is a flowchart of Example 6;

(7) Among these Figures, 1 is the concentration, 1A is the primary concentration, 1B is the secondary concentration, 2 is the reverse osmosis, 2A is the first-stage reverse osmosis, 2B is the second-stage reverse osmosis, 2C is the third-stage reverse osmosis, 3 is the fermentation, 4 is the fermentation broth, 5 is the steam condensate (including primary and secondary steam condensate), 6 is the retentate of the reverse osmosis, 6A is the retentate of the first-stage reverse osmosis, 6B is the retentate of the second-stage reverse osmosis, 6C is the retentate of the third-stage reverse osmosis, 7 is the penetrant of the reverse osmosis, 7A is the penetrant of the first-stage reverse osmosis, 7B is the penetrant of the second-stage reverse osmosis, 7C is the penetrant of the third-stage reverse osmosis, 8 is the desalination, 8A is the primary desalination, 8B is the secondary desalination, 9 is the desalted solution, 9A is the primary desalted solution, 9B is the secondary desalted solution, 10 is the concentrated solution, 10A is the primary concentrated solution, 10B is the secondary concentrated solution.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) Based on above mentioned method, the following embodiments are carried out for further demonstration in the present invention. It is to be understood that these embodiments are only intended to illustrate the invention and are not intended to limit the scope of the invention. In addition, it should be understood that after reading the contents described in the present invention, those technical personnel in this field can make various changes or modifications to the invention, and these equivalent forms also fall within the scope of the claims attached to the application.

Example 1

(9) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(10) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after one-step desalination as the electrodialysis desalination; wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(11) wherein the concentration of the polyol fermentation broth is one-step concentration as the multi-effect evaporative concentration, which refers to the steam of the former effect as the heat source of the latter effect, including a three-effect evaporation, a four-effect evaporation, a five-effect evaporation and a six-effect evaporation;

(12) wherein the reverse osmosis is one-stage reverse osmosis.

(13) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 1: the fermentation broth 4 for the desalination 8.fwdarw.the desalted solution 9 for the concentration 1.fwdarw.the concentrated solution 10 for purification through the bottom of the rectification tower while the steam condensate (including primary and secondary steam condensate) 5 for the reverse osmosis 2.fwdarw.the penetrant of the reverse osmosis 7 for the fermentation 3 while the retentate of the reverse osmosis 6 for the concentration 1.

(14) Specifically, the polyol fermentation broth is dehydrated by the multi-effect evaporation, and the steam condensate (including primary and secondary steam condensate) is filtered by first-stage reverse osmosis, wherein the operating pressure of reverse osmosis is 2.5 MPa, the operating temperature is 35-36° C., the operating process is shown in FIG. 1, and the experimental data is shown in Table 1.

(15) TABLE-US-00001 TABLE 1 Statistics of the multi-effect evaporation of fermentation broth and the reverse osmosis of condensate Mass Water PDO BDO Glycerin Ethanol Materials (kg) (g/l) (g/l) (g/l) (g/l) (g/l) Polyol 210 883.10 78.00 28.70 5.60 4.60 fermentation broth Multi-effect 220 992.33 2.2 3.75 0 1.72 evaporative steam condensate Penetrant of 198 998.33 1.06 0.44 0 1.86 reverse osmosis Retentate of 22 956.59 12.25 28.02 0 3.14 reverse osmosis

Example 2

(16) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(17) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after one-step desalination as the electrodialysis desalination; wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(18) wherein the concentration of the polyol fermentation broth is one-step concentration as the MVR evaporative concentration;

(19) wherein the reverse osmosis is two-stage reverse osmosis, which connects the reverse osmosis in series, and the retentate of the subsequent stage flows back to the previous stage while the retentate of the previous stage flows back to the evaporative dehydration.

(20) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 2: the fermentation broth 4 for the desalination 8.fwdarw.the desalted solution 9 for the concentration 1.fwdarw.the concentrated solution 10 for purification through the bottom of the rectification tower while the steam condensate (including primary and secondary steam condensate) 5 for the first-stage reverse osmosis 2A.fwdarw.the penetrant of the first-stage reverse osmosis 7A for the second-stage reverse osmosis 2B while the retentate of the first-stage reverse osmosis 6A for the concentration 1.fwdarw.the penetrant of the second-stage reverse osmosis 7B for the fermentation 3 while the retentate of the second-stage reverse osmosis 6B for the first-stage reverse osmosis 2A.

(21) Specifically, the polyol fermentation broth is dehydrated by the multi-effect evaporation, and the steam condensate (including primary and secondary steam condensate) is filtered by first-stage reverse osmosis, then filtered by second-stage reverse osmosis after the penetrant of the first-stage reverse osmosis is recycled, wherein the operating pressure of first-stage and second-stage reverse osmosis is 2.5 MPa, the operating temperature is 35-36° C., the operating process is shown in FIG. 2, and the experimental data is shown in Table 2.

(22) TABLE-US-00002 TABLE 2 Statistics of the multi-effect evaporation of fermentation broth and the reverse osmosis of condensate Mass Water PDO BDO Glycerin Ethanol Materials (kg) (g/l) (g/l) (g/l) (g/l) (g/l) Polyol 252 882.10 77.20 29.30 6.20 5.20 fermentation broth Multi-effect 272 996.8 3.18 7.95 0 3.74 evaporative steam condensate Retentate of 22 979.5 20.48 65.70 0 6.16 first-stage reverse osmosis Penetrant of 250 999 0.96 0.67 0 3.05 first-stage reverse osmosis Retentate of 22 992.8 7.18 5.39 0 8.34 second-stage reverse osmosis Penetrant of 228 999.9 0.15 0.03 0 2.19 second-stage reverse osmosis

(23) The penetrant of reverse osmosis in Example 1 is used to prepare the fermentation base materials, including PDO 0.37 g/l, BDO 0.11 g/l and ethanol 1.31 g/l, whose fermentation level of PDO for 48 h fermentation is 100.94 g/l, and the bacteria concentration (650 nm absorbance value) is 14.96 for 24 h fermentation;

(24) The penetrant of second-stage reverse osmosis in Example 2 is used to prepare the fermentation base materials, including PDO 0.17 g/l, BDO 0 g/l, and ethanol 4.26 g/l, whose fermentation level of PDO for 48 h fermentation is 92.62 g/l, and the bacteria concentration (650 nm absorbance value) is 14.94 for 24 h fermentation;

(25) Pure water is used as a fermentation ingredient, whose fermentation level of PDO for 48 h fermentation is 94.32 g/l, and the bacterial concentration (650 nm absorbance value) is 13.42 for 24 h fermentation;

(26) The multi-effect evaporative steam condensate in Example 1 is directly used as a fermentation ingredient. The fermentation base materials include PDO 2.2 g/l, BDO 3.75 g/l, and ethanol 1.72 g/l, whose fermentation level of PDO for 48 h fermentation is 85.36 g/l, and the bacteria concentration (650 nm absorbance value) is 12 for 24 h fermentation.

Example 3

(27) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(28) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after one-step desalination as the chromatographic desalination; wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(29) wherein the concentration of the polyol fermentation broth is one-step concentration as the multi-effect rectification;

(30) wherein the reverse osmosis is two-stage reverse osmosis, which connects the reverse osmosis in series, and the retentate of the first-stage reverse osmosis is further filtered through the second-stage reverse osmosis, while the penetrant of the first-stage and second-stage reverse osmosis flows out, and the retentate of the second-stage reverse osmosis flows back to the multi-effect evaporation for evaporative dehydration.

(31) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 3: the fermentation broth 4 for the desalination 8.fwdarw.the desalted solution 9 for the concentration 1.fwdarw.the concentrated solution 10 for purification through the bottom of the rectification tower while the steam condensate (including primary and secondary steam condensate) 5 for the first-stage reverse osmosis 2A.fwdarw.the penetrant of the first-stage reverse osmosis 7A for the fermentation 3 while the retentate of the first-stage reverse osmosis 6A for the second-stage reverse osmosis 2B.fwdarw.the penetrant of the second-stage reverse osmosis 7B for the fermentation 3 while the retentate of the second-stage reverse osmosis 6B for the concentration 1.

Example 4

(32) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(33) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after one-step desalination as the ion exchange desalination; wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(34) wherein the concentration of the polyol fermentation broth is one-step concentration as the MVR evaporative concentration;

(35) wherein the reverse osmosis is three-stage reverse osmosis, which connects the reverse osmosis in series, and the retentate of the first-stage reverse osmosis is further filtered through the second-stage reverse osmosis, while the penetrant of the first-stage and second-stage reverse osmosis flows out; then the retentate of the second-stage reverse osmosis is further filtered through the third-stage reverse osmosis, and the retentate of the third-stage reverse osmosis flows back to the multi-effect evaporation for evaporative dehydration, while the penetrant of the third-stage reverse osmosis flows back to the raw material of the first-stage reverse osmosis.

(36) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 4: the fermentation broth 4 for the desalination 8.fwdarw.the desalted solution 9 for the concentration 1.fwdarw.the concentrated solution 10 for purification through the bottom of the rectification tower while the steam condensate (including primary and secondary steam condensate) 5 for the first-stage reverse osmosis 2A.fwdarw.the penetrant of the first-stage reverse osmosis 7A for the fermentation 3 while the retentate of the first-stage reverse osmosis 6A for the second-stage reverse osmosis 2B.fwdarw.the penetrant of the second-stage reverse osmosis 7B for the fermentation 3 while the retentate of the second-stage reverse osmosis 6B for the third-stage reverse osmosis 2C.fwdarw.the penetrant of the third-stage reverse osmosis 7C for the first-stage reverse osmosis 2A while the retentate of the third-stage reverse osmosis 6C for the concentration 1.

Example 5

(37) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(38) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after one-step desalination as the concentrated crystallization desalination; wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(39) wherein the concentration of the polyol fermentation broth is one-step concentration as the multi-effect rectification;

(40) wherein the reverse osmosis is three-stage reverse osmosis, which connects the reverse osmosis in series, and the penetrant of the first-stage reverse osmosis is further filtered through the second-stage reverse osmosis, and the penetrant of the second-stage reverse osmosis flows out, while the retentate of the first-stage reverse osmosis is further filtered through the third-stage reverse osmosis, and the retentate of the third-stage reverse osmosis flows back to the multi-effect evaporation for evaporative dehydration; then the retentate of the second-stage reverse osmosis and the penetrant of the third-stage reverse osmosis flows back to the raw material of the first-stage reverse osmosis.

(41) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 5: the fermentation broth 4 for the desalination 8.fwdarw.the desalted solution 9 for the concentration 1.fwdarw.the concentrated solution 10 for purification through the bottom of the rectification tower while the steam condensate (including primary and secondary steam condensate) 5 for the first-stage reverse osmosis 2A.fwdarw.the penetrant of the first-stage reverse osmosis 7A for the second-stage reverse osmosis 2B while the retentate of the first-stage reverse osmosis 6A for the third-stage reverse osmosis 2C.fwdarw.the penetrant of the second-stage reverse osmosis 7B for the fermentation 3, the retentate of the second-stage reverse osmosis 6B for the first-stage reverse osmosis 2A, the penetrant of the third-stage reverse osmosis 7C for the first-stage reverse osmosis 2A, and the retentate of the third-stage reverse osmosis 6C for the concentration 1.

Example 6

(42) A preparing method for extracting polyol from a fermentation process, which is characterized by rectifying and purifying PDO from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%; wherein the products of rectification and purification include PDO as well as BDO;

(43) wherein the water content of the polyol fermentation broth is ≥80 wt %; wherein the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration (a sterilization by microfiltration membrane filtration); wherein the polyol fermentation broth is fermented by Klebsiella, Clostridium, Citrobacter, Lactobacillus, Corynebacterium glutamicum or Escherichia coli, or by the genetic engineering bacteria of these bacteria;

(44) wherein the concentration is two-step concentration, the concentrated solution is primary concentrated until the water content is 50-70 wt %; after 80-99 wt % salt is removed, the concentrated solution is secondary concentrated until the water content is 5-25 wt %; wherein the concentration is the multi-effect evaporative concentration, which refers to the steam of the former effect as the heat source of the latter effect, including a three-effect evaporation, a four-effect evaporation, a five-effect evaporation and a six-effect evaporation;

(45) wherein the reverse osmosis is one-stage reverse osmosis.

(46) The process of a preparing method for extracting polyol from a fermentation process is shown in FIG. 6: the fermentation broth 4 for the primary concentration 1A.fwdarw.the primary concentrated solution 10A for the primary desalination 8A while the steam condensate (including primary and secondary steam condensate) 5 for the reverse osmosis 2.fwdarw.the primary desalted solution 9A for the secondary desalination 8B, the penetrant of the reverse osmosis 7 for the fermentation 3, and the retentate of the reverse osmosis 6 for the primary concentration 1A.fwdarw.the secondary desalted solution 9B for the secondary concentration 1B.fwdarw.the secondary concentrated solution 10B for purification through the bottom of the rectification tower.

Example 7

(47) A preparing method for extracting polyol from a fermentation process, which is basically the same as Example 5, except that the polyol fermentation broth is the PDO fermentation broth after sterilization by filtration, and after multi-step desalination (combination of the concentrated crystallization desalination and the electrodialysis desalination).

Example 8

(48) A preparing method for extracting polyol from a fermentation process, which is basically the same as Example 6, except that the concentration is three-step concentration. The concentrated solution is primary concentrated until the water content is 50-70 wt %; after 30-60 wt % salt is removed, the concentrated solution is secondary concentrated until the water content is 30-50 wt %; before the third step, the concentrated solution is desalted again until the total desalination rate is 80-99 wt %; then the concentrated solution is tertiary concentrated until the water content is 5-25 wt %.

Example 9

(49) A preparing method for extracting polyol from a fermentation process, which is basically the same as Example 6, except that the sterilization by filtration is the sterilization by ultrafiltration.

Example 10

(50) A preparing method for extracting polyol from a fermentation process, which is basically the same as Example 6, except that the sterilization by filtration is the sterilization by nanofiltration.

Example 11

(51) A preparing method for extracting polyol from a fermentation process, which is basically the same as Example 6, except that the sterilization by filtration is a combination of the sterilization by microfiltration membrane filtration and the sterilization by ultrafiltration.